I have a few sets of TRW forged 360 pistons. Any idea how I can remove some excess weight from the pistons?

google this.

how to lighten race pistons

going with a lighter pin after you lighten them will help big-time.

There was a guy who seemingly did that for a living. Can't remember his name or much else. But I found a company online;

http://www.rebco-machine.com/About.cfm

One of the areas where they had extra material was in the piston crown, many are quite thick. Another place is the pin boss.

I know it was talked about back in the day, when you couldn't buy custom forged pistons at the corner drug store.

R.

Machine time is money. How effective do you think this will be in dollars spent vs results, compared to just buying some nice pistons

Patterson racing does that if I remember right

Please do not confuse the issue with logic.

A friend I bought my 1969 Dart from 30 plus years ago sold off everything he owned in PA and moved to Florida to get into the pizza business. After serveral years he became Friends with some MOPAR Super Stock racers and they put him to work (FREE labor). His job was to take brand new Venollia Pistons out of the box and hand-grind the piston under dome and pin boss area till the pistons came into a certain super lite weight. At this point the piston only lasted 50 passes and were removed and scraped so YES it can be done. but I sure as heck wouldn't want to start with some of the heaviest pistons out there.

I have used Rebco Machine for lightening, gas ports and modifications. They do good work at a reasonable price. That being said unless you are required to run those pistons or they are some rare pieces, I would put the money towards new pistons.

As I alluded to above, there was a time when the ONLY forged pistons you could get for most engines were TRWs. Back then Speed Pro was a competing brand.

So if you wanted to race something different you sent your TRW clubs out to be lightened. Or you found a way to use a different engine family's lightweight forged pistons.

I had a friend who used to race Pontiacs and he had a devil of a time because the only forged connecting rods for Pontiac that'd work in his 400 were factory from 58 to 62, something like that. And they weren't stout either but they didn't fail like the later cast rods did.

Back to now.......The OP has a stash of brand new heavy forged pistons and a new set is starting to cost something like $800, unless you can find a sale or shop cleanout. So if the pistons right now are pretty worthless, if he invested say $200 in a set to get them lightened up to the point where he'd want to use them, he'd be money ahead.

To the OP: If you have more than one set of the same piston maybe you could get a discount because their setup time would be reduced.

Now I feel better!

R.

But the point would be....it wont matter. After lightening, they would just be frigate anchors instead of destroyer anchors. The difference would never be seen in anything other than an all out, stocker prep type assy. And these days, if building something like that, you sure won't be using TRW pistons. So either run em as is and save the $200 for something that matters, or buy pistons.

Now if he is just looking for a way to knock some grams off to make them balance, that's one thing, but lightening for performance would be a waste of money for zero gain

As stated already, is the work worth what little you may gain?
You may be able to sell 2-3 sets and then buy set of Diamond,Ross,Wiseco,etc.

You don't suppose the man has his own mill and is looking for guidance on how/where to remove/not remove material so he still has a piston when he is done and not a paper weight??

Kevin

Put them on a UPS truck and send them to a new owner.

It's like that old joke, I just lost 200 lbs of ugly fat, how? I got a divorce!

call Eric at Rebco Machine and ask how much weight he can remove and the cost. Then you can make a informed decision on what direction to go. all they do is modify pistons.

316-440-2828

So true. A lot of the people I know either own, or have access to a mill to play around with. Send them here or buy that. I think the op just want to use what he has without ruining them. Not everyone wants to or cares to run 8's with the latest greatest lookie what I bought parts. Sometimes life just doesnt allow it.

I've been a machinist for 20+ years, have access to equipment & i wouldn't spend my time on them ... time is money.Unless he has to use them for some class rule, I would sell them & buy a better,lighter set of pistons.
If this is on a street/strip or bracket car that's not going to be turning a lot of rpms, i doubt it would make a difference over an untouched piston. You'd be surprised how much material you have to take out to make 10-15 grams, been there done that. A lot of the guys here have probably run in the 9s with the older TRW/SP heavy slugs, but it takes a toll on the rest of the rotating assembly.

I think Montes point was..... Even if you took out 50 grams, unless it's a pretty high effort combination(like the kind where you wouldn't even consider using these pistons in the first place), there will likely be almost zero gain in ET.

Fwiw, my friends NHRA "spare" stocker motor uses trw pistons(unmodified as per the rules), and it runs within about a tenth of the one with the high dollar pistons in it(which is also about 6 cubes bigger).

I have friends with tool rooms. As in can make anything you can imagine. We were talking about wire EDM the bore's, because we can. lol
we are CNC'ing an intake for my HEMI now, it will be done pretty soon. I come up with ideas and measurements and if I can't make it on my mill or lathe, their happy to help, because RACECAR!😛
If this guy has access to the equipment and does the work, what's he out but time and beer.😁

My purpose of this post is that I want to try a turbo and make about 600 HP using parts that I have. Factory 360 crank is good for 600 HP. I have plenty of lighter H beam rods and 2-3 set of forged 360 pistons that I saved for some stock eliminator builds. The pistons are good for 8-8.5:1. I like the idea of using lighter wrist pins. That's an easy purchase. The less reciprocating weight that I have the easier I'll feel about the crank.