Speaking of tuning.
I'll tell you I was impressed when Dave Lemon slapped a 58 mm
downdraft Weber on our p-port engine and got over 240 HP right out
of the box at 6800 to 7300 RPM. I never did get the EFI to work
right on the dyno.
Paul Lamar ...No rotor no motor.
I'm new to your list so please bear with me if the answer to these questions
are well known:
1. Do you have any read material explaining what mods you did to this specific engine.
2. Except for carb heat & cooling requirements, can this engine be used in
a flying configuration with the current intake system as is? (240 HP without EFI
sounds excellent!)
3. Is the P-porting done in the standard way?
Regards,
Hennie
1. Yes we do. We have a bunch of pictures and other stuff. Start by looking at all
the stuff on:
http://www.rotaryeng.net/intake.html
And then get back to me with specific questions.
2. Not really. You need to put a couple of aircraft carbs on there
capable of being leaned and handling about 130 HP each.
A pair of Ellison Throttle Bodies would probably work.
http://www.ellison-fluid-systems.com
Two EFS-3A's might work.
The runners must point down as most aircraft carbs are up draft.
that will preclude the muffler under the cowl so the muffler will
become external under the fuse.
3. See
http://www.rotaryeng.net/intake.html
Paul Lamar
Paul,
I've followed your discussions for a month or so and read all the recommended stuff on
the links as mentioned. I do realize that there are prove and correct ways to
install a rotary engine in an aircraft and I am not at all trying to debate that.
I am just curious though. The intake system as in your pics looks so simple and yet
seem to surprise even you. Is there therefore no way that such a simple system, giving
such high HP (I realize it's about more than just dyno measured HP) can be applied
with only minor mods like carb heat, as is, into a flying configuration?
I've read recently in this list that the Weber sort of does it's own leaning and/or
altitude compensation by default in it's standard form. (apparently just the way the
carb works in it's natural state)
At an air show in South Africa, I saw a flying rotary installation without the normal
oil cooler and this builder informed me that he mixes his normal automotive fuel
with car oil for lubrication. Is this method used in more installations or is this
just looking for trouble, even if done properly?
Best regards,
Hennie
The Wankel rotary engine is intrinsically simple. That is the real genius behind it.
The p-port modification is also very simple and it simplifies the intake
manifold to only two runners while at the same time removing the impediments
to airflow entering the engine. The easier it is for air to enter the engine
the more power it can generate and the less fuel it will burn to generate
that power. Same goes for exhaust gas exiting the engine. Those are called
pumping losses.
I was not surprised about any of this. I was surprised
at how quickly Dave Lemon and crew at Mazdatrix could tune it so rapidly.
Probably took all of five minutes. However as Bill pointed out they
have years of experience with Weber carbs on Mazda rotary engines.
According to Ken Welter the Weber can be tricked into compensating for
altitude but that feature is not built into a Weber. I have heard rumors of
carburetors that can automatically compensate for altitude but I am not
familare with them installed on an aircraft engine. I think the SU carb
found on old British cars might be one of them. My experience with SU carbs
on the other is such that I would not let one of them get within ten feet
of my airplane :) Most carbs on aircraft engines use manual leaning controls.
There is a kit that will convert a four barrel Holly carb to manual leaning.
I think what you saw was a rotary engine with the problematic oil injector
and associated plumbing removed. In that case it is more reliable to mix
oil with the fuel to lubricate the all important apex seals.
It is as close to impossible as impossible becomes to use a rotary in
and aircraft without oil cooling. Oil cooling makes up one third of the
rotary engines cooling needs.
Paul Lamar ...No rotor no motor.
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