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85boostbox
03-03-2013, 03:49 PM
Anyone ever run them? If so do you know or does anyone know what C/R it gives with g head setup. Can get a really good deal on them and I think it would make a boosted setup fun.
cordes
03-03-2013, 11:32 PM
I think they're close to 10:1 with flat top pistons and a G head. I would have to check my FWD performance secrets book to be sure though. Premium fuel only with boost for sure.
OmniLuvr
03-04-2013, 03:33 AM
I ran 14.7 psi on 91 with my t3 piston g-head motor, s60 turbo, stock head, intercooler, and turbo roller cam. I felt like it could have handled more but I didn't want to risk it without knock detection. I think the comp ratio is 10:1 with the swirl combo, making it closer to 9.5:1 with the g-head I think.

What kind of boost are you shooting for?

If I could find flat top forged pistons with valve reliefs for a deal, I would buy them right now and build another motor with them. But I think the deciding factor would be how much are you going to shave the head? If you shave the head the valves will protrude more into the cyl, and the comp ratio will b fairly high.
85boostbox
03-04-2013, 08:17 AM
There the TRW forged flat tops. So true flat tops.
wallace
03-04-2013, 08:37 AM
Are the TRW's still available or are these NOS you have found? I'd be interested in a set if they are something you can buy off the shelf.
85boostbox
03-04-2013, 09:52 AM
No these were used flat tops still in real good shape. No scuffing on the sides and all the rings were free. They use .901 wrist pins.
contraption22
03-04-2013, 04:44 PM
Would make a fun car with low boost, or normal/high boost with race gas or E85.
85boostbox
03-04-2013, 04:47 PM
That is what I was thinking. And I was thinking of a e85 setup. Just don't know if there is any e85 stations close to me.
85boostbox
03-04-2013, 04:51 PM
And that is also why I would do a ghead setup as well. Valves don't go as far down as a swirl.
wallace
03-05-2013, 08:53 AM
That is what I was thinking. And I was thinking of a e85 setup. Just don't know if there is any e85 stations close to me.

I'm getting my e85 from Phillips petroleum on 17 in Gloucester Point. Not too far away from you I don't think. You'll have to pay a toll to cross the bridge.
85boostbox
03-05-2013, 09:24 AM
Huh i didnt know there was e85 there. There is also e85 at the naval base which is about 2 miles away from me.
wallace
03-05-2013, 09:33 AM
Yeah, there's e85 up here on base but they will not let civilians on there just to get e85. I'm using a 100 gal. transfer tank to get it and I've got 2 55 gal barrels in the shop I store it in. That's the only issue with using it is you have to come up with a way to keep a supply on hand. I tried to get a local fuel company to deliver me some but that went nowhere. Good luck.
85boostbox
03-05-2013, 10:00 AM
I am a government contractor so I can get on any base LMAO
wallace
03-05-2013, 10:12 AM
You've got it good then almost every base I know of carries it.
85boostbox
03-05-2013, 10:53 AM
Yea i found that out cause i looked it up online.
wallace
03-05-2013, 10:59 AM
Yep using the e85 station finder? When I first started using the e85 the only two places around I could get it was Charlottesville and some place in Northern VA. I never went to the Northern VA store I always went to C-ville....much nicer drive.
85boostbox
03-05-2013, 11:28 AM
Lol. Yea even if i cant get it i have enough military friends that could get it for me. You know there is this local fuel place. Maybe they might deliver to you or know of someone that might. I would have to look them up.
GLHS60
03-05-2013, 02:27 PM
I have a couple if sets of new, forged, flat top pistons. One set is TRW and the others are M.P., but I think the're TRW also. They are long discontinued but I could get the part #'s if you're looking for a set.

Thanks
Randy
.



Are the TRW's still available or are these NOS you have found? I'd be interested in a set if they are something you can buy off the shelf.
Reaper1
03-06-2013, 12:04 AM
The TRW crowns are SUPER thick making them much heavier than they really need to be. To combat this you can do a few things: run a longer rod, have the piston stick up out of the bore, then have them milled down to be flat with the deck. Or, you could simply mill them down on the stock rod, but that will lower the CR. You could also deck the crap out of the block and then mill the pistons down to the deck, but I'd be careful with that option with a turbo application.

I can't remember the exact dimension of the crown thickness on those, but I bet if you measure a stock turbo piston vs. the TRW you'd be amazed. The REALLY good part? When you mill those pistons down, they get even lighter!! That's a GOOD thing!!
wallace
03-06-2013, 08:34 AM
I have a couple if sets of new, forged, flat top pistons. One set is TRW and the others are M.P., but I think the're TRW also. They are long discontinued but I could get the part #'s if you're looking for a set.

Thanks
Randy
.

Yes please that would be great.
GLHS60
03-08-2013, 12:19 AM
The TRW part # for 2.2 flat top forged is L2502.

The M.P. part # for 2.2 forged flat tops is P4286588

I'm pretty sure there are some other #'s for M.P. 2.2 forged flat tops also.

The last time I ordered a set of M.P. forged pistons, years ago, what came were hyperutectic so this might be something to watch out for if buying some NOS M.P. pistons.

Thanks
Randy




Yes please that would be great.