Harley motor in a homebuilt?

wrote:
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

Thanks, Cory, but the point is it's a replica, and I'm trying to make it
look as much like the original as possible. I don't expect to be doing
long cross country trips in it, unless it's a hundred miles at a time. :-)

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

Eric Miller 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.


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



Actually, I'd LOVE for my airplane to go "potato-potato-potato..."!
That's about the only think I like about a Harley. :-)

Yes, the 45 degree configuration is lousy regarding vibration (although
Honda has managed to smooth it out, just add 40 lbs or so of
counterweights). However, it's not as bad as the second engine that was
used in the original plane, the 28 hp Lawrance A-3 -- a two cylinder
opposed with a single crank throw, and no counterbalancing.

The buyer of the plane in 1926 commented on the excessive vibration in a
letter he write in the '80s. I know that in the late '20s someone came
up with a two throw crank conversion for these engines, but I only know
of one of these engines still running. And I'd rather fly behind a new
Harley engine than an 87 year old engine.

Interesting note on the Lawrance A-3 -- it does not have engine mounting
lugs. It has a grooved area around the base of each cylinder where you
*strap* the engine to the airplane. yikes!

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

David

Many years ago, someone told me that motorcycle engines had a lot of
vibration and for that reason were not really reliable for use in a
very light aircraft that their horsepower would pull. Vibrations
caused failures in the structure????

One data point FYI.

Big John


On Fri, 19 Sep 2003 10:06:41 GMT, 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

Indian just went belly up re article in todays paper. Stated in 1902
it said.

Big John


On Fri, 19 Sep 2003 10:06:41 GMT, 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

I live in Nuuk, which is the Inuit name for Godthaab, the largest city
in Greenland.

Happy flying
Jesper Rex
On Tue, 23 Sep 2003 17:05:05 -0500, Big John
wrote:

Jasper

Where in Greenland?

Big John


On Sun, 21 Sep 2003 02:08:15 -0200, Jesper Rex
wrote:

This guy is building a Replica Airplane, that was originally powered
by a V-Twin. I guess that means, that to be a proper Replica he NEEDS
a V-Twin engine to power it, not anything else, no matter how much
better it is.

I don't know anything about building airplanes, but I did a quick
search on the net to see which Airplanes I could find that was Indian
Powered, and it looks like the Original had around 20HP, so I guess
that he would not need the full performance of the Harley Engine.

Just my 5c.

Happy flying from Greenland
Jesper Rex

On 20 Sep 2003 13:36:19 -0700, (Ralph DuBose) wrote:

"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.

On 23 Sep 2003 09:26 AM, David Hill posted the following:

Interesting note on the Lawrance A-3 -- it does not have engine
mounting lugs. It has a grooved area around the base of each
cylinder where you *strap* the engine to the airplane. yikes!

That brings up another point, it might be a really good idea to make a
safety cable from the engine to a lug on the fuselage, in case vibration
gets to be too much for the engine mount...

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

Jasper

How far from 'Sendre Stremfjord'? I was flight leader of a flight of
T-33's and all ejected over 'Son-da-strom' (Sp) Air Base 7 December
1969. All survived and one airplane was later found by a trapper on a
frozen lake where it had landed (crashed) and skidded across the lake
to the shore.

Always wondered if they later ever found the bird with the cargo pod
where I had all my civilian clothes and msc? Had a suit I got in Hong
Kong with English material. One of the best fitting suits I ever had
and material was outstanding.. Of course none of those clothes would
fit me now? Time and fat wait for no man G

Wx was 1000 and one in light snow and GCA radio's quit (
Everything outside cockpit was white. Ground, sides of the Fiords,
etc.

Found you on the map. Your about 150 SM south of 'Sondie'.


Big John


On Tue, 23 Sep 2003 22:32:22 -0200, Jesper Rex
wrote:

I live in Nuuk, which is the Inuit name for Godthaab, the largest city
in Greenland.

Happy flying
Jesper Rex
On Tue, 23 Sep 2003 17:05:05 -0500, Big John
wrote:

Jasper

Where in Greenland?

Big John


On Sun, 21 Sep 2003 02:08:15 -0200, Jesper Rex
wrote:

This guy is building a Replica Airplane, that was originally powered
by a V-Twin. I guess that means, that to be a proper Replica he NEEDS
a V-Twin engine to power it, not anything else, no matter how much
better it is.

I don't know anything about building airplanes, but I did a quick
search on the net to see which Airplanes I could find that was Indian
Powered, and it looks like the Original had around 20HP, so I guess
that he would not need the full performance of the Harley Engine.

Just my 5c.

Happy flying from Greenland
Jesper Rex

On 20 Sep 2003 13:36:19 -0700, (Ralph DuBose) wrote:

"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.

This month's Kit Planes talks about a Nieuport replica with a Yamaha
engine as the powerplant. The guy has the engine locked in second
gear to supply his reduction. I saw a site with it a long time ago
but can't find it now. Apparently it has hours on it in the air and
pulls ok. Personally I have no opinion on the feasability but we are
experimenters.

Canuck Bob wrote:
This month's Kit Planes talks about a Nieuport replica with a Yamaha
engine as the powerplant. The guy has the engine locked in second
gear to supply his reduction. I saw a site with it a long time ago
but can't find it now. Apparently it has hours on it in the air and
pulls ok. Personally I have no opinion on the feasability but we are
experimenters.

When I first started looking at using a V-Twin motorcycle engine, my
inclination was to use a Jap V-Twin rather than a Harley, mainly because
in motorcycles the Jap engines are 1) smoother, 2) more reliable, and 3)
more powerful. However, the big drawback is that the transmission is
integral with the engine.

The plus side of that is you already have a well engineered gear
reduction system in place. The minus side is you have a lot of extra
weight that you really don't need. I've talked to folks that used other
Jap engines; they removed as much of the transmission innards as they
could, leaving only what was necessary. This involved some tricky
welding, and still left a lot of metal in place that wasn't really needed.

My inclination changed recently after I dropped by a local Harley shop
and started asking questions.

Turns out the Harley motor is separate from the transmission.

Turns out you can get a new-in-the-crate Evo engine for about $2900.
Comes with dual sprockets standard on the crank (just waiting for a
chain drive PSRU).

Turns out it's a dry sump engine; requires a separate oil tank. Can you
say "lots and lots of oil, and an oil cooler to boot"? That'll help a
lot in regard to engine cooling.

Turns out you can get it either carburated or with electronic fuel
injection. EFI means I can keep the simple single lever control
(throttle only) of the original plane, but be able to operate
efficiently at varying altitudes.

So, the only hard part is designing and building the PSRU. I've seen
the one at http://www.hog-air.com/. From the pictures it looks like it
ties in to the cylinder heads, while the engine mounts are at the base
of the cylinders. It seems this would put a bending stress on the
cylinder bases that they were not designed for. I hope to get a first
hand look at it next month and ask the designer about it.
--
David Hill
david at hillREMOVETHISfamily.org
Sautee-Nacoochee, GA, USA

So, the only hard part is designing and building the PSRU. I've seen
the one at http://www.hog-air.com/. From the pictures it looks like it
ties in to the cylinder heads, while the engine mounts are at the base
of the cylinders. It seems this would put a bending stress on the
cylinder bases that they were not designed for. I hope to get a first
hand look at it next month and ask the designer about it.

Couldn't find any specs on the engine other than the torque at 3000 RPM,
and the Harley web site, like the hog-air web site, was kind of a pain
to navigate.

Any idea if they have the power curve on line?

thanks

Ed Wischmeyer