TROUBLESHOOTING THE GAS ENGINE

Two Fordson tractors

Courtesy of Everett R. Shreeve, Salamonia, Indiana

Everett R. Shreeve

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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.