View Single Post
Old 09-19-2016, 12:39 PM   #42
crazycasey
Senior Member
 
Join Date: Jul 2011
Location: Cotati, Calif.
Posts: 110
Default Re: Need help from the flathead gurus...? Valve clearance issue

Quote:
Originally Posted by Bored&Stroked View Post
The lifters should have a slight convex shape to the bottoms of them - they should not be surfaced to a flat state. It sounds like he has a set of used lifters - which could explain the large differences in length.

Lapping: This procedure can't be used to tighten up your clearances - it is only to fine tune the sealing surfaces, not anything more.

As many noted: I'd be suspect of the whole valve train setup:

a) Spring heights need to be correctly setup - such that you have the correct amount of pressure on the valve seats. Using Chevy valves makes this a bit more difficult - but there are plenty of ways to deal with it - depending on the combination of lifter types/lengths, shims, retainers, lash-caps, keepers, etc..

b) The lifters should be newly resurfaced - or new. Unless the bottoms of the lifters are practically new (and convex) - you probably do not want to reuse them "as is". I would not - it is not worth saving a few bucks in this area.

c) Machine Shop: The comment about "not being hard enough" would worry me. Seems like a way to sell you more parts and/or work - has nothing to do with Chevy valves. Truth be told, the stem ends have a lot more pressure and wear tendencies with a rocker arm, than a direct tappet on a flathead.

If it was me - I'd find a much better machine shop and ensure that everything gets done by experienced flathead folks.

Punting: If you have the capabilities and equipment to measure and set spring heights, you may be able to use the same valves, same guides and change the lifters to adjustables . . . but that is a big assumption on my part. It is really important to know what your current spring heights/pressures are - before thinking of that approach.

Best of luck . . .

B&S
Dale,

Your post from the other site (it's a GOOD ONE):

http://www.jalopyjournal.com/forum/t...inions.420484/

I think THAT's my answer, with the turned down Comp Retainers and a new set of oem non-adjustable lifters to bring my clearances back in spec. Either that, or the Comp adjustable tappets, as they seem to be short enough to use Chevy valves without removing a TON of material. I just have no clue as to their quality, and whether or not they're heavy enough to warrant more valvespring.

Where's the best place to buy a set of Zephyr springs? Red's!?
crazycasey is offline   Reply With Quote
Sponsored Links (Register now to hide all advertisements)