CRG Discussion Forum
Welcome, Guest. Please login or register.
Did you miss your activation email?
October 20, 2014, 08:05:49 AM

Login with username, password and session length
Search:     Advanced search
Welcome to the CRG Discussion Forum!
Forum registration problems: Make sure you enter your email correctly and you check your spam box first. *Then* email KurtS2@gmail for help.
105519 Posts in 12322 Topics by 4751 Members
Latest Member: Blakep54
* Home Help Search Login Register
+  CRG Discussion Forum
|-+  Camaro Research Group Discussion
| |-+  Decoding/Numbers
| | |-+  SB Piston GM part #
« previous next »
Pages: [1] Print
Author Topic: SB Piston GM part #  (Read 5053 times)
Chris_Pisane
Member
***
Posts: 61


View Profile
« on: December 09, 2007, 01:29:57 PM »

Hi, I have a set of used pistons I got many years ago that I always assmumed were 69 302 pistons since they came with a 69 302 crank and pink rods. The part # on the underside of piston appears to be a GM #3927172 TRW,they are domed. I checked the fact book and thats not the right one for 69.

I checked my chevrolet by the #s and they dont have part #s listed for pistons.

Any Help?

Thanks.
Logged

Chris Pisane....Fathom green 69 z/28 ,Lemans blue 69 JL8 Z/28 http://cpisane.photosite.com/
Steve68
CRG Member
*****
Posts: 506


View Profile
« Reply #1 on: December 09, 2007, 01:50:43 PM »

Chris, can you double check that last number (2) to make sure you read it correctly?  Thanks.

Steve
Logged
Chris_Pisane
Member
***
Posts: 61


View Profile
« Reply #2 on: December 09, 2007, 02:01:35 PM »

3927172. There is an L under that number

Thanks
Logged

Chris Pisane....Fathom green 69 z/28 ,Lemans blue 69 JL8 Z/28 http://cpisane.photosite.com/
JohnZ
CRG Member
*****
Posts: 4121


View Profile Email
« Reply #3 on: December 10, 2007, 02:01:48 PM »

3927172 is correct - that's the FORGING NUMBER, not the part number; the part number won't appear anywhere on the piston. That raw forging was finish-machined into several different PART numbers for the standard bore and oversizes.
Logged

'69 Z/28
Fathom Green
CRG
Chris_Pisane
Member
***
Posts: 61


View Profile
« Reply #4 on: December 10, 2007, 06:37:51 PM »

OK, lets see if I get this straight. It is a factory 302 piston,right?

The TRW forging  nuimber is  like many GM part #s of that era,even the same number of digits, thats is why I assumed it was a GM  part number.

I have some 70s vintage overbore pistons and they actually have 2210A stamped on them,these dont.The forging # appears to be 186-99.

I knew John Z would have the answer,correct me if I misunderstand. THANKS!!!
Logged

Chris Pisane....Fathom green 69 z/28 ,Lemans blue 69 JL8 Z/28 http://cpisane.photosite.com/
JohnZ
CRG Member
*****
Posts: 4121


View Profile Email
« Reply #5 on: December 11, 2007, 11:38:47 AM »

L2210 is the TRW 302 aftermarket finished piston number; the raw forgings TRW supplied to GM for OEM use had the 3927172 GM forging number on the underside of the crown; the final cam-ground machining of the pistons in production was done at the GM engine plants.
Logged

'69 Z/28
Fathom Green
CRG
69z28rsbilly
Member
***
Posts: 49



View Profile
« Reply #6 on: April 25, 2009, 12:04:36 AM »

I have some TRW pistons with casting # 3927172 on the bottom side and 3927173 stamped into the top. They look to be standard and never used.
 Is there good way to tell if the pistons have been used or not ?
Logged

X33 72 72 RS
X33 71 71 RS
X33 71 71
Jerry@CHP
CRG Member
*****
Posts: 1445



View Profile Email
« Reply #7 on: April 26, 2009, 08:54:18 AM »

One small note, all of the over the counter TRW pistons use the thinner piston rings.  Keep that in mind too.

Jerry
Logged
Pages: [1] Print 
« previous next »
Jump to:  

Powered by MySQL Powered by PHP Powered by SMF 1.1.19 | SMF © 2013, Simple Machines Valid XHTML 1.0! Valid CSS!
Page created in 0.069 seconds with 17 queries.