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Mike,
Paul L. insists that the 2"PP is the way to go,
because of the LeMans configuration. My maths says otherwise - because of the
lower inlet speed at our RPM. I am encouraged by the Powersport inlet sizing,
but still awaiting the latest dyno figures.
George ( down under)
----- Original Message -----
Sent: Saturday, March 27, 2010 3:57
AM
Subject: [FlyRotary] Re: P-Port
performance
"I'm looking forward to hearing about how
some of these P-Port engines work out."
This is the only current
flying P-Port that I know of. Same engine that Paul L. talks about that
he Dyno tested at Mazdatrix. Here are a few clips from Mark Supinski's
Mustang II w/ P-port 13B first flight tests. Hard to draw solid
conclusions from first flight especially at that altitude but the max
rpm with that small prop do not look all that good. There may be a lot
more potential when things are worked
out.
Tracy
K00V - Meadow Lakes Airport, Peyton
CO
OAT: 50F
Winds: 5kt out of north
Field Elevation:
6875
Density Altitude: 7680
Mazda 13B rotary, NA with Peripheral
Porting
2.85:1 redrive, standard prop rotation
Takeoff
roll
was 1500 feet max;
Water temps throughout the climb were a chilly 178F
max.
Oil temps were not as kind, 197F on takeoff, 217F when departing
the
pattern, and 241F at 10,000 feet. Oil temps quickly dropped back
to
215F on level out,
Maximum
rpm was around
7000 (~2450 prop). Given that our prop is only a
68x68, we would
expect to be able to get to the electronics limit of
8000
On Fri, Mar 26, 2010 at 12:58 PM, Mike Wills <rv-4mike@cox.net>
wrote:
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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