"Bertie the Bunyip" wrote in message
.. .
"Peter Dohm" wrote in
:

"Bertie the Bunyip" wrote in message
.. .
wrote in
news:5929b616-fa26-4bd1-acde-baf81ddc4b29
@s12g2000prg.googlegroups.com:

Hey, I found this on the same page, about a VW miracle engine.

http://www.youtube.com/watch?v=O4zSld30cmw&feature=related

It claims 211 HP out of a modified VW engine.

Very interesting.

If you buy that one, I have a bridge to sell you. It's right next
to th
e
ocean-front property in Arizona.
--
Jim in NC

It is possible to build VW engines that have much higher HP than
that. Some racing engines top 400, I think.


I wouldn't be surpised if you couldn't get more than that, even.
Blown F1 engines based on engines almsot as simple ( the BMW M10, for
instane) were knocking on 1,000 HP thirty years ago.
Wouldnt like to fly behind one though!

Even a bit over a hundred has to be the limit for a reliable VW
engine, and
even then it's not going to be very torquey.



Bertie


This is the wrong NG to really attract a firestorm on this subject;
however I am really inclined to agree with you about the practical
limit for a VW. However, there is a major caveat--according to sources
that I trust, ram air will not provide enough cooling during climb for
more than about half of that. Therefore, in addition to the obvious
of a PSRU, a high horsepower VW would also require a relatively high
pressure cooling fan and the attendant machinery to regulate it. And
that is still no guarantee of a successfull outcome.

There is also a second point about automotive racing engines that is
frequently overlooked: I don't have any source of real numbers, but
an occasional few minutes of "standing by the fence and watching the
cars pass by" has convinced me that that road racing averages out to
around 30 to 35% of maximum horsepower--although some oval track
racing on super speedways should be a much higher percentage of power.
In any case, the design life expectancy (and reliability) of an
engine for endurance road racing is obviously far less than I would
consider acceptable for flying--with the obvious exception of air
racing.

When you add it all up, a good conservative automotive conversion can
save money at the expense of performance; but a purpose designed
aircraft engine is still the least expensive source of reliable
lightweight power. I am not happy about that, and I keep looking, but
around 70 to 75% of the power that an engine developed for its
original (factory warranteed) application still looks like a practical
limit.

Yeah, an automotive conversion really doesn;t appeal to me for a lot of
reasons. Some VW designs are realyl fun though! And breaths there a
pilot with a soul so dead as to not turn and look at a nice model A
poswered Piet?

Bertie

Very true!

Peter