Did GM use the same rings for NA and turbo 109's?

[Mike T]

This has my curiosity up because all of the info I can find shows the same part number 25527543 for both.
If so what was the OEM material...moly, cast, ext.?

Crossover numbers

GM 25527543
SEALED... E369K
GM 1240955

 

[TTipe]

This has my curiosity up because all of the info I can find shows the same part number 25527543 for both.
If so what was the OEM material...moly, cast, ext.?

Crossover numbers

GM 25527543
SEALED... E369K
GM 1240955

GM did not use the same ring pack on the NA & Turbo. I believe 1 & 2 compression rings were ductile iron to avoid ring micro-welding.

 

[Mike T]

Thank you for the info.
Been digging around trying to find the absolute cheapest rings for a extreme budget rebuild. Knowing the stockers took a fair amount of abuse thought maybe the e-369k from Summit for 48.00 were the ticket. They crossed over to OEM part number from GM and also the specs looked decent (moly) although ductile or nodular iron was not part of the description.


Bore (in): 3.800 in.

Bore (mm): 96.520mm

File Fit: No

Top Ring Included: Yes

Top Ring Thickness: 5/64 in.

Second Ring Included: Yes

Second Ring Thickness: 5/64 in.

Oil Ring Included: Yes

Oil Ring Thickness: 3/16 in.

Oil Ring Tension: Standard

Gapless: No

Top Ring Material: Iron

Top Ring Facing Material: Moly

Second Ring Material: Iron

Second Ring Facing Material: Cast iron

Oil Ring Material: Stainless steel

Quantity: Sold as a set.

 

[earlbrown]

You can't really trust part number X-overs anymore. After 30 years, numbers get superseded and combined.


I wouldn't be surprised if a few different rings packs turned into one part number over the years.


The only way to know for sure would be to get a parts fiche from the late 80's and compare it between cars. ....and even then it might not be 100% accurate. Sometimes the factory has access to parts for builds that even dealerships don't have access to.