I use an engine shop that does mostly big V-8s. Saw the same thing in a
drag motor that was in there, with the tie bars between the lifters. Design
of the motor was different in that the tops of the lifters were exposed and
easy to tie together. Don't know how I could do that on my GT6 without big
mods?
----- Original Message -----
From: "EDWARD BARNARD" <edwardbarnard@prodigy.net>
To: <fot@autox.team.net>
Sent: Friday, August 13, 2004 7:44 PM
Subject: Engine question
> Lister's:
> Those of you who know me know that I've come up with some
real hair brained ideas at times. Well this question may be another one of
those way out ideas. Y'all be the judges. A couple of months ago I was
working on a "blown" 496 Hemi for a friend (by the way, this is not in a TR,
it's in a "70 Superbird). I am of the opinion that engines are pretty much
the same, at least in principle. Well, come to find out this has what they
call roller cams and lifters. Not rockers mind you. The lifter has a set of
roller bearings in the surface which contacts the cam lobe. The cam lobe is
ground with the same amount of lift as a normal cam for this car, but the
ramp to fully open is extremely steep and the open duration is very long.
The roller bearings are there to handle the extreme loads placed on the
lifter by the steepness of the lobe.
> The idea with it is to decrease the amount of time the valve
is moving between closed and open, and leave it fully open longer. Sounds
like a great idea to me! There are other considerations to take into
account. With this setup they don't want the lifters to rotate for obvious
reasons, so they place a pivoting bar between every two lifters to stop
this. Kinda hard to describe without a picture, but a needed evil that I
think could be substituted by something else.
> Anyway, my question is; has anyone ever seen this setup
before? Tried it on one of our TRactor motors before? Think I'm crazy?
(don't all raise your hands). It just strikes me in my idle time that we
send piles of money for roller rockers which look cool but gain us very
little h.p., while roller lifters may gain more. By the way, I'm told this
is twenty year old technology. My friend is suppose to give me a used roller
lifter to play with so I'm interested in your ideas. Thanks - Ed
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