Harley motor in a homebuilt?

There was a newer Harley engine spinning a prop on a stand down at Sun'n'fun
this year. Can't remember the guys name. However with the newer Evos and
there twin balanced setup it seemed very promising and ran very smooth. Once
again I emphazise it was a newer Evo twin cam 88 motor.
John

David Hill wrote ...
I'm working on a replica of a 1924 airplane originally powered by an
Indian Chief motorcycle engine. I've spent a year or two trying to find
a modern engine that somewhat resembles the Indian, and the best I have
come up with is a Harley-Davidson.

Why not a current production Indian? Can't say that I know anything
about motorsickles, but I noticed one of the new ones a couple weeks
ago & wondered.

... I can get ~40 hp at ~3400 rpm
(direct drive) or ~60 hp at ~4500 rpm (PSRU setup).

Better check your math (PSRU = more torque @ lower rpm, but the HP
stays the same).

Daniel

"Daniel" wrote in message
om...
Better check your math (PSRU = more torque @ lower rpm, but the HP
stays the same).

Daniel...........

Better check yours. He's talking about engine rpm. ;o)

Rich S.

On 20 Sep 2003 17:48:25 -0700, (Daniel)
wrote:

David Hill wrote ...
I'm working on a replica of a 1924 airplane originally powered by an
Indian Chief motorcycle engine. I've spent a year or two trying to find
a modern engine that somewhat resembles the Indian, and the best I have
come up with is a Harley-Davidson.

Why not a current production Indian? Can't say that I know anything
about motorsickles, but I noticed one of the new ones a couple weeks
ago & wondered.

... I can get ~40 hp at ~3400 rpm
(direct drive) or ~60 hp at ~4500 rpm (PSRU setup).

Better check your math (PSRU = more torque @ lower rpm, but the HP
stays the same).

Daniel
No, David was right. Engine torque output being the same, horsepower
increases proportional to speed. Since torque droops with RPM, the
difference is not truly linear - but running a PSRU ALLOWS the engine
to produce more horsepower with the same prop RPM.If it did not, there
would be no reason for the complexity of a PSRU.

"Eric Miller" wrote in message .net...

Do you really want your airplane to go "potato-potato-potato..." ? :-)

You could pretend it was a P&W R-2800.... ;-

To All: To make the man happy, Indian motorcycle is back in business. He
should look them up, for real authenticity. :-)

clare @ snyder.on .ca wrote ...

No, David was right. ...

He sure was. I misread what he meant. Engine RPM vs prop RPM. The error was mine.

Daniel

Old Sarge wrote:
To All: To make the man happy, Indian motorcycle is back in business. He
should look them up, for real authenticity. :-)


Thanks, Sarge, but you missed the main point. It's a replica, and I'm
looking for something that at least resembles the old Indian Chief. The
New Indian is the first place I looked, they don't resemble the old
Indian any more than the Harley, and they cost a lot more.

David Hill
david at hillREMOVETHISfamily.org

cj wrote:
snip
Hello,

About six months ago Larry Smith posted this link:

http://www.hog-air.com.

It is bigger than what you are talking about, and it doesn't look like
it has flown yet, but the motor is bolted onto an airframe:

http://www.hog-air.com/Motor%20running.WMV

They're talking about selling completed Light Sport Aircraft for
$52,000.

- cj

You know, I saw this website a while back. At the time, I couldn't get
past the first page, and I thought it was some kind of joke. Now I see
they are serious. Doesn't look exactly like what I want, but it will be
worth talking to them.

thanks,
--
David Hill
david at hillREMOVETHISfamily.org
Sautee-Nacoochee, GA, USA

Ken Sandyeggo wrote:
David Hill wrote in message .. .

I'm working on a replica of a 1924 airplane originally powered by an
Indian Chief motorcycle engine. I've spent a year or two trying to find
a modern engine that somewhat resembles the Indian, and the best I have
come up with is a Harley-Davidson.

Looks like with an 80 cid Evolution engine I can get ~40 hp at ~3400 rpm
(direct drive) or ~60 hp at ~4500 rpm (PSRU setup).

Has anyone here tried this? Or know of anyone who has done this? I'm
looking for caveats, tips, and techniques. Based on experience, not
opinion. Oh, sorry, I forgot where I was. grin


Second hand caveat: This topic has been beaten to death, buried,
resurrected and beaten to death several more times on the gyro forum.
As I recall, the problem is heat. Running at the rpm we need to spin a
prop is too much for a motorcycle engine. After initial acceleration,
they basically loaf down the road. The sustained revs will fry them.
This what I recall being posted by people who seemed to know what they
were talking about. Craig Wall had some very spirited and seemingly
logical and convincing posts as to why they won't work. But then
again, someone may prove them wrong and get one to successfully
perform. I don't believe anyone has a good handle on it yet, with
proven reliability over a substantial amount of hours.

Ken J. - SDCAUSA

I seem to recall all the same posts. Which is why I never seriously
considered it, until I got involved with this replica project. The
original plane first flew on 17 hp with the Indian Chief motor, then was
changed to a 28 hp Lawrance A-3 (talk about vibration!). Even if all I
get out the Harley is 40 hp, I'll be doing okay.

thanks,
--
David Hill
david at hillREMOVETHISfamily.org
Sautee-Nacoochee, GA, USA