TROUBLESHOOTING THE GAS ENGINE

By Staff
1 / 5
Courtesy of Everett R. Shreeve, Salamonia, Indiana
Courtesy of Everett R. Shreeve, Salamonia, Indiana
2 / 5
Courtesy of Richard Sundberg, Stanton, Iowa 51573
Courtesy of Richard Sundberg, Stanton, Iowa 51573
3 / 5
Courtesy of Morris Blomgren, Rt. 1 (Falun), Siren, Wisconsin 54872
Courtesy of Morris Blomgren, Rt. 1 (Falun), Siren, Wisconsin 54872
4 / 5
Courtesy of Taylor Grammer, 711 North Hemlock Street, LeRoy, Illinois 61752
Courtesy of Taylor Grammer, 711 North Hemlock Street, LeRoy, Illinois 61752
5 / 5
Courtesy of Taylor Grammer, 711 North Hemlock Street, LeRoy, Illinois 61752
Courtesy of Taylor Grammer, 711 North Hemlock Street, LeRoy, Illinois 61752

Star Rte. 2, Gunnison, Colorado 81230

On page 32 of the Mar-Apr 1967 GEM, Fred Gertje of Orofino,
Idaho, inquired as to the identify a certain engine he had. The
best clue I found as to its identify was ‘valve in head with a
post between the valves with a spring on it and a plate that
connects the post with the two valves.’ The only engines I have
seen with this arrangement are Hercules built, and since it was
painted red I would conclude that it is probably the Economy engine
built for Sears Roebuck by Hercules. All other parts of Fred’s
description compared to this engine except the water jacket and
cylinder being cast together. On a 5 HP engine this should have
been two pieces, the hopper being removable. Further correspondence
with Fred revealed that it was. One of the slight differences I
have noted between the Economy and Hercules engines is the square
cornered hopper of the Economy, the Hercules having fairly rounded
corners.

The drag, or automatic poppet valve on the intake worked fairly
well with slow speed engines but had some drawbacks. The fuel-air
mixture enters the cylinder when the downward movement of the
piston causes the outside air pressure to exceed the internal
pressure and pushes the valve open. However, as the piston reverses
direction and starts its compression stroke, the intake air is
still flowing into the engine. The sudden reversal of flow causes
some of the mixture to reverse and escape before the valve can
close. Then the valve shuts so hard it tends to bounce and reopen,
losing more of the mixture. This could be prevented by using a
stiffer spring, but this would prevent the valve opening soon
enough on the intake stroke.

The design and tension of the intake valve spring is quite
critical to proper operation of the engine. The spring should not
increase rapidly in tension as it is compressed, so it should have
as many turns as possible without interfering with the maximum
opening movement of the valve. If an intake valve spring must be
replaced it should compare as nearly as possible to the original.
If this is not possible, a trial and error method must be used.

This is the picture of my display which I took four places this
past summer. Two Fordson tractors, one 1927 and one 1926 and 6 gas
engines, one 1? H.P. 1922 Hercules, one 1? H.P. 1922 John Deere,
one 6 H.P. Fairbanks Morse 1917, one 1? H.P. 1934 single flywheel
McCormick Deering, one 1? H.P. 1933 Fairbanks Morse single
flywheel, one Maytag single cylinder and one 850 Dulso light plant.
I belong to the Tri-State Gas Engine and Tractor Club of this
area.

One method is to use a lighter, longer spring than the original
and, using washers to increase the tension, adjust until
satisfactory operation of the engine is reached. Satisfactory being
the smoothest operation at the rated RPM with the least fuel
setting. The tension can then be measured with a small spring scale
and a spring of the proper size and shape and tension can be made
or, hopefully, found.

The post between the valves on a Hercules holds a spring loaded
plate that is attached to the intake and exhaust valves. In
operation this is supposed to limit the depth of the valve opening
against the regular spring so that it closes quicker but with less
force. The outward inertia of the plate as the valve closes tends
to momentarily lock the valve shut until the compression pressure
builds enough to hold it shut. This was advertised to increase fuel
economy.

Fairbanks Morse had a patented devise that worked similarly but
was of different design. It was a friction spring that pressed
against the sides of the regular spring retainer, the friction
preventing rebound, chatter, and fuel loss.

For proper operation of the automatic valve, it must move very
freely. However, it must not have excessive stem clearance from
wear or misfit, since air will be drawn in around the stem instead
of through the carburetor or mixer and thus cause too lean a
fuel-air mixture. Since the valve receives considerable heat from
the engine it should be lubricated with SAE 30 or 40 weight oil
after the engine warms up. Excessive oiling will cause coke and
carbon to form which can bind the valve.

On a lighter note, a friend once told me this story: A small gas
engine had been rigged to run some power driven farm items. To
prevent moving it to run the washing machine, a long belt was
improvised to reach to the machine on the back porch. One morning,
just as the farmwife was putting clothes into the machine, the
wildly flopping belt caught on the machine and drug it off the
porch and across the yard with the lady in wild pursuit. The
washing machine finally upset and the lady fell over the top of it.
Doubtless, she had some admiring thoughts for gas engines in
general!

And on a more serious note – be careful with belts, gears and
flywheels, for all the being sorry in the world won’t solve a
careless moment and a serious accident.

This is a picture of a John Deere ‘GP’ tractor. This is
a 1930 tractor and the serial number is 218751.

I bought this tractor at an auction sale north of Cumberland,
Wisconsin, about the first of October 1966. I was just wondering if
any one would know when this one was built. I am sure, it was
before they had farm tractor tires because someone put some road
building tires on the back, 12 ply. It has a brass plate on the
side of the motor block saying Continental Moror’s Powerful as
the Nation. On the. front top of the radiator, it is stamped
United. On the side of the radiator it is stamped Allis Chalmers.
My dad’s brother bought one of this type Allis Chalmers in 1930
and on this it is stamped only Allis Chamers on the radiator.

On Page 34 in March-April magazine–the car you show in this
picture is a Model A. Saxon car manufactured by the Saxon Motor
Company of Detroit, Michigan and was on the market in 1917 and
1918. It is a two speed forward, high and low and reverse. The
transmission is mounted on the rear axle housing. The motor is a
Continental Motor. It had a very good motor. At that time it had a
lot of good features that later were used by other car
manufacturers after the Saxon Motor Co. discontinued the
production. The car in the picture is identical to one I had which
I drove for many thousand miles.– Orlando Iverson, Box 107, Ada,
Minnesota.

This is a picture of myself and a small tractor I made. It has a
Crosley motor, two clutches, hyd. control lift. You can see the
hitch and control arms on the front end.

It is complete with governor, instrument panel, hyd. brakes,
three speed transmission. I call it the ‘Cobra’.

This is one of my gas engines just as I moved it home and
haven’t done any thing to it. It is a Fairbanks Morse, 50 H.P.,
190 R.P.M., hit and miss igniter. The flywheels are 72′ in
diameter It’s an 8 spoke wheel, 16′ diameter, piston. I
don’t have too much of a story about this engine. I will have
it later on. The weight I would like to know. I would like to hear
from anyone knowing anything about this engine.

  • Published on May 1, 1967
Online Store Logo
Need Help? Call 1-866-624-9388