Having followed some of the posts to this subject I thought I jump in here,
A ROLLER lifter is part of a ROLLER CAMSHAFT SYSTEM, which translates to
... you have to have a camshaft which is specifically designed as PART of the
SYSTEM.
Flat tappet type lifters (OEM Sunbeam) use a camshaft which has a narrow
peaked rapid ramp rise/fall lifting lobe shape,
ROLLER camshaft lobes are shaped more like soft eccentric circles.
And YES roller lifters MUST be prevented from rotating (or the roller part
would no longer be parallel to the lifting surface of its cam lobe and would
be damaged)
BUT ROLLER camshaft conversions are done frequently in the world of HIGH
PERFORMANCE engine building and the KITS are relatively CHEAP and EASYish to
install.
The difference HERE is that there are a lot of AFTERMARKET MFG's producing
"SPEED PARTS" for CHEVY, FORD, and a few others, but I am not aware of anyone
making the same for Sunbeam's.
Roller TIPPED rocker's ARE possible on just about any pushrod engine if you
have DEEP pockets, and a shop with machining exp.,(like mine), I have done a
few NON SUNBEAM/NON MFG. SUPPLIED conversions in my shop.
BUT for the very, very SLIGHT gains in performance and reduced valve stem
wear, the procedure is USUALLY LIMITED to racing applications.
In the past I have spoken with Camshaft blank producers and Finishing mfg's
in reference to producing lines of PERFORMANCE Cams for ORPHAN/NON-MAINSTREAM
engines and well you know,
"Design spec.'s, $$$... and Minimum run lots of a couple hundred pieces...and
more $$$...and MAYBE if you can presell 100 CAMS @ $500+EACH..."
My .02
Ron
CRUISERS CLASSICS LTD. (Chicago area)
(formerly Kevron Auto Care Corp., Willowbrook, IL)
In a message dated 06/01/01 8:52:21 AM Central Daylight Time, wiencek@anl.gov
writes:
> I posted a reply to your previous message before I saw this message. Would
> you explain more clearly for us engine challenged people what you mean by "
> and the pushrod would hit the rim of the lifter"? Other engines must
> overcome this problem to use roller lifters or am I missing somthing?
Thanx.
>
> On 6/1/01, Jarrid Gross <jarrid_gross@earthlink.net> wrote:
> Jim,
>
> Any roller lifter/follower Ive seen requires that the lifter
> protrude out of its bores (at all times), to allow an inter-connecting
> strut that connects adjacent lifters, and prevents the rollers from
> rotating.
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