I was wondering if anyone had used Rebco Machine or someone else to lighten a set of pistons? I ordered a set of Hemi pistons from Diamond, but they list the weight at 800g. Mike Bogina recommended I use Rebco rather than get Diamond to lighten them. He has used them on his SS Hemi engines.

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

Rebco is undoubtedly nice, but Diamond can get the weight way down, and I'm sure for cheaper. I'd feel better about the manufacturer doing the work. They'll cut the underside to match the top profile, and cut some out of the pin boss. Much more than that and you're splitting hairs. Too much lightening can be a bad thing, unless you're a class racer. We've done lots of work around lightening, and there is a point you cross where the power goes the other way because the piston starts flexing, and either cracks, or just starts losing seal from flexing around the lands. Another thing that hurts is going too light on pins. Pins flex too and if the piston is going to be really light sometimes you have to go heavier on the pin to counteract the loss of strength in the piston. that's why I like the maker to do it. No doubt there's good power in going light as you can, but knowing right where the break point between weight and power loss is can be expensive to find.

I Know very little but I do build my own motors. Both Diamond and JE could improve their sales by using more experienced people to take the orders when even a cheap Hemi is 30k. I have used both, but now use CP. They are very knowledgeable, speak Mopar extremely well, and their pistons look like jewelry. Everyone running a fast NASP Hemi is looking for RPM and bearing life.

All my Hemis have CP pistons for that very reason. Diamond is also a great piston, but CP knows how to listen and make what YOU need for YOUR Mopar. Either Dave, or RC, at CP are good guys for Hemi piston advise.

They made me a 16:1 4.565 bore HEMI piston under 600 grams, that has good stability as well.

You're under my weight and I hope it's cause it's a millenium piston, or I'm gonna be jealous. I hope I'm lucky enough to see your car in person this year. Mine's all apart right now being freshened and K-member is back east. Should be running by May.

Rebco and Pattersons have been lightening pistons for many years now for many, many Comp Elim racers. I know Rick Liuzzo (Domino1609) has used them in the past.

Haven't seen any of the lightened Diamond Pistons first hand, but a friend has ordered a set for his 300 inch wedge Chevy. I will be interested to see them
AL...

We'll I'll say this about Diamond VS CP at least... we are now WD with both & have used a bunch of both all in Customs.

My impression after having Diamond do a couple sets of their "Maximum lightening" package..... it's pretty.... but they could go alot further especially in the strutting webbing & skirt ribbing. CP definitely without a doubt makes a lighter piece when doing a max lightened piston.... My impressions are Diamond lightens, but stays very "safe" with their max lightening.... CP just goes hog wild... JE very similar to CP in their lightening. CP will pull alot out of the "belt" area & their forgings are much lighter in the way they rib the wristpin to skirt on the "X" style forgings.

On a basic custom I actually did two customs in the exact same specs, one from Diamond, one from CP exact same dimensions for 2 identical circle track motors.......Flat tops, same reliefs, same ring pack, same pin size/width, same bore, both full round skirts.... Everything the same, NO lightening options... Off top of my head the Diamond was like 510 grams, the CP was like 475. I was amazed by the difference in weight...

The CP's cost more Almost everything I do anymore has Diamonds in it since the Jan 2008 CP price increases. Unless I need that lighter weight, Diamond can get me a piece just as strong & accurate, for less $ & most importantly do it quicker. CP is nice with the Expedite stuff when you need it real real fast but $300 for one week expedite is harsh. Diamond can usually knock customs out in 10-15 days depending on how busy they are. If you don't expedite CP's... in Winter you can be waiting a good 4-5 weeks.

Thanks for the replies. I also e-mailed some friends and everyone had good things to say about REBCO if they were familiar with them. I also heard that Patterson was using them for Comp eliminator. The Diamond pistons I got were off-the-shelf pistons that they had marked down 50%, so they weren't trick custom pistons like you guys are running. This engine will be more of a dyno mule to test intakes, cams, etc., so a maximum lightening effort isn't necessary. I'd rather have something durable, but reasonably light. I wish I'd thought of having Diamond lighten them up when I ordered them, but didn't think about it until I talked to Mike and found out how light his are. I'll get Diamond and REBCO to give me a quote and see what they come in at. I think I'll have the block bored and honed and put the pistons in for piston-to-valve clearance check before I send them out for lightening.