Mark,
 Hows is the p-port 3 rotor going?

 Paul



 Mark Steitle wrote:

 Hi Paul,

 The 3-rotor is coming along just fine.  I flew it last Sunday after
 replacing the water pump (old pump started dripping coolant from the
 shaft/seal).  However, I replaced it with a spare 20B pump, not the
 Renesis
 that I've been working on.  That will come later.  I'll be sending you $
 for
 an inlet/outlet adapter.

 As for how it is running, I would say it is running fair.  It is rough at
 around 2000 rpm.  I'm seeing a low EGT on rotor #1, which I will try to
 adjust using EC-2 mode 4.  If I can't get it to adjust, I will have to get
 the injectors cleaned.

 You may remember that I'm running 3 MSD 6-A ignitions.  Those are working
 out great, but I'm not convinced they're worth the weight penalty.  I've
 started the engine and heard it running on 2-rotors (fouled plug), only to
 clear up a few seconds later.  I checked the plugs after Sunday's flight
 and
 they looked better then the trailing plugs which are still being fired by
 the EC-2.  So, I don't think the plugs will have any trouble handling the
 multi-spark environment.  But then I took it easy as I've made a number of
 changes lately and I'm still a little nervous.  It starts similar to the
 old
 engine, except it requires less fuel (no priming).  I turn the mixture
 knob
 to about 3 o'clock position and hit the starter, then return the knob to
 12
 o'clock once it starts.  Very nice!  Once warmed up, just hit the starter.

 One of the biggest successes is the new tangential muffler.  It is much
 quieter than any of my previous mufflers.  However, it was beginning to
 bubble the paint on the lower fuse, so I had to add a turn-down piece.
 Solved the problem.

 One side note... my old engine was plagued with oil leaks.  I think the
 oil
 was seeping through the base of the housings (the area between the oil pan
 flange and the outside the o-ring perimeter).  I didn't use any sealant in
 this area when assembling my first engine.  This was a big mistake.  Lynn
 H.
 pointed out that this is a common mistake from novice rotary builders
 (thanks Lynn).  So, I used Hylomar on these areas on my new engine... and
 no
 leaks!  Life is good!

 Cooling seemed a little higher than I would have liked to see on climb
 out,
 but they came right down once I leveled off.  OAT was 78*, oil got up to
 205, but dropped to 175 in level flight.  Water was 157* in level flight.
 But I was running it easy, so I'll be watching the temps very closely in
 future flights.  In retrospect, I climbed out at 85 rather than 110 like
 usual.  So, I'll have to keep the speeds up and see how the temps look.

 See ya,
 Mark

 Glad to hear it about the muffler. Sorry about the pun.
 Does it have the central cooling tube?
 Picture?

 Paul


 There is no cooling tube as the oil cooler is too close (need to move that
 forward).  However, it does have an internal baffle (inconel 625) that
 consists of a tube which has 109 1" diagonal slits cut in it.  One edge of
 the slits was then dimpled inward to form 109 D-shaped holes for the
 exhaust
 to exit through.  I can inspect the inner baffle with an inspection camera
 through the three inlets.

 Mark


 I think we need to add that muffler inspection procedure as a
 preflight inspection. The length of the inspection camera neck
 is 3 feet long so keep that in mind when designing your exhaust
 system. If you use the cooling tube that would allow external
 inspection of that device.

 You don't want this to happen to your muffler.
 Cheap insurance for $100.

 Paul Lamar


 Yes, I already have the inspection camera.

 Mark

 UPDATE:  After an inspection of the deep dark bowels of my tangential
 muffler, I flew for about 45 minutes today.  Temps on the ground were in
 the
 upper 80's, at 3000 MSL the OAT was 68*-70*.  I climbed out at 105kts
 indicated and oil temps stayed around 195*F, water was 175*F.  (I measure
 the oil temps out of the engine as well as the return oil temps.  The oil
 out temp was 235, so I was dropping 40* through the oil heat exchanger.)
 After leveling off, the temps dropped down to 160-165* for coolant,
 170-175* for oil.  I confident that at normal cruise altitudes (8-10,000
 msl)  the oil temps should be down closer to the magical 160* number.

 There must have been a piece of crud in one of the injectors for the #2
 rotor because the EGT was 400-500* lower than the other two.  The #2 EGT
 gradually increased and finally got to where the other two were at, approx
 1600-1650*.

 It still needs some tuning but a low ceiling prevented climbing above 3000
 msl.

 All in all, a good flight.

 Mark S.

 What kind of performance numbers and fuel burn are you seeing Mark?
 Rate of climb? Cruise speed. Cruise RPM. Max RPM?

 Are there two injectors per rotor or just one?

 Paul Lamar


 Paul,

 Yes, two injectors/rotor.  I don't have any performance numbers as I am
 not
 pushing it, but taking it easy.  My gut feel though is that the tangential
 muffler may be hurting performance.  Lynn H. commented that the p-port is
 very sensitive to exhaust back pressure.  I'll do some speed runs later,
 after the engine is broke in (100 hrs or so) and post the numbers.

 BTW, as it applies to the Everett Hatch award, I was wondering if you
 would
 recognize a win in a sanctioned race by the Sport Air Racing League,
 assuming an average speed of 225 mph  or more?  My n/a 20B Lancair ES fits
 nicely into the Sprint class as it is 1) less than 240 cu. in displacement
 and, 2) normally-aspirated.  Or, I could also fit within the FX-Red class,
 which is 1) less than 320 cu. in. displacement, 2) normally-aspirated, 3)
 at
 least two fixed gear.  But I would be handicapped by displacement, so I
 would probably run in the Sprint class.  That's assuming this p-port motor
 works out as planned.

 Mark S.

 We had not considered that as the Dayton to OSH 500 mile race gets a lot
 more ink. The race winners are displayed in a special paddock near the
 center
 of the air show. The goal is to show off the performance of the
 rotary. However if you use 300 HP on average to go 225 MPH with a
 BSFC of say .6 your fuel burn would be 180 pounds per hours.
 Total hours for 500 miles would be about 2.25 so that would be 405
 pounds of fuel or 65 gallons of fuel.

 How much does your tank hold?  Most ES's are 105 gallons.

 So you should be able to do that no problem. The RV's are short
 on fuel tankage so they would have a problem running that race.

 We tested the 13B p-port it on the dyno with two exhaust pipes
 32 inches long into one. And then a muffler after that.
 That is roughly the same as Everett Hatch used to run with his
 p-ports. We are not looking for 150 HP per rotor at 10,000 RPM
 as the road racers need. I think we can get along with a bit
 more back pressure. All we need is 125 HP per rotor.

 We ran the tang muffler and it seemed to run OK
 but it was too noisy to do any sustained high power runs.
 Note the huge rectangular down pipe which Mark Sus has now made
 smaller.

 Mark Suspinski is going to measure the pressure in
 the tang muffler as soon as he has
 solved another issue.  The best way of doing that is use
 that Hytech Automation data acq system (Mark Sus still has it)
 and a Free Scale pressure sensor.

 Weld into the muffler a two foot lenght of steel
 brake line tubing with a bunch of tiny holes drilled around
 the inside end. That will form a static pressure tap. Use silicone
 rubber hose good to 500 F to connect the cool end of the steel brake
 line to the Freescale pressure sensor. You could  also use an absolute
 pressure gage that reads out to 30 psi. Kind of like a supercharged
 radial engines manifold pressure gage that reads to 60 inches of HG.

 Don't try a water manometer as 12 inches of water is only .45 psi.
 You would need one 50 feet high :)


 Paul Lamar


 Paul,

 Well, then I guess I could run a race or two by the Sport Air Race League
 so
 as to collect some good performance data.  My ES holds 94 gallons of fuel.
 Should be enough for 500 miles.

 Steel brake line tubing would last about a minute inside the tangential
 muffler.  We would need 321SS at a minimum.

 Mark S.

 Depends on where you put it. Off in a corner would be the best place.
 I have not found small 321SS tubing yet. It only needs to last a few
 minutes  anyway.

 These look like 100 mile races. They look easy.
 http://www.sportairrace.org/id317.html

 I think you will be at a disadvantage with a Hoffman or MT prop.
 It is a real shame we don't have a hyd prop psru that can handle
 metal CS props. So much to do and so little time :)

 Metal props go faster than carbon or wood. I don't know
 why people make carbon props so thick at the tips. In theory
 they could be made as thin as metal.

 Paul Lamar

 Paul,

 I could reach VNE (220mph) in straight and level flight with my old motor
 running the 3-blade M/T prop.  So, where do I go from there?

 Mark S.

 More power does not help top speed much. However you should see
 a dramatic improvement in climb rate. Top speed is proportional to
 the cube of HP. Drag (K) is what top speed is all about.

 Assume for the moment you had 275 HP and you went 220 MPH.

 (275)^.333333 X K = 220

 ^.333333 means cube root in computer language.

 K = 220/(275)^.333333 = 33.83

 (New HP)^.333333 X K = New top speed.

 HP    Top Speed MPH
 250......213
 275......220
 300......226
 325......233
 350......238
 375......244
 400......249

 With 375 HP (in theory) you would go 244 MPH.
 Also depends somewhat on the actual twist and tip airfoil of your
 constant speed prop. The vector sum of circumferential tip speed
 and forward speed changes at the same RPM.

 Looks like this would be a piece of cake for you Mark.
 Unless Tracy gets in the race first with his 3 rotor RV8 :)

 Maybe we will have to raise the average speed to 240 MPH for the Everett
 Hatch
 Memorial $1000 prize :) Just kidding. Nobody has won the 220 MPH $1000
 prize yet
 but Tracy Crook has come close at 214 MPH in the Sun 100 a few years ago.
 Unfortunately they did away with that race.

 BTW Kit Planes magazine should pick up on this:

 http://www.sportairrace.org/id317.html

 Air racing. I'll send an email to Marc Cook as he will be publishing
 another one of my articles  soon.

 Paul Lamar

 Paul,

 I was considering racing in the Taylor 100 as Taylor, TX is near Austin
and
 so this would be an easy event to participate in.  Dayton to OSH would
 require a much bigger effort.

 A question on horsepower... If your engine loses 40% of its power at
 altitude, wouldn't starting out with more horsepower at sea level equate
to
 higher speeds at altitude?

 Mark S.

 Yes and that is the rational for Mark Sus's P-port as his airport is 8000
 foot density altitude. The jury is still out on how it is working
 as his prop is yet to be optimized. He basically has a fixed pitch 172
prop
 on there and I suspect the tips are going into a negative angle of attack
 at 150 MPH. When he dives the engine does not pick up any RPM.

 Paul Lamar



 Paul,

I visited Mark when I was in Denver and checked out his project (wasn't
flying at that time), and he checked out my 3-rotor installation.  Good to
hear that he's flying, but would like to hear more.  Maybe he could borrow
a
prop from someone on the field.

Mark S.

He redid the oil cooler ducting as oil was running
too hot. It was mounted horizontally behind the engine
and he moved it along side the rad under the engine.
He thinks it is working much better but he has not flown
that configuration yet.

He thinks he has a stuck starter right at the moment.

He also plans to start over on the tuning. It appears
to be out of wack. We thought at first it was fuel starvation
but that has been ruled out by checking the pressure at
the fuel rail.

He is going to "slavishly follow Tracy's tuning instructions and
see if it results in different behavior".

We both agree a PC interface  with a visible fuel map would be better.

Ed Anderson showed me his fuel trim map at Sun n Fun and I was
surprised at how non uniform it is. I forgot to ask Ed where is manifold
pressure tap was located. I'll send him email and see if he will tell
me.

Mark Sus is using the oil injector holes pressure taps.

What does your fuel trim map look like Mark S.?

Paul Lamar


My map table is still a "little out of whack" also.  But not so much so
that I can't fly.  It just requires some adjusting of the mixture knob for
the various modes of flight.  I was going to fly today and do some
auto-tuning, but the weather didn't cooperate, so that will have to wait for
another day.  So, I can't say for certain what it looks like at the moment.
Doesn't Mark Sup have an EM-2.  If so, he could (should) let it do the
tuning for him.  (I speak from experience on this.)  Mark Sup needs to
understand the layout of the table.  Addresses 0 through 31 mixture is
determined by RPM (up to 2500 and under 13" Hg); Addresses 32 through 63
correspond to 2500 - 3800 rpm and MP greater than 10" - MP determines MAP
table address; MAP table address 64 through 127 (above 3800 rpm) are
determined by MP.  (No wonder everyone gets confused.)


Also, I recently installed a wide band O2 sensor.  This is far superior to
the mixture bar on the EM-2.  With a digital readout, it makes tuning much
easier.  Early on I resisted because of the price ($300-400).  But after
using it to tune my 20B, I am now a convert.  I highly recommend the wide
band O2 gauge.  Functional EGT's is also a must.  I've recently had to
replace two fuel injectors as evidenced by rough idle/off idle and low
EGT's.  Without the EGT to give me a hint as to the problem, I would have
had a much harder time determining the problem.

The bottom line is that you can't tune an engine that has other problems.

Mark S.