Allis model b

Plowboy1972

New User
Just purchased an Allis Chalmers model b. Joined a local club. Went to my first show and pulled a 146%. Not sure how good that is for a stock 1949 CE low octane. Does anyone have any tips on improving that. I?d rather not dig to deep into the motor. How about I little head work? How to improve intake and exhaust using today?s fuel. How about tire pressure on a 2200lbs tractor on 9.5-24 Sat II 23 tires? Also, for the life of me I can not find the Fire, Center marks on the flywheel! I?ve had someone turning it over by hand slowly, looking in the hole with a flashlight and my readers on, and can?t see it. Not a dot, hashmark any sort of marking. I have installed 12v starting system. Other than that it?s stock.
 
To increase the HP of an engine, you raise the compression, increase the bore/stroke, increase the RPM's or install a larger carburetor. Doing any cylinder head porting will be an absolute waste of time on an engine like that. Increasing compression or bore/stroke is beyond what you are willing to do. A larger carb and more RPM's will get you more HP. Get one off of a D15 or D-15 S2 and make it fit the engine.
 
Thanks for the reply. I understand going with a
bigger carb. How can I raise the rpms. Governor
upgrades our mods?

Thanks
 
If your engine is new enough, just use a D-15 governor spring. That will yield 2,200 RPM when adjusted right.
 
They make a stiff wire brush that will work in a electric drill what will go into the inspection hole. I would guess you will find it when cleaned to where the flywheel looks like new steel on the edge.

I started pulling with an Allis Chalmers stock C. Same engine as your B. I was told I could get more HP with a stronger spring. What I found when pulling on a transfer sled as soon as the tractor took on a load the rpm dropped way before the traction give out and it might have gained an inch or two if any. I went to a cot spring, which is almost like using a piece of bailing wire direct to the carburetor, that would take the RPM to its fuel limit. this was not much faster that the heavy Allis spring. I drilled out the power jet a slight bit until I had the RPM as fast as I thought I could get by with. Same results as before. Without more engine it was not going to gain me much if any more distance on the track. Over the next winter I removed the head and milled .150 off that head. When I started pulling again the engine would support the extra RPM and I could see some extra gain in distance. The next year I installed small block Chevy valves and reamed out the ports to 1 1/4". This also gave me more wins than before. Because of competition from a cousin all reason went out the window. This is when I went to a 4 inch stroke, a crane ground camshaft with larger valves and all the restrictions removed from the below the valve seats. The original carburetor received a larger power orifice and venturi. I built a pulling track at the edge of my yard in a field to try all changes I made in the carburetor along with what the different balance an air pressures did.

The first head hand reamed first then milled.
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This not the head I run but the same work was done.
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