PRO requires the same valves and port configuration ONLY. Other than
that your are UNLIMITED (according to the rule book). So if you kept 2
valves, and the ports were the same bolt pattern as stock, you met the
intent of the rule book. Look at some of the aluminum heads running in
PRO. Everything from $4,000 WeldTek to AFR, Brodix, Dart, etc.
Obviously, a peek at the port internals would not even be close to
stock! They are LEGAL.
So lets say you want to shrink and engine and now need more RPM but are
limited by the stock config. The question was asked what would a DOHC
or SOHC do for you if it was NOT a hemi configuration. Hmmm, if you put
a single cam on the top of a 23 deg head and ELIMINATED, push rods,
rockers, and very heavy lifters, what would that do for you?
BTW, in my memory of the SBC over the last 50 years, there have been two
(maybe more?) attempts at a DOHC conversion for the SBC. The latest
attempt was only a few years ago and they sold for about $10K (less than
the Ferguson ARDUN set-up). The dyno sheet was not too favorable for
that set-up but some of those are still floating around. -Elon
-----Original Message-----
From: John Beckett Sent: Monday, January 03, 2005 7:56 AM
(1) Can't do that in a /PRO class. Gotta have stock type heads.
(2) If you took a stock 23 deg Chevy head and added overhead cams
(snip...)
(3) I've always thought the OHC allowed you to have a hemispherical
combustion area with the valves at 90% to where they are on a rocker arm
head. That gives better combustion and better flow. Bob in connecticut
|