Looking for a sub-100hp engine with long TBO time.

This is for a hypothetical ultralight design, so just looking for
suggestions here of where to look at... hopefully a 4-stroke, purchase
price doesn't matter much, certification status doesn't matter either.
Long time before overhaul matters A LOT... so, the longer the better.
Is there anything out there in the 80-hp range? How about a motorcycle
engine conversion - how long can those go before needing to be
overhauled?

Thanks!

Check out the Honda four stroke personal watercraft engines. They're
powerful and designed to run at full load for extended lengths of time.
However, you'd have to use a reduction unit to get the RPM down low
enough to drive a prop.

Tony

tffy wrote:
This is for a hypothetical ultralight design, so just looking for
suggestions here of where to look at... hopefully a 4-stroke, purchase
price doesn't matter much, certification status doesn't matter either.
Long time before overhaul matters A LOT... so, the longer the better.
Is there anything out there in the 80-hp range? How about a motorcycle
engine conversion - how long can those go before needing to be
overhauled?

Thanks!

I was wrong about those four stroke personal watercraft engines. The
Honda engine is rated at 137HP and the Yamaha engines are rated at 110
to 160HP. All of these are much bigger than you were looking for.

Tony

tffy wrote:
This is for a hypothetical ultralight design, so just looking for
suggestions here of where to look at... hopefully a 4-stroke, purchase
price doesn't matter much, certification status doesn't matter either.
Long time before overhaul matters A LOT... so, the longer the better.
Is there anything out there in the 80-hp range? How about a motorcycle
engine conversion - how long can those go before needing to be
overhauled?

Thanks!

"Anthony W" wrote in message
news:gQPcf.7191$vC6.670@trnddc05...
Check out the Honda four stroke personal watercraft engines. They're
powerful and designed to run at full load for extended lengths of time.
However, you'd have to use a reduction unit to get the RPM down low
enough to drive a prop.

I think I am correct in saying that others have tried using a boat type
powerplant before, and have found problems, especially with keeping them
cool.

With a closed loop (most engines not on the water) water cooled engine, the
engine sees cooling water at a pretty low temperature. They usually have
unregulated flow, and unlimited water, so the cooling passages don't have to
be very large, or move the water very fast to be effective in keeping the
engine cool. Closed loop systems see water coming in at around 180 degrees,
so the flow has to pass through quickly and soak up as much heat as they
can, but are not able to take on much more heat. (because of it's already
high temperature) The passages have to be larger, and contact more of the
hot parts to remove enough heat to keep the engine cool.
--
Jim in NC

I think the Yamaha engines are the same that are in snowmobiles. The snow
version would be closed loop.
Jerry

"Morgans" wrote in message
...

"Anthony W" wrote in message
news:gQPcf.7191$vC6.670@trnddc05...
Check out the Honda four stroke personal watercraft engines. They're
powerful and designed to run at full load for extended lengths of time.
However, you'd have to use a reduction unit to get the RPM down low
enough to drive a prop.

I think I am correct in saying that others have tried using a boat type
powerplant before, and have found problems, especially with keeping them
cool.

With a closed loop (most engines not on the water) water cooled engine,
the
engine sees cooling water at a pretty low temperature. They usually have
unregulated flow, and unlimited water, so the cooling passages don't have
to
be very large, or move the water very fast to be effective in keeping the
engine cool. Closed loop systems see water coming in at around 180
degrees,
so the flow has to pass through quickly and soak up as much heat as they
can, but are not able to take on much more heat. (because of it's already
high temperature) The passages have to be larger, and contact more of the
hot parts to remove enough heat to keep the engine cool.
--
Jim in NC

Why not just go with a Jabiru 2200?

A TBO of 2000 hours currently applies, with a top end TBO of 1000 hours. A
TBO of 2000 hours currently applies, with a top end TBO of 1000 hours.

Air cooled + no redrive = simple.

Reasonably priced.


"tffy" wrote in message
oups.com...
This is for a hypothetical ultralight design, so just looking for
suggestions here of where to look at... hopefully a 4-stroke, purchase
price doesn't matter much, certification status doesn't matter either.
Long time before overhaul matters A LOT... so, the longer the better.
Is there anything out there in the 80-hp range? How about a motorcycle
engine conversion - how long can those go before needing to be
overhauled?

Thanks!

"Lakeview Bill" wrote in message
. ..
Why not just go with a Jabiru 2200?

A TBO of 2000 hours currently applies, with a top end TBO of 1000 hours. A
TBO of 2000 hours currently applies, with a top end TBO of 1000 hours.

Air cooled + no redrive = simple.

Reasonably priced.


Good suggestion! Should do very well for an ultralight.

Rob

(Ouch, someone mentioned Jabiru... I'm waiting in suspense for the response
of Bret L...)

Thanks for that suggestion, will check it out. Still looking for other
options out there though!

You should check out the Rotax 912. It is 80hp, four stroke, and weighs
about 125 pounds. It has a TBO of 1500 hours.

tom pettit


"tffy" wrote in message
oups.com...
This is for a hypothetical ultralight design, so just looking for
suggestions here of where to look at... hopefully a 4-stroke, purchase
price doesn't matter much, certification status doesn't matter either.
Long time before overhaul matters A LOT... so, the longer the better.
Is there anything out there in the 80-hp range? How about a motorcycle
engine conversion - how long can those go before needing to be
overhauled?

Thanks!

Thanks! There isn't anything 2-cylinder available in this power range
(or perhaps less, all the way down to 60hp), is there? The a/c
performance can afford to be somewhat anemic, while mounting space is
at a premium.