View Single Post
Old 09-18-2010   #42
Pete
 
Pete's Avatar
 
Join Date: Dec 2003
Location: Chicagoland,IL
Posts: 2,667
Default Re: An enigma insues...

Quote:
Originally Posted by Paul Workman View Post
Pete, I see the valve lengths vary from 90-92 vs. 93-95. And, from that same link source, there is no difference in lifters across all years, if I'm reading it right. SO.....Where is the difference in the lengths being made up? Is there a difference in the base radius of the cam lobes, or seat depth in the heads, or does the lifter just suck it up?

P.

Paul,i don't think there is a difference in the heads since most have Birmal heads.
Since the later (93-95) valves are .020 shorter this would tell me the later lifters have .050 tolerance where as the early lifters have .030,i don't have documented proof on this but logic tells me this would be it,i don't think GM would make 2 different Birmal heads.
Basicly same happens when i use a regrind cam when regrinding a cam we take off about .030-.060 off the cam lobe depending on cam specs so if we minus .040 off the base circle then it only preloads the lifter .035 instead of .075 (stock)

Hope you guys are getting this,again if not ask away,there's no such thing as a dumb question.
Like i said this needs a visual much easier to understand,like sex. LOL

Pete
__________________
'91 #1635 PoloGreen 350 LT5
11.09 @ 129.27
11.04 @ 128.86
474RWHP 400RWTQ
http://www.youtube.com/watch?v=SFNFOhGGlR4
http://www.youtube.com/watch?v=ZlRIOMwaDYY
https://sites.google.com/site/peteszr1garage

Last edited by Pete; 09-18-2010 at 11:30 PM.
Pete is offline   Reply With Quote