Re: Final drive and high revs...

[<IHMagellan@domain.elided>]

Something to keep in mind.......Aside from the valvetrain inadequacies, the
issue with over revving is fatigue.  You're not going to see catastrophic
failures from one accidental journey to 5000 rpm.  But when it survives the
first trip, don't get the idea that 5000 rpm is OK.  Keep doing it and there
will be damage.  I don't know what the weak link is in an IH.  I've heard
things about cracks in 345 cranks through the years.  Don't know if there's
any merit to that.

I've seen 8000 rpm out of a 396 in a Chevelle SS before.  It had a cast crank
and factory balance job.  My buddy who owned the car was doing a burnout and
missed second gear.  The linkage clicked like it was engaged, but it wasn't.
8000 rpm came before he could get off the throttle.  He shut it down and we
sat there without saying anything for about 10 minutes while we mustered up
the courage to restart it.  Amazingly, no damage was done, but he left the
tach redline set at 5500 rpm.

Jerry Muncie

In a message dated 98-08-12 19:02:36 EDT, you write:

<< This isn't like overreving another engine where you risk actaully
 blowing some part of the valve train. The weak link in the IH is the
 valve springs and if you exceed their capabilities, the resulting valve
 float will act as a kind of "governor" for engine speed. >>