Re: Engine design

["Paul Misencik" <paul@domain.elided>]

<<2) A bad OHC design is always worse than a decent OHV design.

But isn't this kind of an "apples to oranges" comparison?  A bad design
versus a decent one?  When I posed the original question, I wasn't really
concerned about whether a Corvette was better than a Mustang or anything
like that.  I was more wondering about why choose to develop a completely
new engine for a car - any car - and use a pushrod design.  ESPECIALLY in a
car like the Corvette, which is ostensibly the US's marquis modern
sportscar.

If we assume that GM and Ford and Mercedes-Benz and Porsche and VW and other
major automakers have relatively good, forward-thinking engineering
departments comprised of intelligent, gifted engineers, why is it pretty
much only GM and Ford that still build pushrod engines?  Did Mercedes-Benz
develop an all-new pushrod design for the new E-Class?  At a different price
level, does VW sink a billion dollars into a new pushrod four for the Golf?
Or GM for the Saturn Ion?  If a pushrod engine packages better, that's a big
advantage!  Potentially lower hoodline means better visibility and better
aerodynamics, so why doesn't any "serious" European automaker use them?
Even occasionally?  If no one cares what's under the hood, then in theory
the engineers should be able to design the best, most cost-effective and
most reliable powerplant for any given application, right?  And if pushrod
engines have some advantages in packaging and possibly displacement-for
size, why are pushrod engines found pretty much only in US-built trucks and
Corvettes?

My guess is that the people who buy Corvettes and trucks pretty much demand
it.  That 4.6L OHC Ford engine might be a piece of junk, I don't know, but I
do know that when it came out, the Mustang purists went bananas.  Just as
the Corvette faithful were leery of the ZR-1.  Just as Porsche purists went
bananas when they switched the engines over the watercooling.  Ha!
WATERCOOLING for crying out loud!  There cannot be any argument that an air
cooled engine is a better way to go in a premier sportscar, but marketing
reasons made Porsche hang onto it far longer than they probably should have,
and I think pushrod powerplants are around for the same reason.

BTW - I love my OHC Alfa.  (TAC:  token Alfa content)

Paul Misencik
P. Roman Media
Huntersville, NC  28078
email: paul@domain.elided
www.paoloroman.com
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