Re: Reducing displacement on a four cylinder gas engine.

I appreciate the effort that some responders exercised in answering my engineering questions. As for the others, no I will not be considering another tractor. This 400 has a side-mounted IH/GE Electrall and it will only fit SMTA thru 660 and similar W models. The 13KW generator will not fit AC, H. SH, C, or any green crapola.

This is the same tractor that I plan to convert into an Ice Cream making and vending unit. I already have the NSF freezer chest/soda fountain combo. It will attach to a front-mounted IH fast hitch. The White Mountain ice cream salt/freezers (4 or 5 ea) will go on the rear fast hitch. The ice crusher will probably drive off a IH cotton picker power supply gearbox. Fresh hot water will be conditioned with a heat exchanger. Still looking for a nice SS or aluminum 50 gallon water tank. May run the rotating freezer paddles with compressed air as the motors can stand indefinite periods of stalling. Ya, I am looking to save fuel. Aren't we all these days? I still need 1400 RPM.

I will probably start testing the 400 with loose plugs wires on 3 and 4. I'll do more testing with 3 and 4 sparkplugs removed. It seems to me that the most efficient configuration would be to eliminate those pistons. I am somewhat worried that the crankshaft flywheel flange may fatigue and separate with extended usage.

RAB

Thanks for the additional info. I can understand what you want to do now. Because you're driving an alternator, you need to keep the speed high regardless of load. I don't believe you will save that much fuel if you disable two cylinders, but it's worth a try.

The GM variable displacement engines, both the nefarious Cadillac 8-6-4 and the current "displacement on demand" motors, shut down cylinders by disabling the valves. I think that's the easiest route for you, and it's easy to reverse. I'm not familiar with the 400, but I assume it's an overhead valve engine. It should be reasonably easy to remove the lifters and pushrods as suggested by Johnski. You don't need to keep the valves open, though: The dead cylinders will work as big springs so that there is very little net power loss.