Questions on 71' 455

Trouble · 01-09-2008, 09:27 AM

Does anyone know what the compression is on a factory 71' 455?

W30post · 01-09-2008, 12:25 PM

IIRC it was 8.5 to 1 down from 10.5 in 70. Be aware that a set of Felpro head gaskets on that motor can take it to almost 8.25 to 1.

Olds64 · 01-09-2008, 02:20 PM

Also don't forget that when you rebuild the engine compression will be affected by pistons, and how much you mill the heads and deck (which changes combustion chamber volume).

01-09-2008, 09:27 AM	#1 (permalink)
Trouble Junior Member Join Date: Jan 2008 Location: Houston, Tx. Posts: 3	Questions on 71' 455 Does anyone know what the compression is on a factory 71' 455?

01-09-2008, 02:20 PM	#3 (permalink)
Olds64 Landyacht Club President Join Date: Jul 2007 Location: Lawton, OK Posts: 1,811	Also don't forget that when you rebuild the engine compression will be affected by pistons, and how much you mill the heads and deck (which changes combustion chamber volume). __________________ "Some men are Baptists, others Catholics. My father was an OLDSMOBILE man." Ralphie Billingsley A Christmas Story 1983 "We rei-eign, supreme, ooooh god! Burrito supreme, and a chicken supreme, and a CUTLASS SUPREME!" Tenacious D 2007

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01-09-2008, 12:25 PM	#2 (permalink)
W30post Member Join Date: Oct 2007 Posts: 33	IIRC it was 8.5 to 1 down from 10.5 in 70. Be aware that a set of Felpro head gaskets on that motor can take it to almost 8.25 to 1.