Clup prop

[Corky Scott]

I'm looking for a club prop I can use to break in/test an engine. I
could use a regular prop I suppose, but the engine will be on a test
stand and I'd rather have something with a reduced diameter for
safety.

The engine will be producing around 180 to 190 hp and I'd like to be
able to run it up to full power/rpm for extended periods. Maximum
prop rpm will be 2400. The prop hub has a standard bolt pattern.

Any ideas? Suggestions?

Thanks, Corky Scott

[Rich S.]

"Corky Scott" > wrote in message
...
> I'm looking for a club prop I can use to break in/test an engine. I
> could use a regular prop I suppose, but the engine will be on a test
> stand and I'd rather have something with a reduced diameter for
> safety.
>
> The engine will be producing around 180 to 190 hp and I'd like to be
> able to run it up to full power/rpm for extended periods. Maximum
> prop rpm will be 2400. The prop hub has a standard bolt pattern.
>
> Any ideas? Suggestions?

Hook it to a generator and sell the electricity to the local power company?

Rich "Waste not, want not" S. :)

[Russell Kent]

Corky Scott wrote:

> I'm looking for a club prop I can use to break in/test an engine. I
> could use a regular prop I suppose, but the engine will be on a test
> stand and I'd rather have something with a reduced diameter for
> safety.
> The engine will be producing around 180 to 190 hp and I'd like to be
> able to run it up to full power/rpm for extended periods. Maximum
> prop rpm will be 2400. The prop hub has a standard bolt pattern.
>
> Any ideas? Suggestions?

"Rich S." replied:

> Hook it to a generator and sell the electricity to the local power company?

Not a half bad idea, until you do the math. At 180 HP at the prop you're
talking 134 kilowatts of power. That's probably _only_ 120 kilowatts if the
generator is 90% efficient. (Actually, I hope it is better than that, because
the leftover watts go into heating the generator!) It seems to me that a
generator capable of handling that size power conversion would be expensive to
rent...

Russell Kent

[Rich S.]

"Russell Kent" > wrote in message
...
>
> Not a half bad idea, until you do the math. At 180 HP at the prop you're
> talking 134 kilowatts of power. That's probably _only_ 120 kilowatts if
the
> generator is 90% efficient. (Actually, I hope it is better than that,
because
> the leftover watts go into heating the generator!) It seems to me that a
> generator capable of handling that size power conversion would be
expensive to
> rent...

Split the profit with the generator owner. If you cook the books right,
there won't be any money left over for him - you know, like Hollywood
studios do when they make a percentage deal with a star.

Rich "It's all in the numbers" S.

[Bob Chilcoat]

The electric fan you'll need to run to keep the engine cool will eat up a
lot of your profit.

--
Bob (Chief Pilot, White Knuckle Airways)


"Rich S." > wrote in message
...
> "Russell Kent" > wrote in message
> ...
> >
> > Not a half bad idea, until you do the math. At 180 HP at the prop
you're
> > talking 134 kilowatts of power. That's probably _only_ 120 kilowatts if
> the
> > generator is 90% efficient. (Actually, I hope it is better than that,
> because
> > the leftover watts go into heating the generator!) It seems to me that
a
> > generator capable of handling that size power conversion would be
> expensive to
> > rent...
>
> Split the profit with the generator owner. If you cook the books right,
> there won't be any money left over for him - you know, like Hollywood
> studios do when they make a percentage deal with a star.
>
> Rich "It's all in the numbers" S.
>
>

[Big John]

Bob

Talking about fans reminded me of this bit of humor.


BLONDE PILOT

Now this is right up there as far as blond jokes go.

A blonde pilot decided she wanted to learn how to fly a helicopter.
She went to the airport, but the only one available was a
solo-helicopter. The instructor figured he could let her go up alone
since she was already a pilot for small planes and he could instruct
her via radio.

So up the blonde went. She reached 1,000 feet and everything was going
smoothly. She reached 2,000 feet. The blonde and the instructor kept
talking via radio. Everything was going smoothly.

At 3,000 feet the helicopter suddenly came down! It skimmed the top of
some trees and crash landed in the woods. The instructor jumped into
his jeep and rushed out to see if the blonde was okay. As he reached
the edge of the woods, the blonde was walking out. "What happened?"
the instructor asked. "All was going so well until you reached 3,000
feet. What happened then?"

"Well," began the blonde, "I got cold. So I turned off the ceiling
fan."

[Daniel]

(Corky Scott) wrote in message >...
> I'm looking for a club prop I can use to break in/test an engine. I
> could use a regular prop I suppose, but the engine will be on a test
> stand and I'd rather have something with a reduced diameter for
> safety.
>
> The engine will be producing around 180 to 190 hp and I'd like to be
> able to run it up to full power/rpm for extended periods. Maximum
> prop rpm will be 2400. The prop hub has a standard bolt pattern.
>
> Any ideas? Suggestions?
>
> Thanks, Corky Scott

Lots of OT responses, which is OK, but I'd like to hear an on topic
answer to how one sizes an appropriate club for any given engine.
Anybody have an answer?

Daniel

[Big John]

Daniel

On thread.

The problem can be broken down into two sub problems.

1. The 'club' is a flywheel and used to absorb the firing impulses
like a standard flight prop. Size can be back engineered as to weight
to give the proper flywheel. Home made one should be out of proper
wood, have proper hole pattern and front and back flanges to prevent
crushing wood and of course balanced. Should be re torqued and
inspected after each run. Should be run short runs until it has been
qualified for long runs.

2. Engine is air cooled (unless it is Corky's water cooled auto
conversion) and needs some cooling air which can be from the club or
an external fan. Since a 'club' is normally short you can put a high
pitch on it to blow air for cooling (you are not looking for flight
efficiency). You do have to balance the pitch load against the power
output at max throttle (and rpm).

If a water cooled engine, you can use a radiator and cool via the
'club' air or other means. Even make a water heat exchanger (put
radiator in a tub of water that you can let fresh water run in from
your facet to keep a cool bath. to bleed off the heat).

Hope these ramblings give Corky some ideas on what he can do (cheap
and in house).

One other thing he might do is check shops that rebuild engines and
see what they use and where they get any device (club) and if he could
rent or borrow for his tests.

Also contact EAA to see what they have. Also go on Internet to other
engine conversion groups and ask what they do to qualify their
engine(s). Don't invent the wheel if you don't have to.

Took a break and called around Houston with no success. One said to
look in Trade-a-Plane which might be a good idea.

Looked further on Internet and found data that says the club should
be calibrated to let engine put out max horse power at WOT. They said
that both Lyc and Con had bulletins about testing (they wouldn't apply
directly to Corky's engine but might give him some ideas of what
should be done and how?

Also if a auto speed shop with a dynamiter (sp) is available, use it
to document rpm, torque, etc. before reliability runs on test stand in
his shop.

Have at it Corky and keep us informed how things turn out.


Big John


On 14 Nov 2003 05:28:53 -0800, (Daniel)
wrote:

(Corky Scott) wrote in message >...
>> I'm looking for a club prop I can use to break in/test an engine. I
>> could use a regular prop I suppose, but the engine will be on a test
>> stand and I'd rather have something with a reduced diameter for
>> safety.
>>
>> The engine will be producing around 180 to 190 hp and I'd like to be
>> able to run it up to full power/rpm for extended periods. Maximum
>> prop rpm will be 2400. The prop hub has a standard bolt pattern.
>>
>> Any ideas? Suggestions?
>>
>> Thanks, Corky Scott
>
>Lots of OT responses, which is OK, but I'd like to hear an on topic
>answer to how one sizes an appropriate club for any given engine.
>Anybody have an answer?
>
>Daniel

[John Roncallo]

Daniel wrote:

> (Corky Scott) wrote in message >...
>
>>I'm looking for a club prop I can use to break in/test an engine. I
>>could use a regular prop I suppose, but the engine will be on a test
>>stand and I'd rather have something with a reduced diameter for
>>safety.
>>
>>The engine will be producing around 180 to 190 hp and I'd like to be
>>able to run it up to full power/rpm for extended periods. Maximum
>>prop rpm will be 2400. The prop hub has a standard bolt pattern.
>>
>>Any ideas? Suggestions?
>>
>>Thanks, Corky Scott
>
>
> Lots of OT responses, which is OK, but I'd like to hear an on topic
> answer to how one sizes an appropriate club for any given engine.
> Anybody have an answer?
>
> Daniel

I would say trial and error would be the easyest way. Start big and
shave down until you get your 2400 RPM at WOT.

John Roncallo