MTFCA Forum

This is slightly off topic but i know alot of T folks use aluminum pistons.
These russian guys make copper,bronze,brass and aluminum pistons and put them in a 4 cylinder engine and run it way to hard,the copper except for the wrist pin,held up the best.
https://www.youtube.com/watch?v=RLWSljLIBaw

I've never seen any pistons in IC engines that weren't high grade cast iron, or "piston steel", a kind of semi-steel, or some aluminum alloy or other. I've seen bronze crossheads, and babbit-lined steel or cast iron crossheads. Some pistons have tin plated skirts, and some appear to have steel heads and ring lands with some kind of alloy skirt. (Pontiac) Forged aluminum pistons have advantages, but most are cast.

Cast aluminum automotive pistons are typically “hyper eutectic” aluminum alloys, or extremely high silica content. Forged aluminum pistons are made from 2xxx grade aluminum alloys (as I understand). Modern cast pistons are aluminum with graphite coated skirts to prevent scuffing. Diesel engines commonly have 2 piece pistons consisting of iron tops and aluminum skirts coupled together by the wrist pin

I’m curious if these fellas have failures due to material failure, or insufficient design/machining…? Machining pistons properly is not as straight forward as one might assume, and each material change requires new design parameters

Most problems with aluminum pistons is caused be fitting to tight. Aluminum expands with heat at a greater rate than iron, so they need to be looser when cold. They will expand as the engine warms up, however, they can also seize if the engine overheats. In that case, you will stop faster than brakes can stop your car. and it could score the cylinder. Having said that, I use Aluminum pistons in all my cars, and as long as properly fitted and cooling system works well, have no problem. See other posts on fitting aluminum pistons.
Norm

Model T came with aluminum pistons. Whoever put them in failed to hone the wrist pins, a requirement for aluminium pistons. As note above, froze up, car stopped pretty quickly. Engine needed a serious overhaul, had it done professionally as absolutely everything needed to be replaced on engine and transmission. The fellow doing the work sent me pix of the aluminium piston melted. One serious lesson learned!

Oil consumption used to be normal, even in fine cars. Aluminum pistons had some problems early-on, but better engineering design, experience, and better piston rings greatly reduced problems, including oil consumption, noise, collapsed skirt issues, cracking, and seizing. Better cooling systems contributed to lowering oil consumption and allowing more precise fits. Mechanics had to re-learn fitting procedure.

TXGOAT2 wrote: ↑

Fri Nov 10, 2023 9:16 am

Oil consumption used to be normal, even in fine cars.

X2. If one watches old movies, you will notice most prewar cars leave a puff of smoke when taking off.

Like a dummy I traded it in when I got my truck but my 96 cadilac had the Northstar v8 in it, ran like a striped ape, but from I was told, they had to loosen the tolerances at GM when the engine first came out and it was normal for it to use some oil. mine used a quart between changes.