In a message dated 6/18/00 12:34:48 PM Central Daylight Time, spike66@ibm.net
writes:
> > GBurch1@aol.com wrote: For years, people "in the know" have
> > assumed that overhead cam engines are inherently superior. However, when
> > Mercedes decided to get back into the racing engine business, they
> surprised
> > the world by making their Indy-winning machines "old-fashioned" pushrod
> V8s!
>
> WOW coooool! Have you a URL? I wouldnt have imagined such a thing.
> How do they get the revs with all that reciprocating mass of a pushrod,
> a rocker arm etc? spike
This was all I could find on a quick search, just confirming my memory of the
time and people involved:
* * *
http://www.mclaren.co.uk/mclaren/2000/Mp4-15/mercedes/mercedesvictories.html
1994 Mercedes-Benz purpose-built pushrod engine wins the Indianapolis 500 in
the Penske of pole-setter Al Unser Jr. The new Mercedes C-class wins the DTM
title with Ludwig and the AMG team, Mercedes winning 11 out of 24 races. On
28th October 1994, Mercedes- Benz and McLaren announce their new Formula One
partnership, starting with the 1995 FIA Formula One World Championship.
http://members.aol.com/bjenni7107/980514.htm
Roger Penske's cars won the "Indianapolis 500" ten of the 25 years they
started the race. In what may well have been Penske's final "Indianapolis
500" appearance also, he probably scored his greatest success. The 209 cid
pushrod turbo V8 engine, built by Ilmor Engineering, was conceived by Penske
in November 1993, and the secret project was begun after funding by Mercedes
Benz was secured. Penske had reasoned, after Fittipaldi won the 1993 "500,"
for his team, that the elimination of the wide aprons, inside the turns, at
the Indianapolis Motor Speedway, favored this package. He found a loophole in
the USAC rules, that allowed the production based Buick V6 turbo pushrod
engine to compete, and had his new engine built around those specifications.
* * *
I honestly don't know whether these new pushrod engines rev lower than their
ohc competition, but I'd imagine that one of the things that's made them
winners again is new materials tech that allows a lower-mass pushrod. The
benefits of getting rid of a long timing belt or chain, with all the lash
problems and tension-maintenance issues they give rise to, may offset the
reciprocating mass cost of the pushrods.
[I'm showing my old motor-head background here . . . hand me that wrench,
willya?]
Greg Burch <GBurch1@aol.com>----<gburch@lockeliddell.com>
Attorney ::: Vice President, Extropy Institute ::: Wilderness Guide
http://users.aol.com/gburch1 -or- http://members.aol.com/gburch1
ICQ # 61112550
"We never stop investigating. We are never satisfied that we know
enough to get by. Every question we answer leads on to another
question. This has become the greatest survival trick of our species."
-- Desmond Morris
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