Harley motor in a homebuilt?

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

--
David Hill
Sautee-Nacoochee, GA, USA

Can't remember who, but I recall seeing a Harley re-drive article in
"Experimenter" I think. .... a few years ago.

"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.

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

--
David Hill
Sautee-Nacoochee, GA, USA

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

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

Based on experience and opinion; Do you know why Harley riders wave to
each other as they pass on the hi-way? Because they never know when
they're going to have to borrow parts from each other so they want to
stay on the good side of every Harley rider they meet. budah bump.

I would say trusting your life to a Harley engine is worse judgement
than trusting your life to a Rotax engine.

Bill
You're nothing until you've blasted a can of Delmonte peas with a
Walther P-38... or something like that.

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

Based on experience and opinion; Do you know why Harley riders wave to
each other as they pass on the hi-way? Because they never know when
they're going to have to borrow parts from each other so they want to
stay on the good side of every Harley rider they meet. budah bump.

Difference between a biker and a Viking? Vikings wear helmets. budum
ching. Ever read, "Zen and the Art of Motorcycle Maintenance?" Still
and all, it could be worse. He could be wanting to install a Triumph
engine, or worse, a *shudder* Lucas electrical system. (Why doesn't
Triumph built televisions? Because they haven't figured out a way to
make them leak oil.)

"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.

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

And on a more serious note, isn't the 45 degree configuration a lousy design
for vibration (or an excellent one, depending on how you look at it ) ?

Eric

On 19 Sep 2003 06:09 PM, Corrie posted the following:

and all, it could be worse. He could be wanting to install a Triumph
engine, or worse, a *shudder* Lucas electrical system. (Why doesn't
Triumph built televisions? Because they haven't figured out a way to
make them leak oil.)

As opposed to a Harley???

----------------------------------------------------
Del Rawlins-
Remove _kills_spammers_ to reply via email.
Unofficial Bearhawk FAQ website:
http://www.rawlinsbrothers.org/bhfaq/

Unless you've already got one, don't mind the craft shaking
itself apart from the inherent imbalance, and can live with the cylinders
frying themselves, think something other than a harley engine. Air cooled
engines work poorly in automobiles, less poorly in motorcycles, and
moderately poorly in airplanes. The inherent problem is that making power
makes *lots* of heat, and in order to remove it with an air-cooled engine
you need a large temperature gradient. This requires CHTs on the order of
400 degrees, extra-special valve construction and materials, cylinder
barrel choke, higher octane requirements, etc, etc. If one's going to go
with something that isn't certified, at least use the best technology
available and use liquid cooling. Cooler, more efficient, roughly the
same weight, less cooling drag, etc, etc. I'm partial to the EA-81 Subaru
engine, but of course I use the same one in my daily driver car...

-Cory

Ken Sandyeggo wrote:
: 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

--
************************************************** ***********************
* The prime directive of Linux: *
* - learn what you don't know, *
* - teach what you do. *
* (Just my 20 USm$) *
************************************************** ***********************

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

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

And on a more serious note, isn't the 45 degree configuration a lousy design
for vibration (or an excellent one, depending on how you look at it ) ?

Eric

In the world of high performance hovercraft, motorcycle engines
have been looked at for years. The only situations where they have
been made to work is where they are installed complete with gearbox
and rigged with a complex chain to belt PSRU. Also, they need to be in
an application where full power is rarely needed. After starring at
these harsh realities, most people choose between 2 stroke power or
Kohler reliability. Or for larger craft, a junkyard 4 cylinder car
engine.