> > > > > > > > Hello every one You can try again and I hope
with better
>> >> > > > luck.Some hi tech glitch in cyber space...??
>> >> > > > Let me know.please. Cheers John.
>> >> >
>> >> > John,
>> >> >
>> >> > I like the 3 piece housing very neat.
>> >> >
>> >> > Do you know what RPM the BMW coupling is rated for?
>> >> >
>> >> > Can you advise of the total all-up weight.
>> >> >
>> >> > In your original assessment did you find splash oiling
>>insufficient?
>> >> > Thanks
>> >> > George
>
>> >> Hello George! According to BMW (9 to 10000rpm) although
I did not
>> >> see the specs on it! The weight of the PSRU
>> >> with the starter is 49 lbs.The flywheel with the coupling is 19 lbs.
>> >> While I was running tests;in the first 45 hrs I
>> >> just ran on slpash,and the temp.never went over 205
degrees! Then ,with
>> >> a nice spinner on the prop the temp. went up to
>> >> 230 degrees. However with the prop pusher mode,the temp stayed at
>> >> 205-degrees. I used 20w50 oil! With the oil from the
>> >> engine directly from the cooler temp. stays around 190 degrees!
>> >>
>> >
>> >19 pounds is WAY too much weight for a rotary engine flywheel John.
>> >
>> >Paul Lamar
>
>
>> I disagree, I had three torsional dampers brake on my Ross gearbox,
>> one that went through the prop and the prop drove a piece through the
>> wing so I installed a 18 lb flywheel and it eliminated the problem
>> and as a side effect there was a very noticeable gain in power as the
>> flywheel absorbs power pulses and gives that power back during the
>> lull so I think it is worth its extra weight.
>> Atkins had the same problem and installed to a flywheel and
>> reported the same results.
>> I also tried my cog belt without a a flywheel and didn't like the
>> vibrations at certain rpm's so I installed a 16 lb flywheel and again
>> there was a noticeable performance gain that was worth the extra
>> weight.
>> I have also noticed this in the off road cars that I have been
>> around, a lot of people install light flywheels but you have a lot
>> more torque with a heavy flywheel.
>>
>> Ken
>There is no doubt that a heavy flywheel smoothes out the torque pulses.
>It is the bigger hammer approach. On the other hand many airplanes are
>flying successfully with the 3 or 4 pound flex plate alone. Tracy
>Crook's damper plate works much better than the old BMW clutch disk
>used by Ross. In your case you have a 5 bladed Warp Drive prop
that probably
>has a lot more rotational inertia than the average bear.
>
>BTW I love those pictures you sent Ken. You lucky dog.
>
>Paul Lamar
The five blade warp drive only weighs in at 18 lbs and I am sure a
damper will work but if a heavy flywheel gives a better climb rate
than the extra weight is paying for it self.
With the heavier flywheel I noticed that it lifted up on the step in
the water better and better climb performance and like I said Atkins
reported the same gain on his RV.
Also Skip Gorman reported better performance on rotary boat engines
and said that there is no way he would run without a flywheel.
Ken
I am surprised a heavy flywheel gives a better climb rate. In theory
there is no HP advantage. Less torsional vibration I'll buy. The
rotary already has
a lot of rotational inertia what with the two nine pound cast iron
rotors and balance weights. Dave Atkins has never flown one of Tracy's
gear boxes to compare. BTW Flywheel windage losses can make a difference
at 6000 to 9000 RPM. The stock flex plate has a few fins on it that
should be removed.
Speaking of heavy flywheels take a look at this EngineAir V8. It was the only
way they could get the gear box to live with out a torsional
vibration damper.
Paul Lamar
A flywheel will absorb power spikes and then give them back in slack times.
In the VW sand world I run a flywheel, a full circle counter weight
crank and a 11 lb front pulley all to get more weight to absorb the
pulses and with that it climbs the dunes better and turns better
times in the 1/4 mile.
In the snowmobile world they make heavier flywheels and they also
climb the hills better and pull harder on the flats.
If you simply put a rubber damper in there the power pulses are
absorbed but little is given back, I do like the rubber damper idea
but I think it needs a flywheel also.
The cog belt is a very good damper but I found that a 16 lb
flywheel with it worked out the best and I think about 16 lb with a
rubber damper on a planetary would be about right.
Ken
Well Mazda reduced the weight of the RX8 flywheel to improve the
engine acceleration. The lighter weight rotors also helped. What
a heavy flywheel does in theory is store energy in the form of
rotating inertia.
If you rev a drag racing engine to 5000 to 9000 and step off the
clutch the energy stored in the flywheel will be transferred to the
wheels in the form of instant HP. If you just drive away you don't
get max torque until the engine can rev to the torque peak.
In the case of the RX8 most people don't rev the engine to 6000 RPM and
step off the clutch. In that case a lighter flywheel allows the engine
and car to accelerate faster. Particularly while in the lower gears when
the RPM climbs rapidly. (I spent 30 years in the car performance test
equipment business :))
Paul Lamar
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