triumphs
[Top] [All Lists]

RE: Over my head with valve train noise

To: <triumphs@autox.team.net>
Subject: RE: Over my head with valve train noise
From: "Randall Young" <ryoung@navcomtech.com>
Date: Thu, 15 May 2003 15:43:19 -0700 FILETIME=[61EC1610:01C31B33]
> After 10 years of restoration work, I finally managed to drive my TR4A
> to the end of the block and back yesterday.  No hood, interior, tranny
> tunnel, guages, etc., etc., but it still made it.   This is also the
> first time the rebuilt engine has been run.
>
> One of the first things I noticed (after I got the exhaust to work) was
> the incredibly noisy tapping from the valve train.  First step was to
> check rocker clearances; all are at 0.010" cold.  Now is where it gets
> tricky...
>
> The head is shaved 0.080".  I'm also using a shim steel head gasket from
> Ken Gillanders at BFE, as well as a performance cam from him (don't
> remember the specs off the top of my head).

Dave, a couple of things :

First, get the specs for the cam, as many performance grinds call for
clearances larger than .010"

Second, are you sure the noise isn't just normal cold-engine valve clatter,
made louder by the absence of hood and trans tunnel ?

Rocker geometry on a rocker shaft engine is fixed by the height of the
pedestal and the length of the valve.  Contrary to popular wisdom, I believe
you only need shorter pushrods if your adjusters don't have enough travel to
set the clearance to spec.  Otherwise, all you do is screw in the adjuster
more to match the shorter pushrod, and the rocker/valve geometry does not
change.

This of course is not true for many American engines, where the pivot point
is the adjustment.

Ken's valve springs should have plenty of travel, but checking for bind is
still a good idea.

Randall

///  triumphs@autox.team.net mailing list
///  or try  http://www.team.net/cgi-bin/majorcool
///  Archives at http://www.team.net/archive


<Prev in Thread] Current Thread [Next in Thread>