The Stovebolt Site Forums The Shop Area Engine Shop aluminum pistons?

WHile looking at parts for my chevy 350 rebuild. I came across flat top pistons with valve reliefs, but they are made of aluminum? T-5 heat treated. Never heard of aluminum pistons, is this a proven material for pistons? Anyone have any experience with these? COmments? Pros? COns?

So what did you expect them to be made out of? Adequate pistons are cast aluminum. The next better is T5 heat treated. Forged aluminum is for high performance.

you can't be serious.

I know it's not a truck, but I have an aluminum piston from my plane sitting right here on my desk. I've never seen a modern aircraft engine with anything other than aluminum.
Dave Evans
52_3100

Because of the reciprocating motion of the pistons, aluminum can be a big advantage over steel/iron. Aluminum is about 1/3 the weight of steel. Less stress on the connecting rods, wrist pins, crankshaft, bearings, etc. For a high performance engine at high RPM's, all the better. Better efficiency (more energy devoted to turning the crankshaft instead of reversing the motion of a heavy steel piston), thereby higher gas mileage.

As long as the parts are properly engineered, they're a good idea.

Dave Evans
52_3100

My Diamond T, built in 1947, has a Hercules JXC engine with aluminum pistons. This engine is a pre-war design, flat head (L-head) six cylinder. They knew the advantages of aluminum back then and pointed this out in their advertisements.

Kent

Chevrolet was among the last to shift to aluminum pistons, changing over from Iron in 1953. Every 350 ever made has had aluminum pistons of some sort.

The original post was a joke, wasn't it? If it was serious, find somebody who knows what he's doing to rebuild your engine!
Jerry

Either you are 12 years old,or have been living in a bag for a lot of years.I agree with Jerry.

wow guys, lighten up - if someone who wasn't too familiar with engine building had only heard of pistons referred to as "cast" or "forged", it wouldn't be a surprise if they didn't twig they might be aluminum .... doesn't mean the person is incapable of being educated

Bill

I agree with Bill. This site should be to inform people who do not know everything (including me), even beginners.

X3...!!!!!

Boy, I was asking a simple question.... I have not rebuilt 3000 engines as you guys have apparantly? I also have not seen everything or know everything about engine material composition. Must be lonely up there at the top fellas?
I have however rebuilt 5 or 6 different motors, successfully I might add. Thinkin this will be my last question. SOrry for wastin your precious time. And I thought my brother in law knew everything!!

Brian,
I dont think that a few inappropriate comments is a fair representation of the rest of us. This is a very informative forum that I have learned alot from, and I have been a mechanic for over 30 years. I would urge you to continue to read and ask questions. If this knowledge is not passed on, what good will it do?

Brian
Please don't take the comments made here too seriously.
I apologize for the others.
We are not all jerks.

its lame to run a guy off for asking a question.. no one is born knowing this stuff - it is picked up by observation, research, and asking questions. In my opinion, the guys who insulted Brian (calling him 12 years old? really?) owe him an apology...

I do apologize,Brian.

....and we have always had an "agreement". There is no such thing as a stupid question here Amen, Church is out. Lets go home and play.

Brian, we're still pulling for you.

I am also surprised at those negative reactions to a simple question. This is not the way this site normally operates or should operate.

Brian, stick with us. We can be a civil and engaging bunch!

Hy Brian_Ostner, I'm a retired mechanic (not a technician), and I'm the first to admit I don't know everything about vehicles and there components. I'm here to try and pass on what I have learned, so that others may enjoy the old vehicle hobby. I hope you stay with us and learn what we can and will teach you. Some of my fondest memories of my working years, were the times I worked with and trained apprentices, it gave me a great feeling to pass on what I could to them to help them gain their tradesmans qualification. Please give us another chance.

You did not begin by asking "what are pistons made of?" or "are pistons made of aluminum". Your first statement was that you never heard of them.
He's rebuilt 5 or 6 motors, and never heard of aluminum pistons?

What pistons did you use?

He asked for comments. I don't feel like my comment was out of place. "So what did you expect them to be made out of? Adequate pistons are cast aluminum. The next better is T5 heat treated. Forged aluminum is for high performance.

Well, maybe he's only done early engines with Iron Pistons. Pre WW2 perhaps. But it was an oddly worded question from someone who's rebuilt that many engines of any kind. Mea Culpa.

Ok, what type of engines were you building? I mean you can get them for some of the old engines (these included) but unless you are completely set on an absolute concours restoration, there would be no reason to use them. I have seen them in 7000 horsepower diesels on ships, but that is about it.

I remember when I built my first engine in 1973, a '53 235 powerglide, I was surprised that the new pistons were aluminum. All the old books and manuals I had read indicated that the Chevy had CI pistons. I had taken a few old lawnmowers and compressors apart as a kid, and they had CI pistons.

I have also rebuilt the motors in various tractors, all had cast iron pistons, and the tech literature referred to the pistons as CI. I chose to use NOS CI pistons in a couple of them because newer piston were high compression aluminum, and would prevent me from running the engines on keroscene.

So you know what? It sure would be easy, depending upon what you have read and worked on, to assume that CI Is the normal and usual material for a piston, until you find out differently.

I think the guy was doing the right thing by asking the question, because then he would get a little assurance that he was on the right track, and find out what his options were.

Just my 2 cents.

Kurt

Right, he accidentally rebuilt 5 or 6 engines with iron pistons. That happens a lot, while Roosevelt was president. Not so much since WW2.

I can see where it would be confuseing. Even though alum. pistons have been the standard for many years, ads, articles, & specs still all point out aluminum pistons.

I guess that would depend on when you were rebuilding engines after WWII and what engines you are referring to. Kurt's post is pertinent for those of us who only know Stovebolt engines. Eight years after WWII, aluminumrips tons or cast iron pistons were used on different 235 engines, and cast iron pistons were used on all 216 engines. In 1954 all Stovebolt engines used aluminum pistons (cast alloy aluminum).

Of course, this thread started referring to a 350 engine. I thank those who posted replied that sought to teach us rubes something about those later small block GM eights. As others eloquently posted above, this forum is best used as a venue to help, explain, and advise.

Ok, I first apologize for not using the correct verbage in my first post. I do need to be much more detailed when I explain what it is I am tryin to do.

Also, I do not hold everyone here to any kind of standard? I do however feel 99% of stovebolters are decent, fair, intelligent people trying to pass on information to others.

WHen I asked about aluminum pistons, I was tryng to learn the differences between what was available in pistons in the rebuild kits out there. I grew up on a grain farm here in Central NJ, my first two engine rebuilds were a Massey Harris Tractor and an Old Mack my friends grandfather wanted to restore. Think it was from the 1930's? The other engines were modern lawn tractor and truck engines. I noticed the kits offered three different kinds of pistons, but only one description said aluminum? Wanted to make sure i understood what I was reading so as to make an intelligent and informed decision. Thank you to all who replied with positive info. NO hard feeling guys. Brian