TRW piston identification..

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Apr 19, 2008 | 04:31 PM

89RsPower!

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Supreme Member

Joined: Apr 2002

Posts: 3,552

Likes: 5

From: New Jersey

Car: 86 Corvette, 89 IROC, 1999 TA

Engine: 350, 350, LS1

Transmission: 700r4, 700r4, T-56

Axle/Gears: 3.07, 373, 4.10

TRW piston identification..

Does anybody know how or where to look up TRW part numbers?? I just got a 350 off a buddy and I'm trying to get a rough idea of the compression ratio.. trying not to pull the heads off.. on the bottom they are marked TRW
and have a D on them with the number 262-96 under it.. any ideas?

Apr 19, 2008 | 05:37 PM

Air_Adam

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Joined: Oct 2002

Posts: 9,067

Likes: 1

From: Saskatoon, SK, Canada

Car: '83 Z28, '07 Charger SRT8

Engine: 454ci, 6.1 Hemi

Transmission: TH350, A5

Axle/Gears: 2.73 posi, 3.06 posi

Re: TRW piston identification..

What style pistons are they? If they are flat tops with 4 valve reliefs, then they are around 6cc "dish".

Apr 19, 2008 | 06:31 PM

89RsPower!

Thread Starter

Supreme Member

Joined: Apr 2002

Posts: 3,552

Likes: 5

From: New Jersey

Car: 86 Corvette, 89 IROC, 1999 TA

Engine: 350, 350, LS1

Transmission: 700r4, 700r4, T-56

Axle/Gears: 3.07, 373, 4.10

Re: TRW piston identification..

not sure, was hoping someone could tell by the number, havnt pulled the heads off, going to run it as is, just trying to get an idea is all. Hopefully I can borrow a bore scope off a friend to take a look.

Apr 19, 2008 | 06:48 PM

F-BIRD'88

Supreme Member

Joined: Sep 2001

Posts: 6,111

Likes: 53

From: Ontario, Canada

Car: 1988 Firebird S/E

Engine: 406Ci Vortec SBC

Transmission: TH-350/3500stall

Axle/Gears: 7.5" Auburn 4.10 Posi-Traction

Re: TRW piston identification..

The TRW/Federal Mogul piston part number is stamped on the top of the piston.
eg L2256F30 .030 .030 over forged flat top -6.10cc
H345P30 .030 over hyper flat top 1.54" compression height -5cc
(typical cast rebuilder flat top reduced compression height)

You need to know the piston/deck clearance @ TDC to get accurate cr numbers.

Apr 20, 2008 | 12:51 PM

89RsPower!

Thread Starter

Supreme Member

Joined: Apr 2002

Posts: 3,552

Likes: 5

From: New Jersey

Car: 86 Corvette, 89 IROC, 1999 TA

Engine: 350, 350, LS1

Transmission: 700r4, 700r4, T-56

Axle/Gears: 3.07, 373, 4.10

Re: TRW piston identification..

yeah I was hoping just to get a rough guesstimate.. figured the part # was probably on top but I saw those numbers on the buttom and was hoping maybe they ment something.. o well thanks for the help guys, guess I'll find out if/when I pull the heads!