P-port engine tuning

Paul:

I haven't seen anything about your plans regarding Oshkosh this year. If
the newsletter is going to be operational between the 23rd and 29th,
please
hold any messages during that interval. I will be at OSH all week,
returning home on July 30th. No, the ES isn't going. It is in the paint
shop.

Tom Parkes

Are you flying your Lancair ES turbo 3 rotor Tom?

I think I am leaving on Tuesday morning so the newsletter will be shut
down then.
On the way back I'll stop in Denver so I can be at Marks Hangar on
Saturday morning. Hopefully Doc will be there with a scope and Mark
himself can make it. That gives us two days to get Mark's p-port engine
tuned up
before Mark has to go back to work on Monday. I'll bring a spare Tracy
computer
so we can tap off the intake manifold pressure sensors.

--

Somehow I think I can make the lonnngg 27 mile drive to the airport if
you're willing to take the short 1000 mile ride. ;-)

Mark (Rocky Mtn High)

I'll be there. I am flying the tubes :)

Paul Lamar ...No rotor no motor.

I am planning on being there. I hope the scope arrives by then.

We are talking about July 28th, right?

Doc Custer
Retired Software Engineer and sometime Audiologist

Correct Doc.

--
Paul Lamar ...No rotor no motor.

If I don't make it for some strange reason (I am flying standby)
you will need some tiny test clips to grab on to Tracy pressure sensor.
You can buy them in Radio Shack, Mouser or Digi Key. I'll pack some
but just in case you should get some.

Measure the pulse close to the intake manifold and compare it with
the output of the vacuum can going to the pressure sensor.
Tracy has two pressure sensors so one can be used to run the engine
and the other to the output of the can or vice versa.

Larry suggested a coil of 1/8th OD tubing works well to damp
the pulses. Worth a try.

Any questions?
--
Paul Lamar ...No rotor no motor.

Mark, if you get a chance next week please solder up a 37 pin D sub min for power
and gnd for my computer. Then we won't have to open up yours to
get to the pressure sensors. That is if I make it there.

Here are some more pictures.
--
Paul Lamar ...No rotor no motor.

OK I made it.

I won't keep you in suspense.

Mark, Doc and I got the slide throttle P-port EFI 240 HP engine running. I was very happy indeed.
No problems. We changed three major things. We installed a $7 mechanical fuel pressure
gauge which, IMHO is absolutely necessary when you are first starting up an
EFI rotary engine. You need real confidence in these sorts of things. You can't
be messing around with some EFI sensor you are not sure is really telling you the
truth. We set the fuel pump pressure up from 35 psi to 60 psi. Changing the pressure
changes the whole look up table up or down. Up for richer down for leaner.
In and of itself this did not help. We installed a pulse damper can in the vacuum
line to the pressure sensors. The results of this so far are still indeterminate.
The biggie was setting the timing correctly. More about that latter. Once we did that
the P-port engine fired right up with less than two blades and ran smoothly at about
2000 engine RPM (700 prop RPM). We pushed it out of the hangar and started it up
again. Again no problem. We had it up to 4500 engine RPM. We started it two or three times
no problem. Each time it started right up and ran the same. The altitude at Marks
hangar is 6000 feet.

It was getting late so we stopped and went home while we were ahead. Mark probably
went out to the hangar on Sunday and ran it some more so I can hardly wait to get
his reports. I left early Sunday morning. Thanks for dinner and putting me up Mark.

Thanks Doc for showing up with the bit scope. Unfortunately we did not get the
engine running in time to do R&D on the intake manifold pulse problem.
It is running fine with the pulse damper can so we can leave it at that for now.

Paul Lamar ...No rotor no motor.

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