-----Original Message-----
From: n197tr4 <n197tr4@cs.com>
To: tedtsimx <tedtsimx@bright.net>; fot <fot@autox.team.net>
Sent: Sat, Jul 9, 2011 12:32 pm
Subject: Re: [Fot] 1500 Spit rockers
----Original Message-----
WHAT TED SAID. SEE BELOW MY NOTE.......................
-----------------------------------------------------------------------------
---------------------------------------------
It would seem that Harland Sharp and a hardened rocker arm shaft would likely
satisfy most applications while being cost effective, as Ted says.
Harland Sharp has a comprehensive website....it also lists most of your
favorite distributors and most of the distributors have pricing so you can go
shopping on price.
I cant speak to geometry.
One FOT is very satisfied with his Harland Sharp and hardened shaft.... and
looked closely at the geometry. This is on a TR6.
Another FOT seemed concerned about the geometry for the TR3/TR4 from HS. He
was a mechanical engineer, but it is only hearsay in either case.
Somebody else out there may have studied this in depth and has come to a
factual conclusion.
I'd be interested in more information. I have a set of Harland Sharps on the
shelf I have never used. Might be cool on the AMBRO or on my street TR3A.
ANYONE?
Joe A/
From: Ted Schumacher <tedtsimx@bright.net>
To: fot <fot@autox.team.net>
Sent: Sat, Jul 9, 2011 11:48 am
Subject: Re: [Fot] 1500 Spit rockers
Joe & List. We sell only Harland Sharp and have for 20 years. Good
product, tons of experience (they were the first ones to develop a
roller rocker for small block Chev circa 1960) and great tech support.
Rockers have a feature that oils both the rocker tip and the push rod
cup. We supply these with bronze rocker shaft bushings. You will see
roller rockers advertised with needle bearings for the rocker shaft.
There are some issues with needle bearings. #1- oil has a tendency to
"fall out"of the needle bearings due to needle bearing design. This is
fine if you are pulling rocker assembly for inspection regularly (as in
every week-end). #2 - since the rocker arm rotates only a small distance
around the rocker shaft, and needle bearings are very hard by design,
this create the potential for severe shaft wear. Needle bearings are
great for supporting a spinning shaft, such as internal gear box parts,
but they ride in lubrication all the time and they are supporting the
entire shaft, not just a small area of the shaft. If you have an engine
that lives at high revs, good size rocker shaft diameter, excellent
oiling and checked often (smallblock Chevy sprint car engines, NASCAR,
etc) needle bearings will work (but so does their budget for tear down
and rebuild). Extremely high ratio rockers unless coupled with very low
rate valve springs are death on the valve train Ted
_______________________________________________
fot@autox.team.net
http://www.fot-racing.com
Donate: http://www.team.net/donate.html
Archive: http://www.team.net/archive
Forums: http://www.team.net/forums
|