|
|
Chris,
My rpm doesn't go down at WOT during a runup, but it does hit a
ceiling. If I tweak the mixture knob to the right about 1/4 turn the
rpm goes up some more. You might try that. There are some differences
in our numbers, though - I get about 5800 rpm full fine on a 66" 3
blade IVO with 42 MAP. Part of this could be differences in the aspect
ratio of our turbos. You'll also notice that the rpm will climb as your
speed builds. My 5800 will translate to 6300 in climb-out and, if I'm
heading out of the pattern and there's no 172 ahead, I'll add a bit of
pitch to the prop at this point to bring the rpm back down, and the
speed up.
Regards,
John
Chris Barber wrote:
I know this must have been discussed, but perhaps more in
passing or in some of Tracy's literature (now kinda dated, especially
with some of the strides he continues to make), but what is the
conventional wisdom as to rotary horsepower? I know when I first
started looking into it, oh many years ago, it seemed the impression I
got was that you could pretty easily achieve 200 hp, however, that is
now a bit lower. Some of the tricks to get the higher HP was mild and
medium porting, bridge, "J" and "P" porting. Then there was the option
of turbo...the one, in combination with a medium street port, I chose.
What say Ye?
When started today, mine was turning about 6200 rpm at 35 MP
(with a 3 lb spring in the wastegate).....it surged forward against the
chocks and breaks. IVO prop full fine. Nice feel of power even if it
likes to heat up fast in 90 degree weather like this.
Also, I think this was discussed before too, when I go WOT my
engine develops up to about 6250 rpm, but then drops a couple/few
hundred rpm to usually just under 6000....sometimes just above.
Thoughts? Ed, (perhaps Al)it seems you may have chimed in before.
Regrettably, when I search the archives I tend to get frustrated due to
thread drift.
I heard a lot about porting when I was initially investigating
all this and I chose to use a medium street port. I let Mazdatrix do
the work. That being said, I have read all but nothing on others
porting their engines (other than a LOT from PL on P ports). Since
standard porting does not reportedly effect reliability, only,
potentially low low idle (I can idle as low as about 1300 rpm when warm
smoothly) why is it not discussed and/or utilized more?
Just curious guys/gals. Discuss <g>
All the best,
Chris Barber
Houston, GSOT
Always loved
the lines of a Tailwind – in fact, I have the plans and license to
build a W-10 sitting on my book shelf. Unfortunately, I doubt I’ll
ever get around to it.
Ok with
thermostat in the system holding it at 190F – we really won’t know how
much reserve capacity you have in your cooling system until the power
goes up.
I agree with
George, 200HP out of an N/A 13B is really pushing it. I think 180HP is
a more realistic expectation – but, hey you never know. It amazing how
power goes up when things come together.
Enjoy and
fly safe.
From: Rotary motors in
aircraft [mailto:flyrotary@lancaironline.net]
On Behalf Of John
Sent: Wednesday, May
26, 2010 2:36 PM
To: Rotary motors in
aircraft
Subject: [FlyRotary]
Emailing: 3 view w-10 003, first flight
My most humble thank you
to flyrotary and all you fine folks that have helped bring my project
to flight. Ed and many others whom I won't try to name here because I
would miss many. The plane is a Wittman Tailwind W-10, empty wt. is
981 and it is a tri-gear, Wt. is within 6 #'s of similar trikes w/
0-320 engines. I have the thermostat in the engine because most of the
year it is not very hot, if we get 50 days with the temperature over
70, we have had a hot summer, not a lot of beach bunny activity. 7-1
I'll be 74 and have realized my dream, now it's all gravy. Again,
thanks guys!! JohnD
Your
message is ready to be sent with the following file or link attachments:
3 view w-10 003
|
|