What he said!
More to the point is that non-roller rockers are available from many
suppliers to a very good specification (Keith Dodd at Mini Spares Centre
makes the set of 1.5:1 rockers that I used for four seasons on my 1275
engines, other aftermarket units are available) and I use stock or prepared
stock Cooper S type rockers on the small bore A-series engines.
Yes, they do limit some other things on the motor. You probably wouldn't
get great life if you ran more than .450" or so lift, or more than 240 - 260
lbs peak spring load, but that's part of vintage racing! Those cams weren't
around back then, for exactly those reasons!
For what it's worth, I run about .400" lift, with about 200 - 220 lbs peak
spring load, and normally red-line at 7500 rpm. I've never broken a rocker,
bar those times when something else has broken first (rocker shafts took a
beating for a while, until we went to thick wall shafts).
VARAC does not allow roller rockers, BTW.
Brian
At 09:10 AM 1/18/99 -0500, you wrote:
>Howard,
> I'm not speaking in any official capacity, but in SVRA small bore
>production, we've been debating this for years...My opinion (from
>someone who routinely builds and brings half a dozen to a dozen cars to
>each event in a professional capacity) is that roller rockers should not
>be allowed.
Much more stuff that I agree with snipped...
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