Non-SE-R: GM OHV engines

[Rick Warkentien]

Two Words:
Valvetrain Mass...
In order to increase revs you want lower mass. With an OHC design you have a
cam, a follower of some sort (HLA, and rocker assembly in or case), and your
valves and springs.

With an OHV design you now have a follower (the lifter), a pushrod, a rocker
arm, and your valve and spring etc, More mass in the valvetrain =  lower
RPM. The higher momentum of the OHV design causes problems with vavle float
causeing unpredictable vavle operation at higher RPM's.

There are some interesting Rev-kits out there for OHV engines, specifically
the LT1 / LS1 series of engines. The help maintain contact with supplemental
springs etc.

I *think* the larger amount of torque off the line has to do with the 90*
between cylinders. Less angle between cylinders generally = less torque,
IIRC.

Anyway
Rick
Haveing a banana for breakfast.

> "Michael Jez" <93SER@attbi.com> wrote:

> >One thing OHV engines got over OHC engines is torque off the line, they
> >aint got shit for top end. Only thing that actually has balls for

> Why is this?  When the valves open, the valves are open, right?  Why does
it
> matter if it is a pushrod vs OHC actually doing the opening?

> -Bill
> >