The Subaru RV-7 first flew about a month ago out of Cable (NE L.A
Basin). He is sponsored by Subaru!! He was at Osh this year.
Although
it is a 160 h.p n/a engine he seems to be making only about
130/140hp
(and he is using the MT c/s prop). He had problems with vapor lock
that
he has solved and has some cooling problems. When those are solved
he
plans to install the supercharger he has and 'expects' about 260hp.
(I
wouldn't fly behind a Subaru that was really making 260 hp.)
But, his was a nice FF installation. He is flying and I'm not. :-)
David Leonard
I was surprised to see 5 or 6 Eggenfellner Subes at Osh., all on RV6s.
They
were all at the Eggenfelner display, not the flight line. 2 of them had
the
look of installations that either had some ground run time or had flown.
They are still claiming 165 HP but all other Sube 2.2 & 2.5 users seem
to be
getting 125 - 140. Bob (can't remember last name) who won last year's
Sun
100 race at 207 MPH in his turbocharged Sube powered RV-4 was the only
one
I know who made comparable power to my NA 13B. He blew engine #4 (threw
a
rod) about 6 months ago and Tom Wyatt (Turbo Tom) who prepared the
engines
told him he thought it was time to try something else.
Tracy Crook
tcrook@rotaryaviation.com
www.rotaryaviation.com
Lets see 2.5 liters X 60 cubic inches per liter .... 150 cubic inches.
One HP per cubic inch. Good luck for use as a heavy duty piston engine.
What you have there is a hand grenade.
Most people with Soobs are under gearing.
IMHO They are reluctant to run them at 6500 RPM for take off and climb as
they
sound like they are ready to explode. And they are. So what happens is
they
use a 1.7 psru ratio. The prop is still limited to 2700 RPM, consequently
the
engine is only turning up 4500 RPM, while the rated claimed HP is
generated at 6500 RPM.
Then they wonder why the engine is not generating the claimed for HP.
I explained this to some guy on the OSH line with a Ford V6 complaining
about
lack of power with a 1.7 psru. I suggested a higher ratio and he got this
pained expression on his face. He was thinking what his hand grenade
sounded
like running at full power (full prop load) at 4000 RPM. If you don't
believe
me step into a dyno room while a piston race engine is making steady full
power.
You better wear a bullet proof vest. The first time I did it I was
stunned.
Let me out of here NOW!!!!!
When a car accelerates, even in a 1/4 mile race, the engine only reaches
full
power for a fraction of a second.
It is quite remarkable that an automotive piston engine will run at those
RPMs and it is
tribute to over 100 years of detail development and engineering. At full
power
an exhaust valve is running cherry red and slamming open and slamming shut
over 50 times per second!!!!!!.
BTW We now have some idiot at NASA with no engine or AC design experience
and
no pilots license spending several million dollars of our money on a paper
study
trying to make a Chevy V8 work yet again. In the last five years I can
name five
Chevy V8 AC conversions that have failed including one that 50 million
dollars was invested in.
Paul Lamar
Thomas y Reina Jakits wrote:
I understand "Turbo Tom"īs #4 engine was run at extremly high boost
pressures too! Even the factory Subaro Turboīs donīt make that kind of
power - of course you have a hand grenade!
Thomas J.
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