Are pistons aluminum

[n4hwl]

Are these pistons made of aluminum. I would think that aluminum would not last as long as steel. If they are made of aluminum thats fine because they make to 400-500 k like they are . I was just curious. I remember other engines made of aluminum blocks in the past that were a real mess. .

Thanks
Ken

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1998 1/2 24 valve 2500 automatic 3. 55 alcoa aluminum wheels
Rhino Liner.

 

[HC]

I let experts add the details as to why, but I'm 99% sure that the answer to your question is "yes". The sealing technology for moving pistons (rings) is completely different than trying to seal a head gasket or valve seat, and of course it's a well-proven design, so you don't need to be concerned.

 

[Amianthus]

Yes, they are aluminum. But they are not pure aluminum. Pure aluminum melts somewhere around 900F. Cummins has spec'd an alloy for use in our trucks. What it is I couldn't tell you as I'm sure it is proprietary.
As far as it's application in our engines, Aluminum is the better choice for pistons. Steel pistons would weigh quite a bit more than our pistons do and that would be a lot of weight to be throwing around in there. The pistons are not machined tight to the cylider walls either, so differential thermal expansion is not really an issue as there are rings to take up the slop. A static seal of aluminum to steel is a bad idea, unless you account for it.
I will say this, based on experience, I wouldn't worry about the aluminum pistons. They are tougher than you think (or at least tougher than I thought). Anyone else?

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'99 2500 ISB QC SLT (No Leather!), 4x4, 5sp w/McLeod, 4:10, BD-II, PE, PE-EZ, 4"exh. , Pac-Brake, A-Pillar gauge pod w/boost and pyro, Line-X, V-1, lights, siren, lic. plt. frame says "Diesel Fumes Make Me Horny!", and much more goofy stuff.

 

[Bad340fish]

Aluminum disapates heat much faster than steel also, which I am sure is another reason for it. The aluminum blocks you are thinking had to have been the ones in the chevy Vega lol. They didn't have cast cylinder inserts and were very prone to premature wear. . so they were FOGGERS lol.

Clark

 

[trning]

Most all pistons theese days are aluminum. Some have steel inserts where the fuel is injected to handle the heat. and some are two piece pistons to allow for expansion. But all pistons are aluminum. Even on the big cummins N 14 that put out over 600 hp the pistons are aluminum.