[T3] type3-vwtype3.org Digest, Vol 46, Issue 21

Daniel K. Du Vall dduvall at 1peter4-10.org
Thu Jul 24 07:23:53 PDT 2014


I have always run 0 tolerances with the CrMo. You adjust them till snug and the back them off till they turn with little to no force. It can make for a rough cold start but once warmed up things check out nicely.  This is how I was told by Dan Lawson at Competition Engineering in PHX Arizona to do them. I ran an Engle 120 cam with duel springs and stock rockers with a kit to remove the separation clips for solid retainers. 

Daniel Du Vall

-----Original Message-----
From: type3-vwtype3.org [mailto:type3-vwtype3.org-bounces at lists.vwtype3.org] On Behalf Of Jim Adney
Sent: Wednesday, July 23, 2014 11:48 PM
To: type3 at vwtype3.org
Subject: Re: [T3] type3-vwtype3.org Digest, Vol 46, Issue 21

On 23 Jul 2014 at 14:25, Fiesta Cranberry wrote:

> He is wondering if the problem could be caused by using the wrong 
> pushrods.  He said he used chromoly, not aluminum, and he thinks they 
> may have pounded the lifters too hard instead of flexing.

The best pushrods to use in most engines are the OE style, with alum bodies. This is because the thermal expansion is a better match to what the cylinders do as the engine warms up. The cylinders get much hotter, but the alum pushrods have a larger expansion coefficient, so they match pretty well. The CrMo ones don't. 

The steel pushrods may be a better choice for hi lift cams and double valve springs in very high performance engines, where the greater strength of the CrMo pushrods may lend an advantage, but you'd have to do your own research on what the cold valve clearances should be 
once you change any of the material in the valve train.   

Whether this could have caused your problem, I really don't know. 
You're on really uncertain ground here.

--
*******************************
Jim Adney, jadney at vwtype3.org
Madison, Wisconsin, USA
*******************************

_______________________________________________
VWType3.Org mailing list - type3 at vwtype3.org http://lists.vwtype3.org/listinfo.cgi/type3-vwtype3.org
Contact gregm at vwtype3.org if you need help with the list.



More information about the type3-vwtype3.org mailing list