FE-FC Holden Discussion Forum
August 02, 2021, 11:03:26 PM *
Welcome, Guest. Please login or register.
Did you miss your activation email?

Login with username, password and session length
News: The FE-FC Holden Car Club of NSW are proud to host the 19th FE-FC Holden Nationals. Check out the announcement video for more.
 
   Home   Help Search Calendar Login Register  
Pages: [1]   Go Down
  Add bookmark  |  Print  
Author Topic: Piston markings  (Read 86 times)
Pahs59
nsw-club
Junior Member
**
Offline Offline

Model: FE
Posts: 72

Throw nothing away leave that for your children


View Profile
« on: July 18, 2021, 06:30:26 AM »
0

Hi
I have two sets of pistons with the numbers 7406474 stamped on top but one set also has LO stamped just above the numbers..can I mix these to make a set
Logged
my8thholden
nsw-club
Senior Member
****
Offline Offline

Model: FC
Posts: 638



View Profile
« Reply #1 on: July 18, 2021, 07:17:06 AM »
0

Pah ..If the part numbers stamped on all pistons is original factory GMH numbers then they must be the same , usually any changes , improvements etc made over time usually brought about a change of part number , do they look the same , do they weigh the same , are all ring groves identical ? are they dimensionally identical ? The LO mark ? , not sure , is it also original mark ? If they marry up in all aspects ,then I would use them . There can be small changes made at the factory when testing revealed a need that does not bring about a part number change , example extra oil drain hole/s in the oil ring land , change of piston pin circlip, these improvements where usually covered by a bulletin , 60 odd years later you can only deal with what is in front of you , and seek information ,like you have ..keep well Vern .
Logged

these days i'm half as good for twice as long
Pahs59
nsw-club
Junior Member
**
Offline Offline

Model: FE
Posts: 72

Throw nothing away leave that for your children


View Profile
« Reply #2 on: July 18, 2021, 07:57:53 AM »
0

Thanks Vern
Iíve checked both pistons with the verniers at the top, at the Gudgon pin and at the bottom and there the same measurements, sat them side by side and heights are the same as well.. the dimple in the middle of the piston with the 7406474 number only but the 7406474 LO piston has the dimple about 1/4 of an inch from the edge of the piston head facing forward.only thing I havenít checked is the ring grooves like you mentioned to see if there are any extra holes or any small differences..Iím only needing the one piston as when I pulled the motor down every compression ring was broken and on one piston a piece of broken ring worked itís way up under the other piece of ring and spread the ring groove,straight away I figured the bore would be knackerd but luck was with me thereís not a mark in it
Thanks for the info Vern
Logged
Pages: [1]   Go Up
  Add bookmark  |  Print  

Share this topic...
In a forum (BBCode) 
In a site/blog (HTML)

 
Jump to:  

Powered by MySQL Powered by PHP Powered by SMF 1.1.21 | SMF © 2015, Simple Machines Valid XHTML 1.0! Valid CSS!
Page created in 0.041 seconds with 19 queries.