The Manchester journal. [volume] (Manchester, Vt.) 1861-current, 1916-08-24

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! What sire earburetor should be use
I for an eight cylinder engine Of eco Gu
=. bic inches displacement And VIVA
:! size for four cylinder 800 cubic inc
: engineer
!. The question OF a carburetor size 70
! cars coming under either Of thcs
!: classes varies considerably Ever
! though two cars have the same dis
< placement, the bore and stroke, length
Of valves etc, may differ, and thest
| are factors In determining the proper
I size. The same holds good with car,
! of any displacement.
How much gasoline should . motor.
car engine use per horsepower pei
| hour7
The quantity varies considerably. &c
cording to engine design but a fairly
reliable constant on which Il number
Of authorities agree f. one-eighth gal.
. lon OF gasoline having a specific grayi.
~ Of 0,75 per actual horsepower per
hour.
What proportion OF length OF con-
Meeting rod to length Of stroke 10 good
practice in long stroke engines?
About two TO one.
| 81
my carburetor only for a few seconds
after stopping tho motor2
Probably the float is not properly nd-
justed.
Kindly give your opinion as to the
value Of benzine to be substituted for
gasoline. Is it dangerous to use, and
will it injure the motor more than
sasoIine7
BenZine IS a richer fuel than gaso.
line and If properly carbureted is said
TO give more power. 1t starts easily in
summer although not as easily as gas
oline In winter II is advisable to Use
gasoline Benzlne Is not so volatile as
gasoline, but owing to the greater mum.
Der of heat units II contains Ii will |
develop more power. 1t does not evap
crate as readily as gasoline. There
should be no t'angcr from using It IL |
handled judiclously.
A disadvantage incidental to its use
has been that, owing to It's being richer
In carbon than gasoline, II would de-
post more Of this substance on the pis.
ton head and interior Of the combus
ton chamber. While this nay be true
of poorly refined benzine and when
the mixture proportions are not cor
rect, 1t applies equally well ,"hen low
grades Of gasoline are used and when
the mixture of gasoline vapor and air
supplied the cylinders s too rich.
Would there be advantage in having
q concave topped ston7 Would il
give moro force on the explosion
stroke?
Theoretically the more nearly spher.
cal the combustion chamber is the
greater the efficiency Of the engine. :
Hence conceived head is step In ,,
he right direction.
coes v with two cylinders, set at h
10 degrees, fire reeuIarIy--that is, every
60 degrees7 Also do eight and twelve
ylinder v motors fire at regular inter.
,als7 Are the cylinders Of an eight al
Ways set OF 20 degrees end those Of =
weIve at 90 degrees, and whyf ?
A engine with two cylinders set at =
0 degrees would fire every revolution =,
D one cylinder or the other. In a four =,
ycle motor each cylinder must fire h,
very two revolutions. Assuming that %
be piston is at the top of its compress i,
ion stroke, Just at the point Of going d,
own On the combustion or working II
troke, 1t will come up again at the b,
nd Of the exhaust stroke. These two bl
lnctions take one revolution. Then II %
oes down again to draw In the new
barge and comes up to compress this,
mother 800 degrees have now been Ia
overed, when the engine is again b
eady TO fire in this cylinder. M
In an eight the firing occurs every % -
egrees, 50 that all eight will fire In :,
NO revolutions for reasons above. In
twelve one cylinder fires every 60 de. I'm
rees, so that all twelve will fire IN nj
20 degrees, or two revolutions. If they m
id not fire regularly the balance ca
ould be upset at
The cylinders Of an eight should be
. 80 degrees so that one cylinder can
re every 90 degrees, and the cylinders di
! a twelve should be at go degrees fr
II the same reasons. This Is always
me. IA
Why is il that six and eight cylinder oii
otors are not used in trucks and in on
ICING cars2 tel
The eight cylinder motor Is com la
iratiyely new development, but 1t fa'
ay soon break into racing motor de- 10
On. Skies have been and are used In ca
,th racing cars and trucks. The main "
,jects Of added cylinders are greater We
noothness and hcxibility, and these Tn
g not regarded as necessity on a cas-
uck or racing car either for that