VCCA Home Forums TECHNICAL - GENERAL Trucks and Vans New Chevrolet truck owner and pistons

I am new to this sight and thought I would start out with a piston question. Just bought a 1.5 ton 1933 Chevrolet truck (6OD01). It has been in a barn since 1952 and has 49000 miles on her. The engine is original (836915 A 4 3 SN T3454692) and never been apart. It has the original cast iron pistons. The ring grove is less then .003". Should I leave the cast pistons in or put aluminum pistons in?

I use cast iron pistons. The engines seem to run smoother then with aluminum. The counter-weights on the crank are sized for cast iron. I know that many others prefer aluminum but that is mainly based on modern engines and the feeling that the heavier cast iron will lessen the life of the bearings. It might be true if these engines were ever stressed but we don't drive them at speeds requiring high rpm so any additional stress is minimal.

If you use aluminum then lightening the flywheel should also be done. Then shave the head, port the passages, use bigger carburetor, install hardened seats and stainless valves. That way you can beat all the others at the strip.

My opinion is the cast iron pistons are fine for an engine that will not be used for extensive highway travel at high speeds. The lighter aluminum pistons place a lot less load on the rod bearings. I have used aluminum in my cars, engines ran smooth.
If you are reusing the orininal pistons in your 1933 note that the 1933 rings are not the same as any other year. I just happen to have a set of new standard size 1933 rings if you need them (Cheap).
If you are overhauling the engine be sure to have new wrist pins fitted in the pistons as they were usually quite noise at idle by 49,000 miles. My guess would be is that the engine already was overhauled once in its life time. This can be determined by seeing if the engine still has the original production style of rings.

Thanks for the info. I have not got the pistons out of the engine yet, but when I do I can measure the rings and let you know. If the pistons are good I will be interested in you rings. Thanks again