AEES-14
The Use of Ethanolas an UnmixedFuel
for lnternalCombustionEngines
by
JosephL. Taraba
Extension
istfor Agricultural Engineering
Special
GeorgeM. Turner
Extensi
on Special
istf or Agricultural Engineering
RobertRazor
Undergrad
uateStudent,Department
of Agricultural Eng ineering
Department
of Agricultural
Engineering
University
of Kentucky
Lexington,
Kentucky
February1981
U N I V E R S I T Yo f K E N T U C K Y
in
COLLEGEof AGRICULTURE
coogerolion
OEPT.of AGRIC.ENGINEERING
with
COOPERATIVE
EXTENSIONSERVICE
KENTUCKY
DEPARTMENT
of
ENERGY
Preface
A committeeof the AgriculturalEngineeringDepartment,Universityof Kentucky,of
which the authorsare members,is investigatingthe feasibilityof certainfarmersbecoming
e n e r g yi n d e p e n d e nbt y p r o d u c i n gt h e i ro w n e n g i n ef u e l .
A part of this investigationconcernsjust how low a proof of ethanolcan be toleratedby
internalcombustionenginesfrom severalaspects.Naturally,the lowerthe proofthe easierthe
p r o d u c t i o nw i l l b e .
This paperdescribesthe resultsof a literaturesearchon the effect of water dilution in
ethanolon the combustionprocessin internalcombustionengines.
CONTENTS
I n t r o d u c t i o .n. . .
... . ... . 3
Proof of EthanolTolerableby InternalCombustionEngines
. .. . 3
M e c h a n i c aM
l o d i f i c a t i o nR
s e q u i r e df o r U s e o f E t h a n o a
l s a F u e li n a S l E n g i n e
.... 5
e ot hf a n o l a s a F u ei ln a D i e s e lE n g i n e . . . . . 1 0
M e c h a n i c aMl o d i f i c a t i o n s R e q u i r e d f o r U s E
C o m p a r i s o n oEf n g i n e P e r f o r m a n c e o n E t h aannodl C o n v e n t i o n F
a lu e l s .
S a f e t yi n H a n d l i n gE t h a n o l
........11
.. . . 13
D e t e r i o r a t i oonf M a t e r i a l si n C o n t a c tw i t h E t h a n o l. . . .
.. ... .. . 14
P o l l u t a nE
t m i s s i o n sL e v e l so f E n g i n e sU s i n gE t h a n o l
. .. 14
y s i n gE t h a n o l
E n g i n eD u r a b i l i t U
D e p o s i t si n E n g i n e sU s i n g E t h a n o l
.... 16
.. . . . . .. 17
Conclusion
...... 17
Glossaro
yf Terms
...... 18
Bibliography.....
......19
In tro d u cti o n
T h e u s e o f e t h a n o l( e t h y la l c o h o l )a s a f u e l f o r
s p a r ki g n i t e d( S l ) . i n t e r n acl o m b u s t i o ne n g i n e sh a s
been evaluatedand consideredsatisfactorysince
the early1900s.Today due to the increasingcost of
p e t r o l e u ma n d t h e c u r r e n t w o r l d o i l u n c e r t a i n t y ,
w h i c h m a y g r e a t l ya f f e c tt h e f u t u r e a v a i l a b i l i t yo f
p e t r o l e u ms, o m ea l t e r n a t i v feu e l sf o r i n t e r n acl o m b u s t i o ne n g i n e sa r e n e e d e d .E t h a n o li s o n e o f t h e
f u e l st h a t h a ss h o w np r o m i s ea sa p e t r o l e u ms u b s t i tute. Today the country of Brazilhas chosena path
o f l e s sd e p e n d e n c e
o n p e t r o l e u mb y d e v e l o p i n ga n
e t h a n o lf u e l t e c h n o l o g y I. n t h e s p r i n go f 1 9 8 0 ,c a r s
designedto run exclusivelyon ethanolwereoffered
f o r s a l e t o t h e B r a z i l i a np u b l i c . B r a z i l h a s a l s o
e n c o u r a g e di t s c i t i z e n st o u s ee t h a n o lb y m a k i n gi t
a v a i l a b l et o t h e c o n s u m e ra t h a l f t h e c o s t o f g a s o line.
T h i s p a p e r r e v i e w st h e u s e o f e t h a n o l a s a n
u n m i x e df u e l f o r i n t e r n a cl o m b u s t i o ne n g i n e s A
. nh y d r o u s e t h a n o l ( n o w a t e r p r e s e n t )i s r e q u i r e d
w h e nf u e l m i x t u r e sa r em a d ew i t h g a s o l i n eo r d i e s e l
f uel.Presenceof greaterthan 1.50/o
waterin ethanol
w i l l c a u s es e p a r a t i o no f t h e e t h a n o lf r o m t h e p e t r o l e u m f u e l . O n - f a r m p r o d u c t i o no f e t h a n o lw i l l
yield ethanolf uel with at least50/o
water presentor
present.
Thus,on-farmethanolf uel
up to 50%water
p r o d u c t i o n w o u l d n e c e s s i t a t ea d a p t i n g i n t e r n a l
c o m b u s t i o ne n g i n e sf o r u s e o f u n m i x e d e t h a n o l
fuel.
Severalbasicf uel propertiesof ethanolin comoarison to other conventionalfuels need to be
noted becauseof theireffectson the use of ethanol
a s a f u e l f o r i n t e r n a cl o m b u s t i o ne n g i n e s S
. o m eo f
t h e f u e lp r o p e r t y c o m p a r i s o nasr es h o w ni n T a b l e1 .
C o n v e n t i o n ahl y d r o c a r b o nf u e l s( g a s o l i n ea n d
d i e s e l o i l ) c o n t a i n 1 8 , 9 0 0a n d 1 8 , 2 5 0B t u / l b i n
c o m p a r i s o nt o e t h a n o l , w h i c h c o n t a i n s 1 1 , 5 0 0
B t u / l b .I n o r d e rt o a c h i e v ee q u i v a l e net n g i n ep o w e r
o u t o u t f o r d i f f e r e n tf u e l s t h e r e m u s t b e s i m i l a r
e n e r g y i n p u t , a s f u e l . F o r e x a m p l e ,p u r e e t h a n o l
c o n t a i n s6 1 % o f t h e e n e r g y o f g a s o l i n ep e r u n i t
weight, thereforemore pounds of ethanol are req u i r e d t h a n g a s o l i n ef o r e q u i v a l e net n g i n e p u w e r
o u t p u t .l f a n e t h a n o fl u e l c o n t a i n sw a t e r ,w h i c h h a s
n o c o m b u s t i o ne n e r g y ,t h e r em u s t b e a n i n c r e a s e d
f u e l r a t e t o t h e e n g i n e t o s u p p l y s u f f i c i e n ti n p u t
energy.
Anotherimportantdifferencebetweenconvent i o n a lf u e l sa n d e t h a n o li s t h e h e a to f v a p o r i z a t i o n .
E t h a n o lr e q u i r e s3 6 1 B t u / l b t o v o l a t i l i z ew
, hich is
a p p r o x i m a t e l y2 . 5 t i m e s t h e h e a t r e q u i r e d p e r
p o u n do f g a s o l i n eo r d i e s e fl u e l .W a t e rh a sa h e a to f
v a p o r i z a t i o 2n . 7t i m e st h a t o f a l c o h o l .
T h e a u t o - i g n i t i o np r o p e r t yo f a f u e l b e c o m e s
i m p o r t a n tf o r t h e t y p e e n g i n ei n w h i c h t h e f u e l i s
u s e d .T h e o c t a n en u m b e rm e a s u r e st h e r e s i s t a n c e
to self-ignition
w h i l e t h e c e t a n en u m b e rm e a s u r e s
propert h e e a s eo f s e l f - i g n i t i o nL.o w a u t o - i g n i t i o n
(
h
i
g
h
ties
o c t a n en u m b e ra n d l o w c e t a n en u m b e r )
a r ed e s i r a b l e
f o r s p a r ki g n i t i o ne n g i n e sE
. t h a n oal n d
g a s o l i n eb o t h i n d i c a t eh i g h o c t a n ea n d l o w c e t a n e
n u m b e r s .B u t d i e s e le n g i n e sr e q u i r ea h i g h a u t o i g n i t i o nv a l u ef u e l ( h i g hc e t a n en u m b e r ,l o w o c t a n e
number)w
, h i c h d i e s e lf u e l d o e sp o s s e s s .
F i n a l l yt h e a i r - fu e l r a t i ot o a c hi e v et h e c o mp l e t e
b u r n i n g o f t h e f u e l ( s t o i c h i o m e t r i cA / F r a t i o ) i s
1 4 . 7 : 1' f o rg a s o l i n eb u t o n l y 9 : 1f o r e t h a n o l T
. h i sf u e l
propertyrequi res carburetor f uel-rateadjustments
t o a c h i e v em a x i m u me n g i n ee f f i c i e n c y .
Proofof EthanolTolerableby
InternalGombustion
Engines
T h e p r o o f o f a l c o h o lt o l e r a b l eb y a n i n t e r n a l
c o m b u s t i o ne n g i n e i s o n e o f t h e m o s t i m p o r t a n t
Table 1.-Fuel Properties.
Heatof
Combusion
Btu/lb
Gasoline
D i e s e lF u e l
Ethanol
Water
- A b b r e v i a t i o n sa r e
18,900
18,250
11,500
Density
lb/gal
Heat of
Vaporization
Btu/lb
6.2
7.3
o.o
8.3
d e f i n e da t t h e e n d o f t h e p u b l i c a t i o n .
142
115
361
970
Octane
Number
Cetane
Number
Stoichiometric
A i r / F u e lR a t i o
77-86
10-30
89
10-20
14.7
15.0
9.0
AE,
20-10
f a c t o r s t h a t m u s t b e c o n s i d e r e di n t h e u s e o f
e t h a n o lE
. t h a n o il s c o n c e n t r a t e d u r i n gt h e d i s t i l l a t i o n o f a m i x t u r eo f e t h a n o a
l n d w a t e r .E a c ht i m e t h e
m i x t u r e i s d i s t i l l e d ,i t s p r o o f ( t w o t i m e s t h e p e r c e n t a g ec o n t e n to f t h e a l c o h o li n t h e a l c o h o lw a t e r
solution) increases.Therefore, the lower proof
( h i g h e rt h e w a t e r c o n t e n t )e t h a n o l i s c h e a p e rt o
p r o d u c e a n d e c o n o m i c a l l ym o r e a t t r a c t i v ea s a
o e t r o l e u ms u b s t i t u t e .
T h e u s e o f e t h a n o li n a n i n t e r n a lc o m b u s t i o n
e n g i n ew i t h a p r o o fa s l o w a s 7 0 h a s b e e nr e p o r t e d
( S c h r o c k ,1 9 7 9 ) . B u t i n a t e s t d o n e o n a 1 9 4 7
P l y m o u t he n g i n ea t w i d e o p e n t h r o t t l e( W O T )w i t h
t h e i g n i t i o n ,s p a r kt i m i n g a n d a i r - f u e lr a t i oc a r b u retoradjustedfor maximumpower,and usinghotter
s p a r kp l u g s t h a n f o r n o r m a lg a s o l i n eo p e r a t i o n i,t
was f ound that as the proof of alcohol decreases,
the horsepower and thermal efficiency decrease
The results of
whilethe f uel consumptionincreases.
t h i s t e s ta r e s h o w n i n T a b l e2 ( S c h r o c k 1, 9 7 9 ) .
A n o t h e rt e s t o e r f o r m e do n a n O l i v e ri n - l i n es i x c y li n d e re n g i n ew i t h a h e a t e rf o r t h ea ir - fu e l m i x t ur e
s h o w e d s l i g h t l y d i f f e r e n tr e s u l t sf o r t h e t h e r m a l
e f f i c i e n c yT. h e r e s u l t si n d i c a t e dt h a t a s w a t e rw a s
a d d e dt o 2 0 0 p r o o f a l c o h o lt h e t h e r m a le f f i c i e n c y
i n c r e a s e du n t i l t h e m i x t u r e w a s 1 8 0 p r o o f , t h e n
d e c r e a s e da s i n c r e a s i n ga m o u n t s o f w a t e r w e r e
a d d e d .H o w e v e r ,t h e p o w e r o u t p u t o f t h e e n g i n e
was maximumat 200 proof (Deardorff,1979).
fhese testsindlcate that the higher proof ethanol is a more desirable fuel. But as before, the
e c o n o m i c sm u s tc o n s i d e rm o r et h a nj u s tt h ec o s to f
t h ef u e l .
Lower proof ethapol also has caused some
. u r d e t h a n o rl e q u i r e sm o r e h e a t
e n g i n ep r o b l e m s P
per gallon for vaporizationthan gasolineor diesel
f u e l .F u r t h e r t, h e l o w e rt h e p r o o fo f t h e e t h a n o lt h e
more Btu of heat per gallon for vaporizationare
r e q u i r e db e c a u s eo f t h e h i g h h e a to f v a p o r i z a t i o on f
water.Therefore,more heatis neededfor the intake
m a n i f o l d( H u n t ,1 9 7 9 ) .I n t h e t w o t e s t sm e n t i o n e d
p r e v i o u s l y t, h e f a c t t h a t t h e O l i v e re n g i n e h a d a
h e a t e rf o r t h e a i r - f u e lm i x t u r e a n d t h e P l y m o u t h
e n g i n ed i d n o t ,m a y h a v ec a u s e dt h e d i s c r e p a n c iyn
. u r t h e r l, o w e rp r o o f
t h e t h e r m a le f f i c i e n c yr e s u l t s F
ethanolfuels (168proof) havealso producedstarti n g p r o b l e m s( H u n t ,1 9 8 0 ) .
O i l d i l u t i o nh a s a l s o b e e n r e p o r t e dd u r i n g u s e
of lower proof ethanol. ln a test performedon the
1 9 4 7P l y m o u t he n g i n e o, i l d i l u t i o nw a se n c o u n t e r e d
w h e nu s i n g7 0 p r o o fe t h a n o lA
. t W O T t h ee n g i n er a n
s m o o t h l yo n 7 0 p r o o fe t h a n o lb u t w a s i n c o n s i s t e n t
i n i t s o o e r a t i o n .B u t u n d e r t h e s es a m e c o n d i t i o n s
r u n n i n g t h e e n g i n e f o r o n e h o u r r e s u l t e di n t h e
from6 to 8 quarts,
c r a n k c a s eo i l v o l u m ei n c r e a s i n g
d u e t o t h e d i l u t i o no f t h e o i l b y t h e a l c o h o la n dw a t e r
( S c h r o c k ,1 9 7 9 ) .O i l d i l u t i o nc a n b e o v e r c o m eo r
g r e a t l yr e d u c e db y r a i s i n gt h e c o o l i n gw a t e rt e m perature by changing thermostats(Deardorff,
19 7 9 ) .
W i t h o u t h e a t a d d i t i o nt o t h e f u e l - a i rm i x t u r e ,
the temperature
o f t h e c h a r g ee n t e r i n gt h e e n g i n e
c y l i n d e ri s l o w e r f o r e t h a n o lo r e t h a n o l - w a t efru e l
t h a n g a s o l i n e .T h i s r e s u l t s i n a d e n s e r f u e l - a i r
charge to the cylinderand a higher volumetric
e f f i c i e n c yf o r a n e n g i n ef u e l e d w i t h e t h a n o lo v e r
gasoline.
Table 2.-Engine Performanceon VariousProof Alcohol.
Proof
Brake
Horsepower
200
190
180
160
140
120
110
100
90
80
70
47.67
46.18
46.67
45.07
45.58
43.60
42.00
42.94
42.35
41.40
34.10
Blend
Ethanol
Consumption Consumption
lb/bhp-hr
Gal/hr
6.85
7.53
7.94
9.52
11.33
12.90
14.53
19.00
17.90
20.87
26.70
.944
1.029
1.042
1.127
1.162
1.207
1.278
1.490
1.277
1.341
'1.853
Thermal
Efficiencya
21.2
19.4
19.2
t t.o
17.2
to.o
15.6
13.4
15.6
14.9
10.8
a H i g h e r h e a t i nvga l u eu s e db y t h i s s t u d y ( D u c k e t a l 1. ,9 4 5 t)o c a l c u l a t e t h e r m a l e f f i c i e n c y
Optimum
SparkAdvance
17.5
zu.+
21.3
27.0
29.0
33.0
35.0
36.0
41.5
47.O
50.0
One interesting fact about the lower proof
ethanol is that it may be able to withstandgreater
i n c r e a s e si n t h e c o m p r e s s i o nr a t i ot h a n t h e h i g h e r
p r o o f ( H u n t ,1 9 8 0 ) .l f t h i s i s t r u e t h e p o w e ro u t p u t
a n d t h ee n g i n e e f f i c i e n c y w o u b
l de i n c r e a s e fdo r t h e
l o w e r o r o o fe t h a n o l .
Ethanol is more suitable for use in spark ignition engines than in diesel engines because of
ethanol'shigh octanenumber (the octanenumber
and the cetane number are inverselyrelated).The
c e t a n en u m b e ro f e t h a n o lc a n b e r a i s e db y t h e u s e
o f a d d i t i v e s .A m y l n i t r a t e i s a n a d d i t i v et h a t i s
popular in the UnitedStates.A 1.50/o
mixtureof amyl
n i t r a t ei n e t h a n o li n c r e a s e st h e c e t a n en u m b e ro f
e t h a n o lb y 1 5 p o i n t s .H o w e v e r ,n o r e p o r t so n t h e
p e r f o r m a n c eo f a d i e s e le n g i n eu s i n g e t h a n o la n d
a m y l n i t r a t eh a v eb e e nf o u n d ( S c h r o c k 1, 9 7 9 ) .
C y c l o h e x a n oils a n a d d i t i v et h a t i s p o p u l a ri n
Europe.When it makes up 100/o
of a mixture with
e t h a n o l ,t h e c e t a n en u m b e r o f e t h a n o l i s c o m p a r a b l et o t h a to f d i e s e fl u e l .A d i e s e el n g i n ec a n b e r u n
o n t h i s m i x t u r ew i t h n o m a j o rc h a n g e st o t h ee n g i n e
(Schrock,1979).
MechanicalModificationsRequiredfor
U s e o f Et h a n o la s a F u e l i n a S l E n gine
W h e n g a s o l i n et h a t c o n t a i n sm o r e t h a n 2 5 %
e t h a n o li s u s e d i n a S l e n g i n e ,s o m e m o d i f i c a t i o n
m u s t b e m a d et o t h e e n g i n e( F l o w e r se t a l . , ' 1 9 7 9 ) .
T h i s o f c o u r s ei n c l u d e se t h a n o l - w a t ebr l e n d st h a t
c o n t a i nn o g a s o l i n eT. h e m o d i f i c a t i o n ds e p e n do n
t h e e n g i n ea n d w h a t i s r e q u i r e do f t h e e n g i n e .
But before mechanical modifications are
undertakenon an engine,a choicemust be madeas
to the ease of reversibility of the engine changes.
This choice must be based on the availabilityof
alcoholfuelf or all anticipatedvehicleuses,fhe cost
of the engine modifications, and the expertiserequired to make the engine changes.
for increased
fuel
3 . m o d i f y i n gt h e c a r b u r e t i o n
flow,
4 . h e a t i n gt h e a i r - f u e l m i x t u r et o e n s u r et h e
vaporizationof the alcohol,and
5 . u s i n gv a r i o u sm e t h o d st o e n h a n q et h e c o l d s t a r t i n ga b i l i t yo f t h e e n g i n e .
SparkTiming
A s a g e n e r a lr u l et h e s p a r kt i m i n go f a n e n g i n e
m u s tb e a d v a n c e dt o r u n o n e t h a n o l T
. h i s i s d o n et o
p r o v i d et h e e t h a n o lw i t h e n o u g ht i m e t o c o m p l e t e
c o m b u s t i o ns, i n c ee t h a n o lb u r n ss l o w e rt h a n g a s o l i n e .O n e s t u d yr e c o m m e n d e ad d v a n c i n g
thetiming
a p p r o x i m a t e l2yO o( F l o w e r se t a l . ,1 9 7 9 ) .
l n a n o t h e rs t u d y ,d o n e r e c e n t l yi n t h e U n i t e d
States,a 1979 Ford Fiestawas modifiedto run on
e t h a n o l( A D M C o r p . ,1 9 8 0 ) .I n t h i s t e s t t h e i g n i t i o n
timing was changedfrom 12" lo 6' BTC. The
i g n i t i o na l s o w a s r e d u c e do n a f o u r - c y l i n d e r1, . 6
l i t e re n g i n eu s e di n a t e s to n e t h a n o li n B r a z i l( P a u l ,
1979)T
. h e i g n i t i o nt i m e , b e f o r eB T C ,w a s r e d u c e d
in the lattertwo tests becauseof the differencesin
t h e m o d i f i c a t i o ndso n e t o t h e d i f f e r e n et n g i n e s .
T h e s p a r k t i m i n g o f a n e n g i n eo p e r a t i n go n
ethanolcan be set two differentways.A tachometer
c a n b e h o o k e d u p t o t h e e n g i n ea n d t h e t i m i n g
a d j u s t e du n t i l t h e m a x i m u mR P M r e a d i n gi s f o u n d
with the engineon fast idle.Anotherway to set the
t i m i n g i s t o s t a r t w i t h a n a d v a n c ei n t h e i g n i t i o n
. h e n u s ea s t o p
t i m i n g o f 4 ' B T C ( M i n g l e ,1 9 7 9 ) T
watchto determine the time it takesfor the vehicleto
a c c e l e r a t ef r o m 3 0 t o 5 5 m p h i n h i g h g e a r a t f u l l
throttle.This procedureis repeatedin 4o of advance
i n c r e m e n t su n t i l t h e m i n i m u ma c c e l e r a t i o tni m e i s
reached.
F r o m t h e d i f f e r e n tc h a n g e sm a d e i n t h e s p a r k
timing in the tests reviewedand the procedures
usedto set the timing,it can be seenthat thereis no
general rule about setting the spark timing for all
engines using ethanol as a f uel. The correct settlng
of the timing depends on the engine and the other
modificationsdone to the engine. lt must be determined by experiment.
Reversible Modifications
Vacuum Advance
T h e f i r s t t y p e so f e n g i n em o d i f i c a t i o nt h a t w i l l
be discussed are reversible.The cost is a few
h u n d r e dd o l l a r so r l e s sd e p e n d i n go n t h e m o d i f i c a t i o n u n d e r t a k e nA
. s i m p l i e d ,t h e s e m o d i f i c a t i o n s
can be undonewith relativeeaseto permitoperation
o n c o n v e n t i o n af u
l e l s .T h e s em o d i f i c a t i o nisn c l u d e :
1 . c h a n g i n gt h e s p a r kt i m i n g ,
2 . c h a n g i n gt h e v a c u u ma d v a n c e ,
C h a n g i n gt h e s e t t i n go f t h e v a c u u ma d v a n c ei s
a n o t h e r r e v e r s i b l em o d i f i c a t i o nT. h e v a c u u m a d v a n c ea f f e c t st h e f u e l e c o n o m yo f t h e e n g i n eo p e r a t i n go n e t h a n o lF. r o mF i g u r e1 ,( C h u ie t a l . ,1 9 7 9 i)t
i s s h o w nt h a t t h e b e s tf u e l e c o n o m yo n t h e e n g i n e
t e s t e do c c u r s w h e n t h e v a c u u ma d v a n c ei s s e t t o
g i v e a n a d d i t i o n a l1 0 o o f a d v a n c eo v e r t h e i d l e
i g n i t i o nt i m e .
V A C U U MA D V A N C E
2.3 LITER ENGINE
IOO "h ETHANOL
t-? o
PRODUCTION
lrJ
z
<l
BEST ECONOMY
f,
()l
T a b l e3 s h o w st h e s er e s u l t su s i n ga n a r b i t r a r y
s c a l ef o r t h e f l o a tl e v e la t d i f f e r e n R
t P M sa n d o r o o f s
o f e t h a n o l .I n t h i st e s ta n i n c r e a s ei n j e t s i z eo f 1 0 t o
150/o
wds sufficient,but the conclusionreachedwas
that the actualjet sizeneededin the carburetormust
be found by experiment.
Adjusting the carburetor also adjusts the
equivalence
r a t i o ,t h a t i s ,
actual
airlfuel
ratio
stoichiometric air/fuel
ratio.
T h e e q u i v a l e n c er a t i o a f f e c t st h e f u e l e c o n o m y ,
t h e r m a le f f i c i e n c ya n d p o w e ro u t p u to f t h e e n g i n e .
F i g u r e2 ( U n i v e r s i t yo f S a n t a C l a r a ,1 9 7 8 )s h o w s
t h a tt h e f u e le c o n o m yo f a n e n g i n eo p e r a t i n go n 2 0 0
p r o o f e t h a n o li s b e s tw h e n t h e e q u i v a l e n c er a t i oi s
a p p r o x i m a t e l y .w
Sh, i c hi s i n t h el e a nr e g i o nF. i g u r e
3 ( U n i v e r s i t oy f S a n t aC l a r a ,1 9 7 8 )s h o w st h a tt h i si s
a p p r o x i m a t e l yt h e s a m e e q u i v a l e n c er a t i o f o r
m a x i m u mt h e r m a le f f i c i e n c yT. h e p o w e ro u t p u t o f
a n e n gi n e i s a l s og r e a t e rw h e nt h ee q ui v a l e n c er a t i o
i s t h e l e a n r e g i o n ( < 1 0 ) H o w e v e r ,i t s h o u l d b e
noted that running an engineon too lean a mixture
EU E L
E T H A N O LA N DI N D O L E N F
URBAN
E C O N O MSYI M U L A T E D
(
D R I V I N GH O T I 9 7 2 F T P )
CC)
F O R DP t NT 0 ( 2 , 3 O O
?34
INTAKE
VACUUM (KPA)
F i g .1 . - F o r t h e
S le n g i n ue s i n g
, eo p t i m u m
e t h a n oals f u e tl h
isf oundto bebelowtheproducforeconomy
sparkadvance
tion vacuumadvance
overthe full rangeof enginein the
vacuum
thatis related
RPM.
to engine
@ osn ETHANoL
O O E MI N D O L E N E
( ) = M A L O I S T R I E U T II O
NN
OEX
2to
(-l-r
:)
LEAN I
F
(D
Carburelor Modifications
o
In allof the testsreviewedthe enginesrequired
more volume of f uel when operatedon ethanolas
compared to operation on gasollne. The correct
s t o i c h i o m e t r i ca i r - f u e lm i x t u r ef o r e t h a n o l i s 9 : 1 ,
w h i l e t h e c o r r e c t m i x t u r e f o r g a s o l i n ei s 1 4 . 7 : 1
( H u n t ,1 9 7 9 ) T
. h e r e a s o nf o r t h e d i f f e r e n c e si n t h e
ratiosis that ethanolhasa lowerenergycontentper
v o l u m et h a ng a s o l i n e .
The f uel-flow increaseis achievedby modifying
the carburetor.The generalprocedurefor the fuelf l o w i n c r e a s ei s t o e n l a r g et h e c a r b u r e t o rf u e l j e t
d i a m e t e r' 11 / 2 t i m e s .T h i s c a n b e d o n e b y d r i l l i n g
o u t t h eo r i g i n ajle t o r r e p l a c i n gt h ej e t .H o w e v e ro, n e
r e c e n t s t u d y ( E n g l e m a n ,1 9 8 0 )s h o w e d d i f f e r e n t
r e s u l t s .I n u s i n g a s i n g l e - c y l i n d eer n g i n e ,a d j u s t m e n to f t h e c a r b u r e t ofrl o a tw i l l i n c r e a s et h e f l o w o f
e t h a n o l .I n c r e a s e df l o w w a s a c h i e v e db e c a u s eo f
i n c r e a s e dl i q u i d h e a d a s w e l l a s t h e d i f f e r e n c e si n
v a p o r p r e s s u r e s, u r f a c et e n s i o n a n d v i s c o s i t yo f
e t h a n o la s c o m p a r e dt o g a s o l i n e .
o
u
RICH
t90
J
=
y
=
lTO
(c.o23)
z
O
U
-:
U
l5o
l
o.7
o.8
0.9
r.o
E o u t v A L E N c En a r r o Q
F i g . 2 . - T h e f u e l e c o n o m y f o r a nS l e n g i n eu t i l i z i n ge t h a n o li s
higher than one using indolene (a standardgasoline mix)
o v e r a l l t e s t e d e q u i v a l e n c er a t i o s u n d e r s i m u l a t e d u r b a n
d r i v i n gc o n d i t i o n s .
Table 3.-Effect of CarburetorFloat Adiustment on Fuel Flow.
Carb
Float
lndolene
190 Proof
180 Proof
9OORPM
1.0
F u e ll b l h r
A/F
IHP
2.60'1
11.79
3.47
3.404
8.93
4.51
4.291
9.18
4.20
2.0
F u e ll b l h r
A/F
IHP
2.484
12.44
4.93
2.984
10.27
3.91
2.874
10.60
3.45
2.6
F u e ll b / h r
A/F
IHP
2.270
13.50
3.55
2.678
'11.54
(Rough
r u n n i n ga n d
m i s fi r i n g )
2.30
1 , 2 0 0R P M
1.0
F u e ll b / h r
A/F
IHP
2.829
12.72
6.41
4.513
8.09
5.93
4.155
8.50
5.45
2.0
F u e ll b / h r
A/F
IHP
2.516
14.30
6.43
4.105
9.10
5.58
3.863
8.90
7.17
2.6
F u e ll b / h r
A/F
IHP
2.410
14.75
6.43
3.862
9.67
5.79
3.749
9.29
4.78
1 , 5 0 0R P M
1.0
F u e ll b / h r
A/F
IHP
2.996
13.12
6.39
4.947
8.18
6.55
4.884
8.45
6.01
2.0
F u e ll b / h r
A/F
IHP
2.811
14.05
6.50
4.728
8.71
6.33
4.622
9.23
5.67
2.6
F u e ll b / h r
A/F
IHP
2.411
16.47
6.23
5.547
8.97
6.08
4.476
9.53
5.57
can resultin burnt valves.A lot of practicalexperi. u n n i n ga n e n g i n e
e n c ea t t e s t st o t h i s c o n c l u s i o nR
o n a r i c h m i x t u r es t i l l d o e sn o t e l i m i n a t et h e a d v a n t a g eo f e t h a n o lo v e rg a s o l i n ef o r t h e r m a le f f i c i e n c y
a n d e c o n o m ya s s e e ni n F i g u r e s2 a n d 3 .
PreheatingAir-Fuel Mixture
As mentionedpreviously,heatingthe air-ethan o l f u e l m i x t u r e r e q u i r e s2 . 5 t i m e s m o r e h e a t f o r
v a p o r i z a t i o nt h a n d o e s g a s o l i n e .F o r t h i s r e a s o n
some additionalheat may be desirablefor the airf uel mixturebeforeit entersthe cylinder.Two of the
tests reviewedused some additionalheat and two
did not.
In a test performedin 1948,a gasolinet{actor
was modifiedto run on 950/o
ethanol(Meyer,1948).
In this test the exhaust gases were recycled to
providethe extra heat in two differentways. In one
part of the test the recycled exhaust gases were
m i x e dd i r e c t l y w i t ht h e i n t a k ea i r .T h e o t h e rm e t h o d
used was to heat the intake air with the exhaust
t h r o u g h a h e a t e x c h a n g e r .T h i s s e c o n d m e t h o d
seemedto be more satisfactory.
In another test from Brazil the exhaust gases
were also recycled to provide more heat for the
i n t a k ea i r o n a f o u r - c y l i n d e r1, . 6l i t e re n g i n e( P a u l ,
1979). However, in this test it was shown that
--
LEAN
A n o t h e r s i m p l e c o l d - s t a r ts y s t e m h a s b e e n
u s e d .T h i ss y s t e mi ss h o w ni n F i g u r e4 . l t c o n s i s t so f
a s e c o n c i a rgya st a n kf o r g a s o l i n e( t h es t a r t i n gf u e l ) ,
a s e c o n d a r ye l e c t r i cf u e l p u m p ,a n d a t o g g l es w i t c h
to engagethe cold-startsystemand needlevalvesto
c o m p l e t e l ys h u t o f f t h e c o l d - s t a r ts y s t e m .V o l k s w a g e nh a sc o m eu p w i t h a s i m i l a rc o l d - s t a rst y s t e m .
Ir
E X A M P L E O F A D U A L -F U E L S Y S T E M
o
z
U S I N G G A S O L I N EA S T H E C O L D -S T A R T I N GF U E L
U
gto
L
L
U
4.
32
UJ
I
F
o
U
FUEL
FILTER
N€EOLE
VALVE
UAIN FUEL
PUMP
T- JOINT
50
+
(TO POWER)
5 GALLON PROPANE
T A N X ( G A S O L I N €)
F
Q
eza
PINTO 2,3OO
CC ENGINE
M B T S P A R KT I M I N G
2 O O OR P M - W O T
0.6
-
DSR ETHANOL
__-
O E M I N D O L E N E( O . 0 6 )
0.7
0.8
0.9
r.o
ELECTRIC
FUEL PUMP
NEEOLE
VALVE
F i g . 4 . - T h i s i s a d i a g r a mo f a d u a l J u e ls y s t e mu s i n g g a s o l i n e a s a c o l d - s t a r t i n gf u e l . T h e s y s t e m r e q u i r e sa s e p a r a t e
s t o r a g et a n k , f u e l p u m p a n d f u e l f i l t e r .
t.l
E Q U I V A L E N C ER A T I O,
Fig.3.-The indicated thermal efficiency of an Sl engine
u s i n ge t h a n o li s h i g h e rt h a n o n e u s i n g i n d o l e n e( a s t a n d a r d
g a s o l i n e m i x ) o v e r a l l t e s t e d e q u i v a l e n c er a t i o s a t W O T o f
2 , 0 0 0R P M .
p r o b l e m sc a n r e s u l tf r o m e x c e s s i v e l yp r e h e a t i n g
t h e i n t a k ea i r . I n t h e e a r l y t e s t st h e i n t a k ea i r w a s
e x c e s s i v e l yp r e h e a t e d ,c a u s i n g s e v e r e e n g i n e
k n o c k ,r e s u l t i n gi n t h e d e s t r u c t i o n
of the engine.
Other methods that have been used to overc o m e t h e c o l d - s t a r tp r o b l e m i n c l u d eu s i n g a 3 5 0
w a t t r e s i s t a n c eh e a t e r i n t h e i n t a k e m a n i f o l d
( S c h r o c k ,1 9 7 9 ) ;u s i n g e l e c t r i cg l o w p l u g s i n t h e
m a n i f o l d( H u n t ,1 9 7 9 ) o; r u s i n ga n e l e c t r i cs c r e e n
g r i d b e t w e e nt h e c a r b u r e t o a
r n d i n t a k em a n i f o l dt o
h e a t t h e a i r - f u e l m i x t u r e ( H i l l , 1 9 8 0 ) .T h i s l a s t
s y s t e mi s s h o w n i n F i g u r e5 . W h e n e v e rc o l d - s t a r t
p r o b l e m sa r e e n c o u n t e r e dt,h e d r i v e rt u r n s o n t h e
k e yf o r 3 0 s e c o n d st o l e tt h e g r i d w a r m u p .T h e nt h e
car is startedas usual.
Cold Start Modification
S C R E E N - G R I DW A R M U P S Y S T E M
O n eo f t h em a i np r o b l e m si n u s i n ge t h a n oiln a n
e n g i n ei s l o w t e m p e r a t u r eT.h i sp r o b l e ma r i s e s f r o m
t h e f a c t t h a t e t h a n o lr e o u i r e sm o r e h e a tf o r v a o o r i zationthan gasoline.Saturafedethanolvaporsare
too lean to ignite below 50"F and starting problems
becomesignificant below 40" F (Keller,1979).
T h e c o l d - s t a r to r o b l e m w i t h e t h a n o l c a n b e
o v e r c o m ei n s e v e r adl i f f e r e n w
t a y s .F i r s ti s t h e u s e
o f a d d i t i v e sI .n o n e t e s ti t w a s f o u n d t h atth ea d d i t i o n
o f 1 0 0 /goa s o l i n et o 2 0 0 p r o o f e t h a n o le x t e n d e dt h e
c o l d - s t a r ta b i l i t y f r o m t h e o r i g i n a l4 0 o F d o w n t o
t h a tr e p o r t e d l y
3 2 " F ( C h u i ,1 9 7 9 )A. n o t h e ra d d i t i v e
h a s g o o d r e s u l t si n o v e r c o m i n gc o l d s t a r t si s e t h e r
( K e l l e r ,1 9 7 9 ) .T h e r e i s c o m m e r c i a l l ya v a i l a b l ea n
e t h e r i n j e c t i o ns y s t e m f o r d i e s e l e n g i n e s ( H i l l ,
19 8 0 ) .
SCREEN GRIO
PLAT€
CARAURETOR
SCAEEN GRIO
PLATE
F i g . 5 . - T h i s i s a d i a g r a m o f a c o l d - s t a r ts y s t e m t h a t u s e s a
g r i d o f h e a t e rw i r e t o h e a t t h e a i r J u e l m i x t u r e a f t e r i t l e a v e s
t h e c a r b u r e t o ra n d b e f o r e e n t e r i n ot h e i n t a k e m a n i f o l d .
Another problem encountered with ethanol at
very high temperaturesvvasvapor lock. ln one study
it was f ound that vaporlock in the f uel pump became
a problem at temperaturesabove 173"F (Keller,
1979).
I rreversible Modif ications
are onesthat
Modificationsthat are irreversible
are hard to remove. They also are usually more
expensive,require more expertise,and can be very
hazardouswhen the engine fails. Modificationsin
t h i s c a t e g o r yi n c l u d e :
1 . c a m s h a f ct h a n g e ,
, nd
2 . i n c r e a s i n tgh ee n g i n ec o m p r e s s i o rna t i o a
3. using turbochargersor superchargers.
CamshaftChange
I n t h e s t u d y o n t h e 1 9 7 9 F o r d F i e s t a( A D M
t a sc h a n g e dA
. ccording
C o r p . ,1 9 8 0 )t h e c a m s h a fw
t o t h e s t u d yt h i sw a sd o n et o p r o v i d em o r el o w R P M
torque,easierstartingand betterf uel economy.The
d e t a i l so f t h i s c h a n g ea n d t h e o t h e r m o d i f i c a t i o n s
made are shown in Table4.
Table 4.-1979 Ford FiestaSpecifications.
Original
Modified
P r i m a r yF u e l
Unleaded
Gasoline
Ethyl
Alcohol-
Bore
Stroke
T o t a lC u b i c I n c h
3.188
3.056
97.6(1,600cc)
3.000
3.056
86.4
(1,416cc)
Compression
Ratio
C a mT i m i n g
Intake:
Open
Close
Exhaust
Open
Close
l g n i t i o nT i m i n g
(static)
8.6:1
29" (BeforeTDC)
63' (After BDC)
7 1 " ( B e f o r eB D C )
2 1 " ( A f t e rT D C )
' 1 2 "( B e f o r e
TDC)
12.5:1
16"
540
540
16"
c y l i n d e rh a s 1 2 1o f o r c o m b u s t i o na n d e x p a n s i o nt o
t a k e p l a c e ,w h i l e t h e e n g i n e m o d i f i e dt o r u n o n
e t h a n o lh a d 1 3 2 ' f o r c o m b u s t i o na n d e x p a n s i o nt o
take place.
Changein CompressionRatio
In all of the tests reviewed,the compression
ratio was increasedto take advantageof the high
octane rating of ethanol to produce more power.
One study suggestedincreasingthe compression
r a t i ot o s o m e w h e r eb e t w e e n1 0 t o 1 5 : 1( F l o w e r se t
al.. 1979).Two of the studiesreviewedf ollowedthis
r e c o m m e n d a t i o nT. h e s t u d y o n t h e F o r d F i e s t a
( A D MC o r p . ,1 9 8 0 )i n c r e a s e tdh e c o m p r e s s i o nr a t i o
, 979)
s t u d y( P a u l 1
f r o m 8 . 6 : 1t o 1 2 . 5 : .1T h e B r a z i l i a n
'l
.2:1
1
.'1
.
to
increasedcompressionratio trom 7
performed
the
tractor
in
1948
The study
on
( M e y e r e ta l . ,1 9 4 8 )d i d n o t f o l l o w t h i sr e c o m m e n d a tion. Rather,the compressionratio was increased
. h e r e a s o nf o r t h i s r e l a t i v e l y
f r o m 6 . 4 : ' 1t o 7 . 3 5 : 1 T
l o w e r c o m p r e s s i o nr a t i o w a s t h a t a l l e n g i n ec o m pressionratios at that time were much lower than
those of today.
The comoressionratiocan be increasedseveral
d i f f e r e n tw a y s . T h e y i n c l u d e i n s t a l l i n gd i f f e r e n t
p i s t o n s ,s h a v i n gt h e h e a d o r u s i n g a t h i n n e rh e a d
g a s k e t .E v e nt h o u g h s o m e o f t h e s em o d i f i c a t i o n s
a r e e a s ya n d i n e x p e n s i vteo d o , o n e t h i n g m u s t b e
emphasized.The increasein compresslonratiocan
damageor even destroy an engine if the other parts
of the engine are not strong enough to handle the
increasedpower or cylinder pressures.
A l l o f t h e t e s t sm e n t i o n e dp r e v i o u s l yi n c r e a s e d
the compressionratioto takeadvantageof ethanol's
h i g h o c t a n er a t i n gt o i n c r e a s et h e p o w e ro u t p u to f
t h e e n g i n e .A n o t h e rw a y t o t a k e a d v a n t a g eo f t h e
h i g h o c t a n er a t i n go f e t h a n o lt o i n c r e a s et h e p o w e r
o u t p u t o f t h e e n g i n e i s t o r a i s et h e c o m p r e s s i o n
p r e s s u r eo f t h e e n g i n e b y t u r b o c h a r g i n gT. a b l e 5
s h o w s t h e t h e o r e t i c a le q u i v a l e n tc o m p r e s s i o n
r a t i o s f o r d i f f e r e n ti n c r e a s e si n t h e a i r p r e s s u r e
( G o e r i n g1
, 979).
Table 5.-EquivalentCompressionRatiosof Tu rbochargedEngine.
o-
.180proof(900/o
10o/o
water)
or 200proofethyl
ethylalcohol:
alcohol.
Otherratiosmavalsobetried.
I t i s i n t e r e s t i n gt o n o t e t h a t e v e n t h o u g h t h e
i g n i t i o nt i m i n gw a s r e t a r d e di n t h i st e s t ,t h e r ei s s t i l l
m o r e t i m e f o r c o m b u s t i o nt o t a k e p l a c ew i t h t h e
e t h a n o lT
. h i s e x t r at i m e i s n e e d e db e c a u s ee t h a n o l
b u r n s s l o w e r t h a n g a s o l i n e .T h e o r i g i n a l e n g i n e
Actual
compression
ratio
7
8
o
10
11
12
Equivalentcompressionratio
at boost pressureof:
5 psi
1 0p s i
1 5p s i
8.8
10.0
11.3
12.5
13.8
10.4
11.9
13.4
14.9
16.4
17.9
12.0
13.7
15.5
17.2
18.9
20.6
16n
A t u r b o c h a r g e ru s e se x h a u s tg a s e st o d r i v e a
t u r b i n e c o n n e c t e dt o a n o t h e rt u r b i n e t h a t f o r c e s
o u t s i d ea i r t h r o u g h t h e c a r b u r e t o rT
. he air that is
f o r c e dt h r o u g ht h e c a r b u r e t ocr a u s e sa n i n c r e a s ei n
t h e c o m b u s t i o np r e s s u r e .O n e d r a w b a c ko f t h e
t u r b o c h a r g e ri s t h a t t h e e x h a u s t d o e s n o t h a v e
e n o u g hp o w e rt o e f f e c t i v e l yr u n t h e s y s t e mu n t i l a
r e l a t i v e l hy i g he n g i n eR P Mi s r e a c h e du, s u a l l y2 , 5 0 0
t o 3 , 0 0 0R P M ( L y n c h ,1 9 7 9 ) .
S u p e r c h a r g i n go v e r c o m e st h e t u r b o c h a r g e r
drawback.A superchargeroperateson the same
p r i n c i p l ea s a t u r b o c h a r g e rb u t i n s t e a do f b e i n g
d r i v e nb y t h e e x h a u s tg a s e s ,i t r u n s o f f t h e e n g i n e
u s i n g a b e l t - d r i v e m e c h a n i s m .T h e r e f o r e , t h e
superchargeroperatesat all RPM levels.
T h e r ea r ed r a w b a c k si n u s i n ga t u r b o c h a r g eor r
nressure
s u p e r c h a r g et ro i n c r e a s et h e c o m p r e s s i o p
i n o r d e rt o i n c r e a s ep o w e r .O n e i s t h e c o s t .T h e k i t s
c u r r e n t l y a v a i l a b l ec o m m e r c i a l l yr a n g e i n p r i c e
. h i s m a k e st h e
f r o m $ 6 0 0t o $ 1 , 2 0 0( L y n c h ,1 9 7 9 ) T
t u r b o c h a r g eor r s u p e r c h a r g ear m a j o r i n v e s t m e n t .
T h e o t h e r d r a w b a c k so f t h e s e u n i t s a r e m e c h a n i c a lT
. h e i n c r e a s ei n c y l i n d e rp r e s s u r ed u r i n g
c o m b u s t i o nm a y c a u s e i n c r e a s e dw e a r o n m a n y
e n g i n ep a r t s .H o w e v e r i, n o n e t e s t p e r f o r m e do n a
f o u r - c y l i n d eer n g i n e i, t w a sf o u n dt h a ta s l o n ga st h e
pressureincreasewas kept moderate(overallpressure of 55 to 60 bars) no harm was done to the
b e a r i n g sp, u s h r o d so r c r a n k s h a f(t S p i n d l e r1, 9 7 8 ) .
In addition to the increasedpressure there is an
increasein the heat neededto be dissipatedfrom
t h e e n g i n e .T h e t e s t m e n t i o n e dp r e v i o u s l y( S p i n d l e r ,1 9 7 8 )u s e da s p e c i a ls, t e e lc y l i n d e rh e a dg a s k e t ,
increasedthe valvestemclearanceto avoid bu rnt o r
s t i c k i n gv a l v e sa, n d m o d i f i e dt h e c o o l i n gs y s t e mt o
a v o i dp r o b l e m sw i t h t h e c y l i n d e rh e a d c r a c k i n g .l t
h a sa l s ob e e nf o u n d t h a t u s i n gb r o n z ev a l v eg u i d e s
o v e r c a m et h e v a l v ep r o b l e m s( L y n c h ,1 9 7 9 ) .
T h e h i g h a m o u n t o f h e a t d i s s i p a t e df r o m t h e
e x h a u s tm a n i f o l da l s o c a u s e dp r o b l e m s( S p i n d l e r ,
1 9 7 8 ) .I n i t i a l l yt h e i n c r e a s ei n h e a tc a u s e db o t h t h e
e x h a u s tm a n i fo l d a n dt h e t u b i n gu s e dt o r e c y c l et h e
exhaustto crack. This problem was overcomeby
m o d i f y i n gt h e e x h a u s tm a n i f o l da n d t u b i n g .E v e n
t h o u g ht h e r ea r e s e v e r am
l e c h a n i c apl r o b l e m sw i t h
u s i n gt u r b o c h a r g e rosr s u p e r c h a r g e r tsh, e y a l l c a n
be overcomeas they were in this test.
O n e f a c t w o r t h m e n t i o n i n gi s t h a tt h e f u e l u s e d
i n t h e p r e v i o u s l ym e n t i o n e dt e s t w a s g a s o l i n e .
F i g u r e6 ( P y r e ,1 9 3 7 )s h o w st h a ta l c o h o l( 1 9 5p r o o f )
as compared to gasoline,gives more heat to the
e x h a u s ta n d l e s sh e a tt o t h e c y l i n d e rw a l l s( c o o l i n g
w a t e r )w h e n r u n i n a n e n g i n ew i t h o u tt u r b o c h a r g i n g
o r s u p e r c h a r g i n gF. r o mt h i s i t m i g h t b e c o n c l u d e d
t h a t o p e r a t i o no n a l c o h o lm i g h td e c r e a s et h e p r o b -
10
lems caused by the increasedheat entering the
e n g i n e ,w h i l e i n c r e a s i n gt h e p r o b l e m sc a u s e db y
the increasedheat leavingthe engine.
ALCOHOL
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E Q U I V A L E N C ER A T I O , O
l r
F i g .6 . - H e a t d i s t r i b u t i o ni n a n S l e n g i n eu s i n ge t h a n o o
g a s o l i n eA. h i g h e rp e r c e n t a goef h e a ti s f o u n di n t h ee x h a u s t
a n d i n e n g i n eh o r s e p o w e b
r ,u t a l o w e rp e r c e n t a goef h e a ti s
f o u n d i n c o o l i n gw a t e rw h e n f u e l e dw i t h e t h a n o lo v e r a l l
e o u i v a l e n crea t i o s .
A g a i n , a s w i t h t h e c o m p r e s s i o n r a t i o i n c r e a s e ,i f
the parts of the engine are not strong enough to
handle the increased power, the engine may be
damaged or destroyed.
M echanicalModificationsRequi r ed
for Use of Ethanolas Fuel in a
DieselEngine
A s m e n t i o n e db e f o r e ,t h e d i e s e le n g i n ei s n o t
w e l l - s u i t e dt o t h e u s e o f e t h a n o l .B u t , f o u r b a s i c
l n g i n eh a v e
a p p r o a c h e st o u s i n ge t h a n o li n a d i e s e e
b e e nf o u n d :
1. c o n v e r td i e s e el n g i n et o a h i g hc o m p r e s s i o n ,
s p a r ki g n i t i o ne n g i n e ,
2. modifythe dieselto toleratestraightethanol
injection,
3. carburetthe ethanol,and
4 . u s ed u a l i n j e c t i o no f e t h a n o la n d d i e s e fl u e l .
s o o n b e c o m m e r c i a l l ya v a i l a b l eb y M & W G e a r
C o m p a n y ,G i b s o n C i t y , l l l i n o i s .T h i s s y s t e mu s e s
t h e t u r b o c h a r g e rb o o s t t o p r e s s u r i z et h e a l c o h o l
f u e l t a n k i n o r d e rt o m e t e rt h e f u e l a s a f u n c t i o no f
e n g i n e l o a d .T h e a l c o h o lf u e l i s n o t a d d e d a t l o w
l o a d .R e s e a r c hh a s i n d i c a t e dr e d u c e de n g i n ee f f i c i e n c ya t l i g h tl o a d ,b u t i n c r e a s e tdh e r m a el f f i c i e n c y
o v e rd i e s e fl u e l m a y o c c u ro n l y a t h e a v yl o a d i n g .I n
g e n e r a tl h o u g h ,i t s h o u l db e a s s u m e dt h a t c a r b u r e t i o n o f a l c o h o li n t o a d i e s e le n g i n er e p l a c e sd i e s e l
f u e l o n a n e q u a lh e a tc o n t e n tb a s i sw i t h n o c h a n g e
i n e f f i c i e n c y( S c h r o c k 1, 9 7 9 ) .
T h e r ew a s a d e v e l o p m e not f a n a l t e r n a t i v de i e d u r i n gW W l l i n w h i c h
s e l e n g i n ew i t hd u a li n j e c t i o n
t h e m a i nf u e l ,a l o wc e t a n er a t e df u e l ,i s i n j e c t e dw i t h
t h e a i r i n t o a d i e s e la n d a p i l o t f u e l ,a h i g h c e t a n e
f u e l , i s i n j e c t e dn e a r t h e e n d o f t h e c o m p r e s s i o n
cycle that ignites,from compressionheat,the total
f u e l m i x t ur e ( B r oe t a | . , 1 9 7 7 )S. e eF i gu r e7 . T h e l o w
c e t a n em a i n f u e l m a k e su p a p p r o x i m a t e l 7y 0 p e r cent of the total fuel energy.Researcheffortshave
u t i l i z e do n l y 2 0 0 p r o o f e t h a n o la s a m a i n f u e l , b u t
t h e r es e e m st o b e n o l i m i t a t i o no f u s i n ga n e t h a n o l
f uel that has a lower proof.
O n e e n g i n et h a t l e n d si t s e l ft o t h i s c o n v e r s i o n
t o s p a r ki g n i t i o ni s t h e 8 5 5C u m m i n sD i e s e lE n g i n e
( S c h r o c k ,1 9 7 9 ) .T h e a r e a st h a t r e q u i r em o d i f i c a t i o n i n c l u d e t h e p i s t o n s ,h e a d a s s e m b l y ,i n t a k e
m a n i f o l di g n i t i o ns y s t e m c, a r b u r e t oar n d g o v e r n o r .
P a r t s a r e a v a i l a b l ef o r t h e c o n v e r s i o n ,b u t t h e
e s t i m a t e dm i n i m u m c o s t f o r t h e m o d i f i c a t i o n si s
$3,000.
f o r t h e m i l i t a r yi,s
A m u l t i f u e l e n g i n ed,e v e l o p e d
d e s i g n e dt o f u n c t i o nu s i n gf u e l sr a n g i n gf r o md i e s e l
o i l t o l o w o c t a n ec o m b a tg a s o l i n eT. h e M A N D i e s e l
( a l s ok n o w na s t h e M e u r e ro r W h i s p e rd i e s e l )h a sa
u n i q u e c o m b u s t i o nc h a m b e r d e s i g n t o f u n c t i o n
s m o o t h l y u s i n g l o w c e t a n ef u e l s a n d l o w o c t a n e
g a s o l i n e( S c h r o c k1, 9 7 9 )T. h i sd i e s e el n g i n ed e s i g n
c o u l db e t h e m o s tt o l e r a n ot f m a n u f a c t u r eedn g i n e s
t o u s e e t h a n o lw i t h o u t m o d i f i c a t i o nT. h i s e n g i n e
was offered for limited agriculture use by InternationalHarvesterand Whitein the last10 years,but
i t i s n o t p r e s e n t l ya v a i l a b l e .
l n g i n e si s
A n o t h e rw a y t o u s ee t h a n o li n d i e s e e
to carburee
t t h a n o li n t o t h e a i r i n t a k ei n f r o n t o f t h e
t u r b o c h a r g e (r S c h r o c k ,1 9 7 9 ) .A k i t t o d o t h i s w i l l
D I R E C T I N J E C T I O ND I E S E LE N G I N E
U S I N G A L C O H O LA N O P I L O T I N J E C T I O N
Compar isonof EnginePer for m anc e
on Ethanoland GonventionalF uel s
FuelEconomy
E L E C T R O N I CF U E
I N . ' E C T I O N F OR
LIOUID FUEL
The volumetric fuel economy of S/ englnes
using ethanolas a fuel is not as good as that of the
same engines operating on gasoline. The maior
reason for this is that ethanol does not contain as
much energy per unit volume or per unit weight as
gasoline.Pure ethanol (200proof) contains650/o
of
t h e e n e r g yp e r u n i t v o l u m ea n d 6 1 %o f t h e e n e r g y
per unit weight when comparedto gasoline
( S c h r o c k , 1 9 7 9 ) .T h e r e f o r e ,w h e n c o m p a r e d t o
g a s o l i n em
, o r e e t h a n o li s r e q u i r e dt o d o t h e s a m e
work in an engine.
T h e a b o v e i s c o n f i r m e di n a l l o f t h e s t u d i e s
reviewed.But differenttests give different results
d e p e n d i n go n t h e e n g i n ea n d t h e m o d i f i c a t i o n os f
the engine.ln a test performedinBrazil,it wasfound
t h a t v o l u m e t r i cf u e l c o n s u m p t i o nw a s 5 t o 1 0 0 / o
h i g h e rf o r 2 0 0 p r o o f e t h a n o la s c o m p a r e dt o g a s o l i n e ( M u e l l e r ,1 9 7 8 ) .A n o t h e r t e s t , o f w h i c h t h e
r e s u l t sa r es h o w ni n F i g u r e8 ( M u e l l e r1, 9 7 8 )s, h o w s
t h a tt h e s p e c i ifc e n e r g yc o n s u m p t i o ni n t e r m so f B t u
p e r g a l l o ni s a b o u t1 2 o /loo w e ri n a l o w c o m p r e s s i o n
e n g i n ea n d 1 5 0 /l o w e ri n a h i g hc o m p r e s s i o e
nngine
. his implies
f o r e t h a n o la s c o m p a r e dt o g a s o l i n e T
t h a t h i g h e r c o m p r e s s i o nr a t i o e n g i n e sa r e m o r e
'190
e f f i c i e n ti n u s i n g t h e h i g h e r o c t a n e v a l u e o f
p r o o fe t h a n o l .
I NTAKE
EXHAUST
ILOT FUEL
INJECTION
N O Z ZL E
F i g .7 . - D u a l i n j e c t o r fsu e la d i e s e l e n g i n eO.n ei n j e c t opr u t s
i n 3 0 0 /oof f u e le n e r g ya s a h i g hc e t a n ef u e lt h a ti g n i t e sd u e t o
h e a to f c o m p r e s s i o na,n d t h e na s e c o n di n j e c t o rp u t si n t h e
r e m a i n d eor f f u e le n e r g ya s l o w c e t a n ef u e l .
11
Table 6.-Fuel Efficiencyol a Six-CylinderEngine.
COMPARATIVE
SPECIFICENERGY
USING
CONSUMPTION
OF ENGINES
N E A T E T H A N O L ( 5 % W A T E R)
AND GASOLINE
I
Gasoline
(Original
Engine)
F u e l ,g a l / h r
( a tm a x i m u m
power)
HP - h r / g a l
Thermal
E ff i c i e n c y ,
+
lrJ
z
=
U
LC R
HCR
(t
(D
o/o
E t h a n o lP r o o f
164
186
200
7.44
7.4
T.IJ
/.o
6.3
8.82
4.3
11.7
27
260/o
25o/o
27olo
lrj
z
o
an
sion ratio tor 192 proof ethanol showed an even
greaterpower increase.The maximumhorsepower
i n c r e a s e d1 8 . 7 o / 0
w,h i l e t h e m a x i m u m t o r q u e i n on ethanol operation (Paul, 1979).
creased20.5o/o
T h e i n c r e a s ei n p o w e rg a i n e df r o me t h a n o li ss h o w n
i n F i g u r e9 ( H u n t ,1 9 8 0 )a s a f u n c t i o no f R P M .I n t h i s
t e s tt h e s i x - c y l i n d eer n g i n er u n n i n go n e t h a n o lh a d
the compressionratioincreasedfrom 7.5:1to 8.45:1,
a reworkedcarburetoranda heatedintakemanifold.
(9
=
o
CE
lt
-l
lrJ
o
z
(J
-l
LCR. LOW COMPRESSIOR
NATIO ENGINE
H C R .H I G HC O M P R E S S I O
RN
ATIO ENGINE
F i g . 8 . - T h e c o m p a r i s o no f t h e s p e c i fi c e n e r g yc o n s u m p t i o n
o f h i g h c o m p r e s s i o na n d l o w c o m p r e s s i o nS l e n g i n e ss h o w
that the ethanolJueled engines require less energy than
g a s o l i n e -uf e l e d e n g i n e s .T h e h i g h - c o m p r e s s i o ne n g i n e r e q u i r e s l e s s e n e r g y t h a n t h e l o w - c o m p r e s s i o ng a s o l i n e
e n gi n e .
As the proofof ethanolincreasesthe volumetric
f u e l e c o n o m yi m p r o v e sA. s e x p e c t e dt,h i s i s d u e t o
the fact that increasingthe proof increasesthe
v o l u m e t r i ce n e r g yc o n t e n to f t h e e t h a n o l .T a b l e 6
( H u n t ,19 8 0 )i n d i c a t e st h i si n t e r m so f t h e r a n g eo f a
v e h i c l eo p e r a t i n go n e t h a n o la s c o m p a r e dt o g a s o l i n e .A f u e l t a n kt h a tw o u l dc a r r ya v e h i c l e2 0 0 m i l e s
o n g a s o l i n ew o u l d g o 1 3 5 m i l e s o n 2 0 0 p r o o f
e t h a n o l 9, 5 m i l e so n 1 6 0p r o o fe t h a n o a
l n d6 0 m i l e s
o n 1 2 0p r o o fe t h a n o l( S c h r o c k 1, 9 7 9 ) .
Power Output
The power output of ethanol was greaterin all
of the testsreviewedwhen comparedto gasoline.
O n e s t u d y ,w h i c h c o m p a r e d1 9 0p r o o fe t h a n o la n d
gasoline,showeda 30/o
increasein poweroutput for
ethanol at the same compressionratio (Schrock,
19 7 9 ) .
Another study that used 7.2:1 compression
r a t i of o r g a s o l i n eo p e r a t i o na n d a n 1 1 : 1c o m p r e s -
12
il
tt
r,7oo RATEDlsOO
tpOO
R E V O L U T I O N SP E R M I N U T E
C Y L I N D E R -2 4 0 C U B I CI N C H E S )
F i g . 9 . - T h e i n d i c a t e dh o r s e p o w e ro f a n S l e n g i n e i n d i c a t e s
t h a t t h e e t h a n o l f u e l e d e n g i n e a t a l l p r o o fs w a s h i g h e r t h a n
t h e g a s o l i n ee n g i n e a t t h e r a t e d R P M .
F i g u r e 1 0 ( U n i v e r s i t yo f S a n t a C l a r a , 1 9 7 8 )
s h o w st h e h o r s e p o w ear s a f u n c t i o no f e q u i v a l e n c e
r a t i o f o r b o t h g a s o l i n e a n d c o m m e r c i a lg r a d e
e t h a n o l .T h e e n g i n eo p e r a t e do n e t h a n o lu s e d t h e
D e r e s s e r a t oI rn d u c t i o nS y s t e m .E t h a n o lf u e l g a v e
g r e a t e rb r a k e h o r s e p o w e ri n c o m p a r i s o nt o i n d o l e n e( a s t a n d a r dg a s o l i n e ) .
+l
LEAN
tr
g
o
-)
I
R I CH
4s
.L
lrJ
(t,
(E
o
-40
UJ
I
a t e d w i t h p r o l o n g e di n h a l a t i o ni n c l u d ec o u g h i n g ,
eye irritationand headaches.
T h e s t o r a g eo f e t h a n o lm u s t b e h a n d l e dd i f f e r e n t l y fr o m t h a to f g a s o l i n eF. o r m a x i m u ms a f e t ya n d
t o r e d u c el o s s e sd u r i n gs t o r a g ee, t h a n o ls h o u l db e
s t o r e d i n w h i t e t a n k s i n a s h a d e da r e a .T h e t a n k s
relief
s h o u l d b e e q u i p p e dw i t h p r e s s u r e - v a c u u m
f i ll e rc u p s .N o r u b b e rh o s e so r s e a l ss h o u l db e u s e d
w i t h i nt h e s y s t e mi n o r d e rt o a v o i dl e a k sc a u s e db y
t h e d e t e r i o r a t i o no f r u b b e r w h e n i n c o n t a c tw i t h
e t h a n o l( R i d e re t a l . ,1 9 7 9 ) .
E t h a n o il s t o t a l l yd i f f e r e n ft r o m g a s o l i n ei n t h a t
i t d o e s m i x w i t h w a t e r . F o r t h i s r e a s o ne t h a n o l
s h o u l dn e v e rb e s t o r e di n a t a n k w h e r et h e r ei s a n y
w a t e ro r t h e r ee x i s t sa p o s s i b i l i t yo f w a t e rc o m i n g
i n t o c o n t a c t w i t h t h e e t h a n o l .T h i s a l s o i n c l u d e s
p r o l o n g e de x p o s u r et o h i g h h u m i d i t ya i r .
Ethanolburnswith a nearlyinvisibleblue flame,
while gasoline or diesel burns with a highly visible
yellow or orange tlame. Sometimesthe only det e c t a b l ef e a t u r e o f b u r n i n o e t h a n o l i s t h e h e a t
waves.
E
(D
35
COMPARATIVEPOWER OUTPUT
O F E N G I N E SU S I N G N E A T E T H A N O L
( 5 % W A T E R )A N O G A S O L I N E
:g
0.70
lrJ
z.
J
tlJ
UI
6
F i g . 1 o . - T h e b r a k e h o r s e p o w e ro f a n S l e n g i n e f u e l e d w i t h
e t h a n o l i s h i g h e r t h a n e n g i n e sf u e l e d w i t h i n d o l e n eo v e r t h e
tested eouivalence ratios at 2.000 RPM.
U
=
.J'
, 9 7 8 )t h e p e r c e n t a g e
I n F i g u r e1 1 ( M u e l l e r 1
p o w e r i n c r e a s e sa r e s h o w n f o r b o t h a h i g h c o m p r e s s i o nr a t i oe n g i n ea n d a l o w c o m p r e s s i o nr a t i o
e n g i n eo p e r a t i n go n 1 9 0p r o o fe t h a n o al s c o m p a r e d
. h e e n g i n eo p e r a t i n go n e t h a n o lh a d
t o g a s o l i n eT
m o d i f i c a t i o n so n t h e c a r b u r e t o r a n d i g n i t i o n
system.
Sa f e t yi n H a n d l i n gE th a n o l
o
E
L
u
z
o
LCR
HCR
NA T I OE N G I N E
L C R . L O W C O M P R E S S I OR
H C R ' H I G H C O M P R E S S I ORNA T I OE N G I N E
E t h a n o li s n o t h i g h l y t o x i c b u t s o m e d i s c o m forts havebeen known to occur if the fumesare
i n h a l e df o r a l o n g p e r i o do f t i m e i n a p o o r l y v e n t i . h e d i s c o m f o r t sa s s o c i l a t e da r e a ( M u e l l e r1, 9 7 8 ) T
F i g . 1 1 . - T h e c o m p a r a t i v ep o w e r o u t p u t o f a h i g h a n d a l o w
c o m p r e s s i o ne n g i n e f u e l e dw i t h e t h a n o l i s h i g h e r t h a n w h e n
f u e l e dw i t h g a s o l i n e .
'13
Tabfe 7.-NFPS Hazard ldentificationSignals.
Health
Methanol
Fire
Reactivity
1a
Ethanol
0
Gasoline
a0
safe
E x t i n g u i s hA g e n t
a l c o h o lf o a m ,C O zo r d r y
chemical
water.alcoholfoam, CO2or
dry chemical
f o a m ,C O zo r d r y c h e m i c a l
4
severelyhazardous
E t h a n o al l s od i f f e r sf r o m g a s o l i n ei n t h e k i n d o f
e x t i n g u i s h i nagg e n tt h a tm a y b e u s e do n i t i n c a s eo f
f ire. Listed in Table 7 are the NFPShazardidentific a t i o ns i g n a l sf o r t w o t y p e so f a l c o h o la n d g a s o l i n e
( P a u l ,1 9 7 9 ) .
Deterioration
of Materiatsin
Contactwith Ethanol
Ethanol has been found to be corrosive to
severalmaterialsthat are exposedwithin the engine
or fuel system of the vehicle. ln the fuel system,
ethanol has been found to be corroslve to polya'
mide filter housings, polyurethane and polyester
bonded fiberglass(Schrock, 1979).For this reason
it is recommendedthat allhosesand the f uel pump
diaphragm be made of neoprene rubber, a material
compatiblewith ethanol(Nerpel,1980).
Ethanol is also corrosive to metals,such as
s t e e l ,a l u m i n u ma n d c o p p e r .T h e e x t e n tt o w h i c h i t
corrodes these materials can be shown by an
exampleusing the relativecorrosionratesof these
m e t a l sw h e n i m m e r s e di n 2 0 0p r o o fe t h a n o al t r o o m
et al., 1980).Assuming
temperature(Persiantseva
a n 8 - g a u g em e t a l( t h i c k n e s os f . 1 2 8i n c h e s )u s e di n
a storagetank or a pieceof tubing,it would take the
ethanol32 yearsto completelypenetratethe steel,
3 1. 17 y e a r sf o r t h ea l u m i n u ma n d 1 8 2 . 9y e a r sf o r t h e
copper.
T h e p r o o f o f t h e e t h a n o la l s o i n f l u e n c e st h e
corrosion rates of these metals in ethanol. lf the
metalsare immersedin 90 proof ethanolinsteadof
the 200 proof ethanol, the steel's corrosion rate
would increase2.3times,the copperwould increase
1 . 6 t i m e s ,a n d t h e a l u m i n u mw o u l d d e c r e a s e4 . 1
t i m e s( P e r s i a n t s e veat a l . ,1 9 8 0 ) .
Temperaturealso affectsthe corrosionrate of
metals.lf the temperatureincreasesfrom 80'F to
280"F the corrosionratefor steelin ethanolgoes up
f r o m . 0 0 4i n c h e sp e r y e a rt o . 0 5i n c h e sp e r y e a r ,a n
i n c r e a s eo f 1 2 . 5t i m e s( P e r r y ,19 7 3 ) .
I t s h o u l db e n o t e dt h a tt h e r ei s a n o t h e rp r o b l e m
with having aluminum in contact with ethanol.
When ethanol and water come into contact with
a l u m i n u mt h e y p i c k u p a l u m i n u mo x i d ef o r m i n ga
m i l k y w h i t e s l u d g e( S c h n e i d e r1, 9 7 9 ) .l t i s r e c o m m e n d e d t h a t a n y a l u m i n u mt h a t m i g h t c o m e i n
contact with the ethanol be replacedbecausethe
s l u d g ec o u l d c l o g f i l t e r sa n d f u e l l i n e s .
Zinc is also incompatible with ethanol. In one
t e s t ,t h e v e h i c l ec o n t a i n e da z i n c - l i n e dg a st a n kt h a t
h a d t o b e r e p l a c e dw i t h a s t a i n l e s s t e e lt a n k ( H i l l ,
1 9 8 0 )S
. t a i n l e s s s t e ei sl k n o w nt o b e h i g h l yr e s i s t a n t
to corrosionby ethanoleven at high temperatures.
A s a c o n s e q u e n c eo f t h e i n c o m p a t a b i l i t i e s
associatedwith ethanol,it is recommendedthat the
f ol lowing areasbe checkedf or compatabiIity before
r u n n i n ga n e n g i n eo n e t h a n o l( F l o w e r se t a l . ,1 9 7 9 ) :
r carburetorfloat,
o carburetorneedleand seat,
o cdrburetorfilter (plasticgasket),
o f u e l f i l t e r( p l a s t i c ) ,
o fuellines,
o f u e l p u m p ( p l a s t i ca n d r u b b e rp a r t s )a n d
o f u e lt a n k .
PollutantEmissionsLevelsof
EnginesUsing Ethanol
There are conflictingreportson the effectsof
e t h a n o lu s e o n t h e e x h a u s te m i s s i o n so f e n g i n e s .
T h e s ec o n f l i c t sr e s u l tm a i n l yf r o m u s i n g d i f f e r e n t
e n g i n e sa n d d i f f e r e n tm e t h o d so f e v a l u a t i n gt h e
e m i s s i o n s .I n T a b l e 8 ( P a u l , 1 9 7 9 ) t h e e x h a u s t
c o m p o s i t i o no f a n e n g i n eo p e r a t i n go n e t h a n o li s
s h o w n .T h e e n g i n eh a d a d i s p l a c e m e notf 2 . 3 l i t e r s
and a modifiedcarburetor.
14
Table 8.-Exhaust Compositionf rom NeatEthanolbyFTIRSand OtherMethods.
Compound
Water
C a r b o nd i o x i d e
C a r b o nm o n o x i d e
Heavyhydrocarbons(Cu+1
N i t r i co x i d e
N i t r o g e nd i o x i d e
N i t r o u so x i d e
N i t r o u sa c i d
H y d r o g e nc y a n i d e
Ammonia
S u l f u rd i o x i d e
Methane
Acetylene
Ethylene
Ethane
Propylene
lsobutane
Formaldehyde
Acetaldehyde
F o r m i ca c i d
Methanol
Ethanol
Total NOX
Total HC
*
FTIRS
A m o u n ta t
4 Hours
(ppm)
1.10.
1.08488.
0.3**
14.4
46.9
0.4
2.4
0.1
0
0.3
8.7*"
4 . 6 "*
26.0
1.8**
0.5**
3.0**
8.8.57.4**
0.6..
7 . 6 **
194.-.
63.7
313.3*.
Error
0.2
0.2
18.4
14.7
0.6
0.6
0.2
0.2
0.4
o.2
0.4
0.2
0.4
0.9
0.4
'1.8
1.8
0.2
1.6
0.2
0.2
o:
A m o u n ta t
26Hours
o.52
1.07
490.
0.
4.0
31.5
0.4
2.2
0
0.1
tl
8.8
AA
26.0
1.7
0.6
e6
7.8
55.6
0.2
6.4
168.
37.6
280.0
o/o
'. ppm carbon
N01 Emissions
Unburned Fuel Emissions
I t w a sf o u n dt h a tN O Xe m i s s i o n w
s e r eg e n e r a l l y
l e s sf o r e t h a n o la s c o m p a r e dt o g a s o l i n eT. h i s h e l d
t r u e e x c e p ti n t h e v e r y l e a n a n d v e r y r i c h r e g i o n s .
F i g u r e1 2 ( U n i v e r s i t yo f S a n t aC l a r a ,1 9 7 8 )p o i n t s
t h i s o u t i n g r a p h i c afl o r m .
T h e a m o u n t b y w h i c h t h e N O y e m i s s i o n sd e crease varies between tests. One test reported
r e d u c t i o no f 5 5 t o 6 0 % u s i n g e t h a n o la t t h e s a m e
. n o t h e rt e s t f o u n d
e q u i v a l e n c er a t i o ( P a u l ,1 9 7 9 ) A
that reductionto be 8 to 12 o/oal the same equival e n c er a t i o( U n i v e r s i toy f S a n t aC l a r a ,1 9 7 8 ) .
T h e u n b u r n e df u e l e m i s s i o n sw e r ef o u n dt o b e
. n e t e s tw i t h
h i g h e rf o r e t h a n o lt h a n f o r g a s o l i n e O
t h e s a m ee n g i n e so p e r a t i n ga t t h e s a m ee q u i v a l e n c e
ratio, reportedincreasesof 6 to 25 0/o(Universityof
S a n t aC l a r a , 1 9 7 8I)n. F i g u r e1 3 ( M u e l l e r1, 9 7 8 ) t h i s
i n c r e a s ei s a l s os h o w ne x c e p ti n t h e r i c h r e g i o n .
Aldehyde Emissions
I t s h o u l d b e n o t e d t h a t a t t h e p r e s e n tt i m e
a l d e h y d ee m i s s i o n sa r e n o t f e d e r a l l yr e g u l a t e dB. u t
t h e a l d e h y d ee m i s s i o n sf r o m e t h a n o lo p e r a t i o na r e
m u c h h i g h e rw h e nc o m p a r e dt o o p e r a t i o no n g a s o l i n e .I n o n e t e s t ,w i t h t h e c a r b u r e t o ar n d d i s t r i b u t o r
i ncreasewasf ound (Chu i, 1979).In
modified,a 5Oo/o
F i g u r e1 4 ( U n i v e r s i toy f S a n t aC l a r a ,1 9 7 8 )a l a r g e r
i n c r e a s ei s s h o w n .T h e i n c r e a s es h o w n f r o m t h i s
g r a p h r a n g e sf r o m t h r e e t o s i x t i m e s t h e g a s o l i n e
C O E mi ssi o n s
T h e C O e m i s s i o n s w e rfeo u n dt o b e l o w e r w h e n
. ne test
o p e r a t i n go n e t h a n o lt h a n w i t h g a s o l i n e O
reported that CO emi ssionswere reduced30 to 60 0/o
w h e n o p e r a t i n go n e t h a n o a
l t t h e s a m ee q u i v a l e n c e
ratio (Universityof SantaClara,1978).
15
P I N T O 2 , 3 O OC C E N G I N E
M B T S P A R KT I M I N G
a O O O R P M- W O T
FORDPINTO 2.5 LITER
M B T S P A R KT I M I N G
2 0 0 0 R P M, W o T
DSR ETHANOL
-_-OEMINDOLENE
BASIS
DATA ON PER-CYLINDER
DSR ETHANOL
-__OEM
INDOLENE
r0c
r2.o
CL
(-l
t
I
-
to
E
o
o
I RICH
a
z
o
o
z
LEAN
8.O
6
a
(n
6
I
r
q
u
x
o
z
|r
6.O
J
4.O
U
z
4.
z
o.6
o.7
0.8
o9
LO
t.l
?.o
o.7
E Q U I V A L E N C ER A T I O , ! [
o.8
0.9
t.o
t .I
t.2
E O U I V A L E N C EN A T I O , Q
F i g .1 3 . - T h e u n b u r n e df u e l e m i s s i o nfsr o m a n S l e n g i n e
f u e l e dw i t h e t h a n o la r e e q u i v a l e ntto e n g i n e sf u e l e dw i t h
i n d o l e n eT. h e u n b u r n e df u e le m i s s i o nas r eg r e a t e fro r i n d o l e n ew h e nt h e e q u i v a l e n crea t i oi s h i g h e rt h a n1 . 0 .
Fig. 12.-The nitrogen oxides emitted f rom an Sl engine
f ueled with ethanol and indoleneare nearly equal for all
e q u i v a l e n c er a t i o s e x c e p t i n t h e 0 . 9 t o 1 . 0 r a n g e w h e r e t h e
e t h a n o lf u e l e de n g i n e se m i t c o n s i d e r a b l yl e s s N O y .
o p e r a t i o nv a l u e s O
. n e t e s tr e p o r t e dt h a ta s t a n d a r d
c a t a l y t i cc o n v e r t e rc a n e l i m i n a t et h e p r o b l e m so f
a l d e h y d e m i s s i o n (sH i l l ,1 9 8 0 ) .
O n e p r o b l e mp o i n t e do u t i n t h e e m i s s i o n tse s t s
w a s t h e m a l d i s t r i b u t i obne t w e e nc y l i n d e r s( f a i l u r e
o f f u e l t o d i s t r i b u t ee v e n l ya m o n gc y l i n d e r s r) e s u l t i n g f r o m t h e u s e o f e t h a n o l .l t w a s f o u n d t h a t t h i s
p r o b l e m i n c r e a s e dw i t h i n c r e a s i n gv e h i c l es p e e d
( C h u i ,1 9 7 9 ) T
. h e m a l d i s t r i b u t i ovna r i e dt h e e m i s s i o n sf r o m o n e c y l i n d e rt o t h e n e x t ,b u t i t i s n o t
k n o w nw h a t e f f e c tt h i s o r o b l e mh a s o n o t h e ra r e a s
o f e n g i n eo p e r a t i o no n e t h a n o l .
the ethanol (Rider et al., 1979). Another study
c o n d u c t e dd u r i n g t h e w i n t e r , o n s h o r t t r i p s a n d
stop-and-godriving, reporteda 1800/o
increasein
t h e i r o n w e a r o f t h e e n g i n e p l u s i n c r e a s e do i l
v i s c o s i t ya n d a c i dc o n t e n t .l t w e n to n t o s a yt h a t t h e
p r o b l e m sa r e n o t s e r i o u sa t h i g h e r a m b i e n tt e m peratures(Schrock,1979).
A s m e n t i o n e de a r l i e r ,i n s o m e t e s t st h e i n t a k e
a i r o f t h e e n g i n eu s i n ge t h a n o li s p r e h e a t e dl.t w a s
f o u n d t h a t w h e n t h e i n t a k ea i r w a s h e a t e de x c e s s i v e l ye n g i n ek n o c k o c c u r r e da n d t h e e n g i n ew a s
destroyedT
. h e s t u d y r e c o m m e n d e dk e e p i n gt h e
t e m p e r a t u ro
e f t h e e n g i n ep a r t sb e l o w2 9 0 ' C ( P a u l ,
19 7 9 ) .
A n o t h e rp r o b l e mm e n t i o n e di n o n e p a p e rw a s
t h a t v a l v e r e c e s s i o nm i g h t o c c u r i n o l d e r m o d e l
. his
e n g r n e so p e r a t i n go n e t h a n o l( S c h r o c k1, 9 7 9 )T
p r o b l e mc a n a l s o o c c u r i n o l d e r m o d e l e n g i n e s
o p e r a t i n g o n u n l e a d e d g a s o l i n e .T h e p r o b l e m
occurs becauseof the absenceof tetraethyllead.
N e w m o d e lc a r sa r ee q u i p p e dw i t hv a l v es e a ti n s e r t s
t o e l i m i n a t teh i sp r o b l e ml.f t h i sp r o b l e mo c c ur s i t i s
r e c o m m e n d e dt h a t v a l v es e a t i n s e r t sb e o l a c e di n
E n g i n eD u r a b i l i t y
U si n g E th a n o l
There see/ns to be some conflict between reportson the effectof ethanolon enginedurability.
O n e s t u d y r e p o r t e dn o d o c u m e n t e di n c i d e n c e so f
e n g i n ec o r r o s i o nd u e t o e t h a n o lu s e . l t s t a t e dt h a t
t o e t h a n o l w a sr e a l l y
t h ee n g i n ec o r r o s i o na t t r i b u t e d
t
h
e
a r e s u l to f
d e n a t u r a not r o t h e ra d d i t i v e su s e di n
16
the headsorthat the headsbe replacedwith a newer
model.
Friction and wear characteristicsof various
f u e l s w e r e t e s t ebdy B a i l y e ta l .( 19 7 9 )i n a c c o r d a n c e
with ASTM standards.The lubricationperformance
of ethanol was poorer than dieselfuel, but it was
s u p e r i o rt o g a s o l i n e .
I n d u a l i n j e c t i o nd i e s e le n g i n e s( o n e i n j e c t i n g
b o t h e t h a n o la n d d i e s e lf u e l )t h e p r o b l e mo f h e a v y
k n o c k o c c u r r e dw h e n t h e i n t a k ea i r w a s h e a t e d
excessively.lt was found that at air temperatures
a b o v e 2 0 0 " C t h e e t h a n o l s e l f - i g n i t e dd u r i n g t h e
compressionstroke (Bro et al.,1977).
( B A N D SI N C L U D E 9 5 % O F
ACTUAL DATA POINTS)
E
MI
2-OO
=
0
= =-
OEM INDOLENE
0.06
-
DSR ETHANOL
O.| |
oN
o
Gonclusion
Ethanolseemsto be an attractivesubstitutefor
o e t r o l e u mf u e l s i n t h e S l i n t e r n a l c o m b u s t i o n
e n g i n e .l t s t w o m o s tp o s i t i v eq u a l i t i e sa r et h a t i t c a n
b e u s e d i n t o d a y ' se n g i n e sa n d c a n b e m a d ef r o m
renewableresources,such as grain.However,there
a r e p r o b l e ma r e a si n e t h a n o lu s e ,s o m eo f w h i c ha r e
l i s t e di n T a b l e 9 ( S c h r o c k ,1 9 7 9 ) .O t h e r p r o b l e m s
with its widescaleuse are its cost, productionand
d i s t r i b u t i o nt o t h e p u b l i c .
l n s u m m a r y t, h e f o l l o w i n gg e n e r a l i z a t i o ncsa n
be made based on the literaturereviewedin this
paper:
P I N T O A 3 O OC C E N G I N E
M B T S P A R KT I M I N G
aOOO R PM - ALL LOADS
I
.L
I
o u t o f t h e e n g i n e .l t h a s b e e n f o u n d t h a t e t h a n o l ,
b e i n ga n e x c e l l e nst o l v e n tw
, i l l l o o s e nu p g u m sa n d
d e p o s i t sa lr e a d yf o r m e di n t h ee n g in e .O n e p r o b l e m
w i t h t h i s i s t h a t w h e n e t h a n o li s f i r s t u s e d i n a n
e n g i n e ,o n e s h o u l d e x p e c t t h a t s o m e f i l t e r s m a y
clog up due to the gums and depositsbeing
cleansedfrom the engine.However,afterthe engine
i s i n i t i a l l yc l e a n s e dt h e r es h o u l d n o t b e a n y m o r e
p r o b l e m sw i t h c l o g g e df i l t e r s ,u n l e s st h e e t h a n o l
c o m e s i n t o c o n t a c tw i t h s o m e o f t h e i n c o m o a t i b l e
m a t e r i a l sm e n t i o n e de a r l i e r( R i d e re t a l . ,1 9 7 9 ) .
r.60
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E e u r v A L E N cnE
F i g . 1 4 . - T h e a l d e h y d ee m i s s i o n s o fa n S l e n g i n e f u e l e dw i t h
e t h a n o l s h o w v e r y s i g n i f i c a n ti n c r e a s e sa t l o w e q u i v a l e n c e
r a t i o s . W h e n t h e e q u i v a l e n c er a t i o i s g r e a t e r t h a n 0 . 9 t h e
e t h a n o lf u e l e de n g i n e a p p r o a c h e s t h ei n d o l e n e fu e l e de n g i n e
b u t s t i l l i s s i g n i f i c a n t l yg r e a t e r .
D ep o si tsi n E n g i n e s
U si n g E th a n o l
ln the studies reviewed ethanol has not been
found to leave any unfavorable engine deposits.
I n o n e s t u d y p r a c t i c a l l yn o c o m b u s t i o nc h a m b e r
d e p o s i t sw e r ef o u n d i n a n e n g i n ea f t e r5 0 0 h o u r so f
o p e r a t i o no n e t h a n o l ( M e y e re t a l . , 1 9 4 8 ) .I n f a c t
e t h a n o ld o e s j u s t t h e o p p o s i t e .l t c l e a n sd e p o s i t s
17
1 ) T h e h i g h e rp r o o fe t h a n o (l ) 1 8 0 ) i s a m o r e
s u i t a b l ef u e l f o r t o d a y ' se n g i n e sd u e t o i t s
increased power output, increasedvolum e t r i c f u e l e c o n o m y ,a n d t h e a b s e n c eo f
d ithlower
s o m eo f t h e p r o b l e m sa s s o c i a t e w
p r o o fe t h a n o , .
2 ) E t h a n o li s m o r e a d a p t a b l et o u s e i n s p a r k
i g n i t i o ne n g i n e st h a n i n d i e s e le n g i n e s .
3 ) W h e ne t h a n o il s u s e di n a S l e n g i n e m
, o d i if c a t i o n ss h o u l d b e m a d e t o t h e c a r b u r e t o r ,
c o m p r e s s i o nr a t i oa n d i g n i t i o nt i m i n g ,a n d
someadditionalform of heatmay be needed
f o r t h e i n t a k ea i r .
4 ) W h e n c o m p a r e dt o g a s o l i n e ,e t h a n o l d e livers more power, betterfuel economy,
h i g h e r t h e r m a l e f f i c i e n c y ,b u t l e s s v o l u m e t r i cf u e l e c o n o m y .
5 ) S o m ea d d i t i o n afl o r m o f h e a to r a s e p a r a t e
startingfuel is neededto start engines
operatingon ethanolat low temperatures.
6) E t h a n o il s l e s st o x i ct h a ng a s o l i n eb, u t m o r e
p r e c a u t i o n sm u s t b e t a k e ni n i t s s t o r a g et o
i n s u r ei t s i n i t i a lq u a l i t y .
7 ) E t h a n o l i s c o r r o s i v et o s e v e r a lm a t e r i a l s
u s e d i n v e h i c l e s c u r r e n t l y o p e r a t i n go n
g a s o l i n eT. h e c o r np a t a b i l i t o
y f m a t e r i a l isn a
vehicleshould be checked before usinq
ethanol.
8) T h e N O X a n d C O e m i s s i o n sa r e l e s s ,a n d
t h e u n b u r n e df u e l a n d a l d e h v d ee m i s s i o n s
are greater for ethanol as compared to
gasoline.
9 ) T h e r e s e e m t o b e n o m a j o r p r o b l e m si n
e n g i n ed u r a b i l i t yu s i n ge t h a n o lt h a t c a n n o t
be overcomewith minor modifications.
10) There are no unfavorableengine deposits
l e f t i n e n g i n e su s i n ge t h a n o l .I n f a c t ,t h e r e
are fewer engine depositsthan found from
the use of gasoline.
Eventhough there are some problemsassociated with its use,ethanolhas been used as a gasolinesubstitutebefore,andtherearenoinsurmounta b l e p r o b l e m st o k e e p i t f r o m b e i n gu s e da g a i n .A
greatnumberof barriersexist in the useof unmixed
ethanolin dieselenginesbecauseof the low cetane
numberforethanol.Tomakeitsusepracticaltoday,
there are active research programs around the
world investigating
these problems.
in Engines.
Table9.-Summaryol EthanolApplications
Approximateo/o
Fuel Replaced
by Ethanola
200 Proot
EthanolVatue
Potentialc
Problems
No
. 7 5x g a s o l i n e
1,2,5,7
100
Yes
. 6 7x g a s o l i n e
3, 4,7,I
Naturag
l as lrr engines,
old Sl tractors
100
Yes
. 7 6x g a s o l i n e
3, 4,7,I
C l t r a c t o r sc, o m b i n e s
100
Yes
. 5 2x d i e s e l
4,6,7,9
Application
Engine
1 ) Ethanol-gasoline
mixtures
V e h i c l e sa n d o l d e r
Sl tractors
2 a ) E t h a n o li n
S l S t d .C R
V e h i c l e sn, a t u r a lg a s
e n g i n e s o, l d S l t r a c t o r s
2 b ) E t h a n o li n
Sl HighCR
10
Utilize
Low Proof?
3)
E t h a n oiln S l
c o n v e r t e dd i e s e l s
h i g hC R
4)
E t h a n o li n d i e s e l s
C l t r a c t o r s c; o m b i n e s
100
Yesb
. 5 5x d i e s e l
4,5,7,8,10
5)
Ethanol-diesel
m txtures
C l t r a c t o r s c, o m b i n e s
10
No
. 5 1x d i e s e l
1,4,6,7,'10
6)
Carbureted
e t h a n o lC l
C l t r a c t o r s ,c o m b i n e s
30
Yes
. 5 5x d i e s e l
11
a A s s u m i n g10 0 o /aod o p t i o n
Dspeculative
c P o t e n t i a lP r o b l e m s
1 - P h a s es e p a r a t i o n
2 = Driveability
3 = V a l v er e c e s s i o n
4 = S t a r t i n g( b e l o w4 0 " F )
5 - V a p o rl o c k
6 = U n a v a i l a b i l i t yo f r e t r o fi t c o n v e r s i o nh a r d w a r e
7 M a t e r i a l sc o m p a t i b i l i t y
8 I n j e c t o rp u m p l u b r i c a t i o n
g - o i l d i l u t i o na t l i g h tl o a d s
l 0 C o m b u s t i o nk n o c k
1.1 Inconvenience
GLOSSARY OF TERMS
A/F
BTC
Cl
DSR
<D
FTIRS
FTP
IHP
MBT
Ml
Ml
NFPS
NOX
OEM
Sl
WOT
Air to fuel ratio
Beforetop deadcenter
C o m p r e s s i oing n i t i o n
inductionsystem-sonicflow fuel/airinduction
Dresserator
Equivalence
ratio-actual airlfuel ratio
stoichiometric
airlfuel ratio
Fuoriertransform
infraredspectroscopy
Federaltest procedure
Indicatedhorsepower
M i n i m u ms p a r ka d v a n c ef o r b e s tt o r q u e
M a l d i s t r i b u t i oi nnd e x
O richestcvlinder- leanestcylinder
2 x O average
NationalFireProtectionSocietv
N i t r o u so x i d e s
Originalequipmentmanufacturer
S p a r ki g n i t i o n
Wide open throtile
18
Bibliogr aphy
1 . A D M C o r o . 1 9 8 0 . C o r n P o w e rF u e l e d 1 9 7 9 F o r d
1 6 . M e y e rA
, n d r eJ . a n d R . E . D a v i s1. 9 4 8 D
. evelopment
o f a P r a c t i c a lM e t h o d o f B u r n i n g A l c o h o l i n a
G a s o l i n eT r a c t o r .U n i v e r s i t yo f K e n t u c k y ,L e x i n g ton, Kentucky.
1 7 M i n g l e ,J o h n G . O c t o b e r. '9l 7 9 .C o n v e r t i n gY o ur C a r
t o R u n o n A l c o h o lF u e l s .O r e g o nS t a t eU n i v e r s i t y ,
C o r v a l l i sO, r e g o n .
F i e s t aC
. e d a rR a p i d s ,l o w a .
2 . B a i l e y , B . K . a n d J . A . R u s s e l .1 9 7 9 . E m e r g e n c y
F u e l sC o m p o s i t i o na n d l m p a c t ,P h a s el l F o r m u l a t i o n a n d S c r e e n i n gD i e s e lE m e r g e n c yF u e l s .M E D
R e o o r t 1 0 1 . S o u t h w e s t R e s e a r c h I n s t i t u t e .S a n
A n t o n i o ,T e x a s .
e
B r o , K l a u s a n d P . S . P e d e r s o n 1. 9 7 7 .A l t e r n a t i v e
D i e s e lE n g i n eF u e l s ;A n E x p e r i m e n t aI ln v e s t i g a t i o n
o f M e t h a n o l ,E t h a n o lM e t h a n ea n d A m m o n i a i n a
D . l . D i e s e lE n g i n ew i t h P i l o t I n j e c t i o nS. A E P a p e r
. a s s e n g ecr a r m e e t i n go f S A E ,D e t r o i t ,
N o . 7 7 0 7 9 4P
Michigan.
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A l c o h o l - P o w eTr r u c k .M o t h er E a r t hN e w s .S e p t e m b e r l O c t o b e r1 9 7 9 .
1 9 . M u e l l e r A s s o c i a t e s ,I n c . 1 9 7 8 .S t a t u s o f A l c o h o l
U t i l i z a t i o nT e c h n o l o g yf o r H i g h w a yT r a n s p o r t a t i o n .
D O E C o n t r a c tE C - 7 7 - X - 0 1 - 2 9 2 B
3 .a l t i m o r e ,M a r y land.
C h u i .G . K . . R . D . A n d e r s o na n d R . E . B a k e r .1 9 7 9 .
B r a z i l i aV
n e h i c l eC a l i b r a t i ofno r E t h a n oFl u e l sF. o r d
, ichigan.
M o t o rC o m p a n y D
. e t r o i tM
20. N e r p e l C
, h u c k .1 9 8 0 B
. o o z eB u r n e r sT, h e D e b u to f
t h e A l c o h o l i cA u t o m o b i l e .A D M G a s o h o l N e w s .
F e b r u a r y2 7 , 1 9 8 0 .
D e a r d o r f f ,T . 1 9 7 9 .O p e r a t i o no f a S p a r k - l g n i t i o n
E n g i n ew i t h a R a n g eo f E t h a n o lo n W a t e rM i x t u r e s .
l o w a S t a t eU n i v e r s i t yA, m e s ,l o w a .
b.
21 P a u l ,J . K . 1 9 7 9 E
. t h y lA l c o h o lP r o d u c t i o n
andUse
a s a M o t o r F u e l . N o y e s D a t a C o r p o r a t i o n .P a r k
R i d g e ,N e w J e r s e y .
D u c k . J . T . a n d C . S . B r u c e . 1 9 4 5 .U t i l i z a t i o no f
N o n - P e t r o l e u mF u e l si n A u t o m o t i v eE n g i n e s N
. af/.
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Y o r k ,N e w Y o r k .
. asolina
E n g e l m a nH, e l m u t hW . 1 9 8 0 G
e n dD i s t i l l e d
A f c o h o l C o m p a r e di n a n E n g i n e .l n L o o k i n g a t
Alcohol Fuel:Farm Productionand Use.Ohio State
, o l u m b u s ,O h i o .
U n i v e r s i t yE x t e n s i o nS e r v i c e C
P e r s i a n t s e v aV,. P . , l . L . R o z e nife l d ,V . E . Z o r n i a ,E .
K . E n i k e e va n d M . l . C h a r a e v a1. 9 8 0 .P r o t e c t i o no f
M e t a l s , T r a n s a c t i o n so f t h e Z a s h c h i t a M e t a l l o v ,
J a n u a r y1 9 8 0 .C o n s u l t a n t sB u r e a u ,N e w Y o r k ,N e w
York.
, i l l i a mJ . a n d C . W . F l o w e r s1. 9 7 9 .E n g i n e
8 . F l o w e r sW
M o d i fi c a t i o n sf o r t h e U s e o f A l c o h o l F u e l si n S o a r k
l g n i t i o nE n g i n e sN
. i c h o l l sS t a t eU n i v e r s i t yT,h i b o d a u x ,L o u i s i a n a .
24 P y e , D . R . 1 9 3 7 .T h e l n t e r n a lC o m b u s t i o nE n g i n e ,
V o l u m e/ . O x f o r d U n i v e r s i t yP r e s s .L o n d o n , E n g land.
9 . G a l l o p o u l o s ,N i c h o l a s E . A l t e r n a t i v eF u e l s f o r
R e c i p r o c a t i n gI n t e r n a lC o m b u s t i o nE n g i n e sA
. ltern a t i v e H y d r o c a r b o nF u e l s : C o m b u s t i o n a n d
C h e m i c a l K i n e t i c s .P r o g r e s si n A s t r o n a u t i c sa n d
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2 5 R i d e r ,A l l e nR . a n d D . P . S h e l t o n1. 9 7 9 .E t h a n o l - A
F u e l f o r A g r i c u l t u r aE
l n g i n e s .U n i v e r s i t yo f N e b r a s k a ,L i n c o l n ,N e b r a s k a .
. .1 9 5 3 E
. l e m e n t s olfn t e r n a lC o m b u s 26. R o g o w s k i , AR
t i o n E n g i n e s . M c G r a w - H i l lB o o k C o m p a n y , I n c .
N e w Y o r k ,N e w Y o r k .
1 0 .G o e r i n g , C a r r o l l E . 1 9 8 0 . B u r n i n g E t h a n o l i n
E n g i n e s l.n L o o k i n ga t A l c o h o l F u e l sF: a r mP r o d u c t i o n a n d U s e . O h i o S t a t e U n i v e r s i t yE x t e n s i o n
S e r v i c eC, o l u m b u sO
, hio.
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Gasoline?"PopularSclence.216:25-34.
2 7 S c h n i e d e rR, o l l i n .1 9 7 9 S
. a f e t yf o r E t h a n o P
l roduct i o n a n d U t i l i z a t i o nU. n i v e r s i t vo f N e b r a s k aL, i n c o l n ,N e b r a s k a .
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K a n s a sS t a t eU n i v e r s i t yM
, ansas.
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1 2 . H u n t , D o n n e l lR . 1 9 7 9 .E n g i n e M o d i f i c a t i o nfso r
B u r n i n g E t h a n o la s a F u e l .U n i v e r s i t yo f l l l i n o i s ,
U r b a n a l, l l i n o i s .
12
29. S p i n d l e r W
, . 1 9 7 8 .M a t c h i n ga T u r b o c h a r g etro a
P a s s e n g eC
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1 9 7 8 .E t h a n o li n M u l t i c y l i n d eAr u t o m o t i v eS l E n g i n e s ;A s t u d yo f P e r fo r m a n c ea n d E m i s s i o n sC h a r a c t e r i s t i cR
s e l a t i v teo l n d o l e n ea n d M e t h a n o lD. O E
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19
Office, College of Agriculture, University of Kentucky, Room S-105, Agricultutal
Science Building-North,
Lexington, Kentucky 40546
lssued in furtherance of Cooperative Extension work, Acts ot May 8 and June 30, 1914, in cooperation with the U.S. Department of Agriculture. Charles E. Barnhart, Director of
Cooperative Extension Service, University ot Kentucky College ol Agricullure, Lexington, and Kentucky State University, Frankfort.
l s s u e d8 - 8 1 , 1 M ; 1 M - 1 1 - 8 1