Non-SE-R: GM OHV engines (better late than never)

Tim Rogers timrogers@charter.net
Mon, 2 Dec 2002 19:03:31 -0600


Bruce.Hearn wrote:

>>Au contraire, OHV **CAN** run fast...with solid lifters.  Neckars run 8000
rpm regularly and can go as high as 9k, but rod life falls drastically. All
the really hot muscle cars had solid lifter engines, though they didn't
spin much faster than those with hydraulic lifters, mainly because Detroit
still used heavy rods and pistons.<<

While that is very true Bruce, I have never seen a *factory* OHV motor
redlined at over 7000 RPM's (with solid lifters, I'm sure.)
To keep it "apples to apples,"  we've seen our motors redlined at 7500,
Integras at 8100, and S2000's at 9000 from the factory.
When you go to a full race version of a production motor, a la NASCAB or
BTTC, the rev limits go to 9000 for pushrods (as you stated.)  Our motors
OTOH are limited to 9500 by the BTTC's sanctioning body's rules.  I'm not
sure what valve train mod's are done to Toyota's 4AGE when they are prepared
for Formula Atlantic use, but they rev over 10,000 rpm.
Then when you get outside the production-based arena, we get CART and F-1
engines revving over 18,000, and OHV motors just getting ignored.

Tim Rogers
-93 NX T-top -needs wiring work
-91 NX - Racecar-to-be
-75 Silverado - Rusty Tow Beast