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Old January 4th 07, 10:58 PM posted to rec.aviation.homebuilt
Dale Alexander
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Posts: 30
Default Ok, what about the BD5

Too many years ago to annouce publically, a friend of mine inquired with me
about sawing the gearbox off a Suzuki 750 Water-buffalo. For those of you
who are history impaired regarding two-stroke motorcycles, that engine came
from the GT750 and was a three cylinder two-stroke...or a two cylinder three
stroke...I don't remember

Anyway, with mild port work and a little boost in compression, the 750 would
probably put out 80 horsepower all day long, and Suzuki two strokes of that
time were known for being as reliable as a fire hydrant. The engine would
have weighed maybe 70-80 lbs, but required a water cooling system. And would
have been thirsty...

My friend had 900 hours in motor gliders at the time, I had maybe 20 in GA.
In retrospect, I'm glad the subject went away after a brief period of time.

Dale Alexander

"Whome?" wrote in message
...
On 1/4/2007 3:21:53 PM, "Morgans" wrote:

"BobR" wrote

Probably lots of different reasons why it has not achieved the flying
success it should have but you hit on the biggest and probably most
important, no suitable engine. Yeah, I know that there are now many
good engines that could power it well but its time was then and this is
now. It was ahead of its time then and the needed engine wasn't
available.


I don't think that is quite true. There may be better engines now, but
that
is only part of the problem with the piston engine in the BD-5.

The link escapes me now, but there were tremendous problems with torsional
harmonics, tearing apart everything, all the way along the drive train.

Beef up the driveshaft, and the clutch tore apart. Fix the clutch, and
the
engine mounts cracked, beef them up, and something else broke. So on, and
so on.

Anyone happen to have the links handy that addressed all of these issues?
It was a very interesting read, although a lot of material. I think they
would answer, with great detail, why the 5 never caught on. They self
destructed.

Van's RV-4, RV-6, RV-7, RV-8 and RV-9 aircraft. Those
aircraft were slightly bigger, appealed to more pilots, were easier to
build, used proven available engines, offered performance galore and
were far easier for the average pilot to fly.


Although I have never flown one, the experienced pilots that did said
things
like; it would eat most people alive, that it scared them, and so on.



Are you thinking about this one?
http://www.prime-mover.org/Engines/T.../contact1.html
I ran across it while doing a little research prior to this post.

I think all piston engine designs suffer too much from torsional vibration
problems. But most are just not serious enough to be destructive.

--
Whome?