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George,
Hoping that they produce something that not only works,
but is within financial reach. The history to date of FWF packages (including
the last iteration of Powersport) include lots of cases of pricing that is
simply out of reach. I like the concept of the rotary or wouldn’t be flying one,
but given the choice between being a beta tester for somebody's brand new FWF
auto conversion versus buying a brand new Lyc from Vans for the same or less
money, I'd choose the Lyc.
Mike Wills
Sent: Friday, March 26, 2010 2:26 PM
Subject: [FlyRotary] Re: Turbo Planning
Mike,
I understand your frustration, nothing is set
in cement as every installation is different.
I have been in discussions with Bill Jepson for
many years now (off list) and now that Bill is in collaboration with Steve and
their refining the old Powersport designs, I sense an era of rapid improvements
for the rotary. Mind you Powersport spent a lot of time and money on their
developments - which showed in their performance. These are optimum
configurations and numbers IMHO.
The beauty of that light engine in size weight and
performance is outstanding IMO.
I do believe that the partnership of Steve and Bill
is outstanding and should result in an offer a FWF package at some
time in the near future for those who don't want to struggle from
scratch. Naturally the accessories might be well beyond what the home
builder is capable of developing/ manufacturing however I believe these
parts will also be available. I know Bill is very keen on direct injection, but
that could be down the track.
All in all the future is looking bright. If we can
pick up ready made and proven accessories or FWF package at a reasonable price,
life would be sweet. Mind you this is just conjecture on my part, at this
point in time, a lot must be accomplished before things are set in cement.
However I'm feeling better all the time, I wish I had more inside information
but Bill is keeping things very close to his chest.
George ( down under)
George,
Your right, my apologies to Bill. It did come across
as pretty gruff. If you've followed previous posts of mine regarding
performance I am very interested in knowing how my airplane stacks up compared
with other RVs, both rotary and Lyc powered. It is hard enough (and very
frustrating) when people post performance numbers at a variety of altitudes,
numbers posted based on IAS or GS without accounting for environmentals, let
alone numbers based on theoretical calculation. How do we respond to critics
of rotary installs without accurate performance numbers?
I'm sort of in the same position as Don. I believe
based on his previous numbers posted that our performance is roughly
equivalent. I know that my performance is currently less than optimum. I have
too much prop for my current HP. I am limited by my gear ratio. I believe I am
giving up some HP due to a less than ideal intake manifold. Unlike Don, I am
content with current performance (for the moment).
I'm looking forward to hearing about how some of these
P-Port engines work out. I am considering building up a new P-port, with
RD-1C, and new prop and doing a swap sometime down the road. In the past week
Paul posted a synopsis of the original Powersport install in their RV-4 and
Alan Tolle's RV-3. I'd forgotten how cool those setups were - it was meeting
Alan and Everett Hatch that sold me on the rotary in the first place. Their
Superlight engine was a work of art. My RV-4 is the best performing airplane
I've ever owned. Imagine what it could do if it had another 70HP and lost 150
pounds (the Powersport RV-4 with Superlight weighed about 860). That should
provide Harmon Rocket performance without having to build another
airplane.
Mike Wills
Sent: Thursday, March 25, 2010 10:25 PM
Subject: [FlyRotary] Re: Turbo Planning
Mike,
Your a hard man, however I do agree
with both the Mazdatrix and Powersport results and would expect their
operating at optimum configuration and 100% VE.
The question in my mind will we all achieve this
in our less than perfect installations - probably not.
I can't remember exactly but powersport was
running two PP sizes, 38mm or 40mm early version and the later 44mm. I
believe Bill Jepson is awaiting the results of a more recent
44mm dyno run. That 210hp may be the old
44mm HP numbers - can't remember exactly. Then again it may be the smaller
inlet as they were running 6,000 for take-off RPM. A smaller PP will give
greater inlet speeds reflecting in VE.
George ( down under)
Sorry, not buying it Bill. If you are going to quote
speeds here, quote speeds, not calculated speeds based on so many variables
that the end result is meaningless. That sounds like something we'd see on
the other list, not here. As far as I know, Don's best reported speed is 174
IAS (and IAS is not all that meaningful either). Based on performance
that Don has actually reported his performance is roughly equivalent to
mine (and I'm both prop and gearing limited). His performance may have
improved since he reported those numbers. In any case I'd prefer to
stick to facts.
Speaking of the other list, Paul has video of a
PP Renesis on a dyno at Mazdatrix cranking out near 250HP @7500RPM.
And he had the dyno sheet to prove it. Powersport claimed 210HP at 2700 prop
RPM (their reduction ratio was around 2.2; roughly 6000 engine RPM). I
believe they also had dyno data to prove it. I'm anxious to hear how Mark
Stietle's PP 20B performs.
Mike Wills
Sent: Thursday, March 25, 2010 6:25 AM
Subject: [FlyRotary] Re: Turbo Planning
Mike,
Don didn’t report speed. I took his pitch and
rpm and figured it. That speed at cruise is what he would get with no
slippage or “lift” from the prop. Most of the folks with the Catto are
actually getting higher speeds than would be calculated which indicates that
the prop is producing “lift”, not
slippage.
But his engine rpm with that big prop are higher
than any I have seen. With the rotary, rpm = horsepower. If you
aint making the rpm, you aint making the horsepower. It doesn’t seem
to matter what you have done to the engine…ported, PP, turbo,
supercharger. If you look at the dyno charts that are all over the
web, you will see that torque is pretty flat after about 4K, about 150 ft
lbs. The horsepower is around 150 at 6K, maybe 180 at 7K, and 200 at
7.5K. You can get more horsepower than that, but only if you scream it
up to 8K or 8.5K. All the charts I have seen are within 10
horsepower of each other at all rpms. The difference in total
horsepower is always a higher max rpm.
We all talk about wanting to cruise at 5800 and make
200 horsepower…it aint happening! Not with the
rotary.
Bill B
From:
Rotary motors in aircraft
[mailto:flyrotary@lancaironline.net] On
Behalf Of Mike Wills
Sent: Thursday, March 25, 2010 1:17
AM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: Turbo Planning
I went back and looked at
Don's previous post. Saw reference to climb performance, RPMs, and temps,
but no speed numbers. Has he previously reported cruise speeds over 200?
Last post from him that I saw with any speed numbers reported 174MPH IAS at
8000. If he's over 200 now, wow those are good
numbers!
Sent:
Wednesday, March 24, 2010 9:15 PM
Subject:
[FlyRotary] Re: Turbo Planning
Those are the best numbers I have seen with anyone
with a Renesis so far. In fact, I have not heard of numbers that good
on any 13B. Don is getting over 200 MPH with a cruise prop and
climbing at over 1400 fpm with it. The only way he is going to do
better is either with an electric CS prop and/or turbo. If he shaves
the prop off to say, 74”, he will get a couple hundred more rpm, but will
probably lose in total thrust. Diameter is a big determiner in
thrust.
I would like more pictures of Dons intake and
exhaust!
Bill B
From:
Rotary motors in aircraft
[mailto:flyrotary@lancaironline.net] On
Behalf Of Al Gietzen
Sent: Wednesday, March 24, 2010 3:05
AM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: Turbo Planning
1. When I read your stats in your first paragraph,
the first thought that
comes to mind is that there is too much prop.
Ditto.
Al
G
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