In a message dated 1/20/99 12:07:39 AM, PaceCars@aol.com wrote:
<<Roller rockers are not a performance advantage for A series motors. What
roller rockers do is give you longer valve guide life, due to less side thrust
on the valves. Roller rockers are noticeably heavier than non-rollers, so if
you want to run high revs, non-rollers are probably superior.>>
-- that may be true IF there are no other changes to the motor. As I
understand it (and I am no expert on BMC motors) the roller rockers allow the
use of other parts which can greatly enhance performance.
<<Many of the fast guys in SCCA run non-rollers (Comptune sells his own
version of non-rollers) due to less valve train mass. >>
-- and how often do these "fast guys" rebuild the motor. I've heard they run
such radical specifications and high rpm that they install new crank bearings
every other session. I suppose if someone in vintage wanted to do that with a
non-roller motor and vintage legal parts (whatever that means these days), I
could not complain. I also would not envy anyone doing 3 or 4 engine rebuilds
every weekend as part of normal maintenance!
Sorry, I will not be convinced that roller rockers do not improve
performance
by allowing higher rpm and more aggressive cams and other performance parts.
Cheers, Doug Meis
(Of course it's easy for me bitch about roller rockers when I've got
overhead
cams AND a roller crankshaft)
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