Ferrari Mailing List: Re: Well, that just about sums it up (with lots of TECH and Ferrari Content, but no opinions added)

[Hans E. Hansen (FList]

For FG:  The NASCRAP guys routinely turn over 9000rpm.  Not
exactly stock engines, but they are pushrod.  Drag racers go
much higher.

Just $.02, some a bit off topic:

1.  I was talking several years ago to Jim Mennaker (sp?  I have his
business card around here somewhere.....), who was in charge of
powertrains for Corvette and some other GM vehicles.  I asked why
they were developing a new (this was in the mid '90s) pushrod
engine for the Corvette and not pursuing the OHC technology that
they started with the Lotus designed motor.  He said that they
could make similar or more power per pound of *engine* weight
than they could with OHC technology.  Also, it would be smaller
in size (esp. width), which simplifies vehicle assembly.

2.  All this discussion about forced induction:  You are forgetting that
converting a N/A engine to forced requires reducing compression
(read: new pistons) unless the boost is relatively mild.  Similar problems
can exist if you try overboosting an OEM forced induction engine.  Sure,
many of them can tolerate some additional boost, but you have to be
carefull.

3.  Ref: #2, engines with significant boost have low compression, and
tend to be less efficient at part throttle (street/highway).  Thus as a
practical matter, mileage suffers.  I was involved with Callaway Corvettes
in the late '80s.  These engines were stock except modified for strength
via better rods, crank, etc.  Stock cam and heads.  But compression was 8:1
and gas mileage off boost was crappy  (OK, it wasn't so good on boost
either......)

Hans.


On 12/6/07, Fellippe Galletta <fellippe.galletta [at] gmail.com> wrote:
> Just curious...
>
> Is it possible to get a lot of revs from a pushrod motor? Say a redline
> above 7000 rpm....up to 8000 or more?
>
> Not that its necessary, but there is an allure to a very high revving motor
> just for the sound of it. :)
>
> FG