ZR-1 Net Registry Forums - An enigma insues...

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- - An enigma insues... (http://zr1.net/forum/showthread.php?t=12589)

Re: An enigma insues...

If lifters are different for early verus late model years then there is a lot of documentation that is wrong in parts manual, catalogs, etc. Part number 17120991 shows for 90-95 everywhere that I can find.

Re: An enigma insues...

Quote:

Originally Posted by Paul Workman (Post 97654)

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?:icon_scra

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

Re: An enigma insues...

I would use the 2nd from left.
The 3rd from left sits deeper into the hole/bore and will not work with regrind cams unless you go with longer valves or stock cams.

Anyway i would go with 2nd from left and be done.

I thought Mellings were made in the USA at least the box says
Made in the USA, WTF

Pete

Re: An enigma insues...

When doing the upgrade to my motor this winter, I bought a new set of Sealed Power lifters from Rock Auto. Marc H had suggested that and they were less expensive than the Melling. However, when Pete tried insalling them with the regrind intake cams, there wasn't enough pre-load. I sent the SP lifters back and bought the Mellings. The heads are GVD heads with new valves, not sure whether new valve seats were cut but the Mellings are working just fine.

Re: An enigma insues...

Quote:

Originally Posted by Dynomite (Post 118863)

:cheers:

Dyno,

Pete may be able to provide pics. We didn't take any altho there was some difference between the Sealed Power and Melling lifters.

Re: An enigma insues...

Quote:

Originally Posted by Dynomite (Post 118863)

:cheers:

Yes,the ones Dom bought were the 3rd one from left.
Had the coating on the top and the plunger was different from the OE.
Never seen the 4th from left.

Pete