Standards for H.P. corr. factors ??

wrote in message
oups.com...

I get a kick out of the 100 HP VW's, especially.
--
Jim in NC
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Even 80hp should have you rolling on the floor :-)

After waving the magical 80hp flag at a tent-full of round-eyed
admirers the next kerchief out of his sleeve is usually "3.3 gph"
followed by a round of patting himself on the back in routine worth of
a French circus. Are we great or what?

Truth is, if you know engines and want some serious fun, get a bunch
of real engine guys together and show them the Aero-vee assembly
video. I swear to God it's the funniest thing I've seen in years.
Seriously. Most guys assume it's a put-on. When they realize it's
being sold as a 'expert advice' their reactions range from blowing
beer out their nose to simply sitting there in stunned amazement.

-R.S.Hoover

I am much more of a theoretical engine guy than a real engine guy, and IIRC
it took a little effort on your part to set me straight on the thermal
limits of the VW heads; so I have faith that you will help to clear up
whatever misconceptions I may have on this as well.

With that disclaimer...

it seems to me that there is an additional way to look at the 80HP VW issue:
80HP from 130CID at 3450RPM is plausible in standard air; for a time limited
by cooling, etc. However, my limited knowledge of propellers suggests that
either the RPM or the manifold pressure must change quite soon--even with an
engine that could handle the load continuously--and I am not convinced that
it is achievable more than momentarily

Soooo.... the 3.3GPH may be the real key to the puzzle. Given a fixed
pitch prop, there is no way for this all to happen at the most efficient RPM
and MP. Therefore, 3.3GPH means to me that cruise is less than 43HP; since
about 13 horsepower hours per gallon is the best it can get under the
circumstances and with the type of engine and fuel system in use.

And then... dividing 43 by 0.75 it becomes clear that, when the subsequent
round table discussion is included, this is at least a 3-Beer video.

Peter
(Also starting to wonder about that little jewel from down under... )

I get a kick out of the 100 HP VW's, especially.
--
Jim in NC

--------------------------------------------------------------------------
-----------------

Even 80hp should have you rolling on the floor :-)

After waving the magical 80hp flag at a tent-full of round-eyed
admirers the next kerchief out of his sleeve is usually "3.3 gph"
followed by a round of patting himself on the back in routine worth of
a French circus. Are we great or what?

Truth is, if you know engines and want some serious fun, get a bunch
of real engine guys together and show them the Aero-vee assembly
video. I swear to God it's the funniest thing I've seen in years.
Seriously. Most guys assume it's a put-on. When they realize it's
being sold as a 'expert advice' their reactions range from blowing
beer out their nose to simply sitting there in stunned amazement.

-R.S.Hoover

I am much more of a theoretical engine guy than a real engine guy, and
IIRC
it took a little effort on your part to set me straight on the thermal
limits of the VW heads; so I have faith that you will help to clear up
whatever misconceptions I may have on this as well.

With that disclaimer...

it seems to me that there is an additional way to look at the 80HP VW
issue:
80HP from 130CID at 3450RPM is plausible in standard air; for a time
limited
by cooling, etc. However, my limited knowledge of propellers suggests
that
either the RPM or the manifold pressure must change quite soon--even with
an
engine that could handle the load continuously--and I am not convinced
that
it is achievable more than momentarily

Soooo.... the 3.3GPH may be the real key to the puzzle. Given a fixed
pitch prop, there is no way for this all to happen at the most efficient
RPM
and MP. Therefore, 3.3GPH means to me that cruise is less than 43HP;
since
about 13 horsepower hours per gallon is the best it can get under the
circumstances and with the type of engine and fuel system in use.

And then... dividing 43 by 0.75 it becomes clear that, when the
subsequent
round table discussion is included, this is at least a 3-Beer video.

Peter
(Also starting to wonder about that little jewel from down under... )


It seems that I got so wrapped up in my writing that I forgot just how close
that cruising power might be to the practical maximum continuous....

Peter :-(

On Jul 7, 1:39 pm, "Peter Dohm" wrote:

I am much more of a theoretical engine guy than a real engine guy, and IIRC
it took a little effort on your part to set me straight on the thermal
limits of the VW heads; so I have faith that you will help to clear up
whatever misconceptions I may have on this as well.
----------------------------------------------------------------------------------------

Dear Peter,

The magnesium crankcase is referred to as aluminum, old, used parts
are referred to as 'factory new,' bearing shells are installed atop a
splatter of spray-paint... But the humor has more to do with the
overall incompetence of the video rather than the fallacious
statements. The video is larded with hilarious Mechanical Sight-Gags
that can't be described without losing the essence of the humor; you
NEED to see it for yourself.

The Beer Fountain erupted when, upon completing some mundane task, the
assembler puts thumb to forefinger and gives the camera a close-up
'okay' for all the deaf-mutes in the audience. Doing it once was
funny but the second time even Old Stoneface cracked up: 'This guy
makes Dubya look like a Whiz Kid.'

Giiven the nature of the medium -- the ability to re-shoot a take
until they got it right -- it's hard to understand why they would
leave in so many scenes showing them doing things wrong. That caused
a bit of discussion, some arguing that it had to be a put-on... until
someone pointed out that they probably HAD re-shot and edited TO THE
BEST OF THEIR ABILITY. Which makes the video a ****-up of truly
monumental proportions.

Like I said, you've GOT to see it. This thing is a collector's item.

-R.S.Hoover

wrote in message
oups.com...
On Jul 7, 1:39 pm, "Peter Dohm" wrote:

I am much more of a theoretical engine guy than a real engine guy, and
IIRC
it took a little effort on your part to set me straight on the thermal
limits of the VW heads; so I have faith that you will help to clear up
whatever misconceptions I may have on this as well.

--------------------------------------------------------------------------
--------------

Dear Peter,

The magnesium crankcase is referred to as aluminum, old, used parts
are referred to as 'factory new,' bearing shells are installed atop a
splatter of spray-paint... But the humor has more to do with the
overall incompetence of the video rather than the fallacious
statements. The video is larded with hilarious Mechanical Sight-Gags
that can't be described without losing the essence of the humor; you
NEED to see it for yourself.

The Beer Fountain erupted when, upon completing some mundane task, the
assembler puts thumb to forefinger and gives the camera a close-up
'okay' for all the deaf-mutes in the audience. Doing it once was
funny but the second time even Old Stoneface cracked up: 'This guy
makes Dubya look like a Whiz Kid.'

Giiven the nature of the medium -- the ability to re-shoot a take
until they got it right -- it's hard to understand why they would
leave in so many scenes showing them doing things wrong. That caused
a bit of discussion, some arguing that it had to be a put-on... until
someone pointed out that they probably HAD re-shot and edited TO THE
BEST OF THEIR ABILITY. Which makes the video a ****-up of truly
monumental proportions.

Like I said, you've GOT to see it. This thing is a collector's item.

-R.S.Hoover

The search for a copy is now under way!

Thanks,
Peter

"Peter Dohm" wrote

2) The automotive engine stress tests could very well be exactly what
the
name implies--Stress Tests. In other words, they may well be very
carefully
designed tests to predict certian common warranty problems on new engine
models--as used in automobiles where they commonly operate between idle
and
20% power, with occasional bursts of full power and occasional demands for
maximum power from cold engines.

I remember it more as a worst case abuse test. LOTS of WOT running, some of
it for longer periods of time than certifications tests.

Based on that possibility, it would be
very usefull to know the engine coolant outlet *and* inlet temperatures
and
flow rate as well as the oil outlet *and* inlet temperatures and flow rate
during the sustained high power run. (Remember that they have chillers on
line which probably have far more capability than the engines under test.)
There are a few other things I would like to know, specifically for any
engine which I might consider for conversion, such as any additional
steady
speeds which might have been tested; but those temperatures and flow rates
would tell whether the engine showed any promise when using any plausible
cooling system in an aircraft.

Good point about flow rates and temperature.

From the guys that have used Ford and Chevy V-6's, they have not had a
problem with cooling if the system is well designed to create a good
positive air pressure. Shoot, instead of real radiators, most use two GM
air conditioner condenser radiators. It seems like cooling must not be too
hard, with those two little radiators.

The only problem stated is that they can not sit for too long, without
overheating.

I always wondered why they don't put little fans on the radiators, as is
standard for auto applications. I know, a little more weight, but if it got
me though long taxi situations at fly-ins, and big airports, that would be
weight I would be willing to carry.
--
Jim in NC

"Morgans" wrote in message
...

"Peter Dohm" wrote

2) The automotive engine stress tests could very well be exactly what
the
name implies--Stress Tests. In other words, they may well be very
carefully
designed tests to predict certian common warranty problems on new engine
models--as used in automobiles where they commonly operate between idle
and
20% power, with occasional bursts of full power and occasional demands
for
maximum power from cold engines.

I remember it more as a worst case abuse test. LOTS of WOT running, some
of
it for longer periods of time than certifications tests.

The test does include long periods of WOT, in addition to a lot more types
of extremely severe service. My point about the idle to 20% power is that
most of the engines sold will be used in automobiles with mostly very
lightly loaded operation, interspersed with bursts of acceleration onto
highways and occasional panic acceleration with cold engines. As I
understand it, the real purpose of the tests is to accelerate the possible
failures of a few critical parts, such as vibration dampers and head
gaskets, in an effort to predict and control the long term costs associated
with warranties--and especially extended warranties and service contracts
which can frequently by 7 years and 100,000 miles.

Based on that possibility, it would be
very usefull to know the engine coolant outlet *and* inlet temperatures
and
flow rate as well as the oil outlet *and* inlet temperatures and flow
rate
during the sustained high power run. (Remember that they have chillers
on
line which probably have far more capability than the engines under
test.)
There are a few other things I would like to know, specifically for any
engine which I might consider for conversion, such as any additional
steady
speeds which might have been tested; but those temperatures and flow
rates
would tell whether the engine showed any promise when using any
plausible
cooling system in an aircraft.

Good point about flow rates and temperature.

From the guys that have used Ford and Chevy V-6's, they have not had a
problem with cooling if the system is well designed to create a good
positive air pressure. Shoot, instead of real radiators, most use two GM
air conditioner condenser radiators. It seems like cooling must not be
too
hard, with those two little radiators.

The only problem stated is that they can not sit for too long, without
overheating.

It's good to hear that the cooling works reasonably well at normal power
levels--at least for the V6 engines. There are basically two cooling
problems to overcome at idle: First, there is the usual problem of
downdraft cooling in which the air must be pushed downward even though
convection wants to move it the other way--and a lot of air cooled engines
have the same problem when the installation is entirely designed around high
speed and low drag and the cooling inlets are simply too small to get the
job done at idle. The second problem is peculiar to liquid cooled engines
in which most of the coolant in the radiators is positioned lower than most
of the coolant in the engine--the water pump needs to turn fast enough to
move the coolant in a direction opposite from its natural convection. The
result is that a lot of V6 and V8 engine installations with offest reduction
drives (usually belt or chain) probably suffer from a "double wammy" in
terms of cooling difficulty at idle. OTOH, some of the inverted
installations, such as Steve Wittman's conversion for the Tailwind, which
had updraft cooling and the radiator mounted above the inverted crankcase,
should be immune from those problems--although I neglected to ask Steve
Wittman that question and have not had an opportunity to ask anyone else
with real world experience.
(He was in attedance and had the V8 Tailwind on display at SnF a number of
years ago.)

I always wondered why they don't put little fans on the radiators, as is
standard for auto applications. I know, a little more weight, but if it
got
me though long taxi situations at fly-ins, and big airports, that would be
weight I would be willing to carry.

I don't know the real reason, but fans would definitely restrict the airflow
at speed. That could be a greater penalty than the modest weight.

Peter