8-17-04  .5 hours  /  28.6 total

Flew the rev-3 setup for the first time, and it’s clear this mod isn’t over. 

First, the plane pulls HARD left on takeoff.  Tracy probably saved me from wrecking the plane with his advice to keep the tailwheel on the ground initially to use it for extra steering.  I made two takeoffs, and while not uncontrollable, it’s not what I’d like to end up with.  I’m already planning to shim the mount to get the left thrust out. 

During climb, I needed even more right rudder.  If you let off the pedal, it pegs the ball on the right of the inclinometer.  In cruise, the ball is off to the right about as much as it was off to the left before. 

Climb rpm was only 5650 at 120 mph.  This was just short of 2000 fpm climb, but can’t really be trusted since I had a ceiling of only 1400 ft to work with.  I really didn’t get established in climb long enough to tell what it was really doing.  Temps go up fast now, but again, I wasn’t able to climb long enough to find out just how bad it is. 

I spend some time orbiting the airport at 1400 ft, and about 5000 rpm.  The temps stabilized at 192 for oil, and 158 for water.  I went to full throttle for about 15 seconds, and saw a max of about 28 inches MAP at about 170 mph TAS.  Forgot to note the rpm, but I didn’t let it build up anyway.  Temps go up fast. 

After the flight, I did some full throttle runs on the ground to look at the MAP.  With my current setup using the small plenum I made, I got 5500 rpm (down from yesterday for some reason), at 27.0 MAP.  Removing the inlet tubes from the throttle body gave me 5750 rpm, at 27.3 MAP. 

I didn’t think to check the accuracy of the EM-2 MAP display.  I had a picture of my EM-2 when it was the only thing on, and it read 30.0.  That struck me as odd that it would be exactly 30, then I realized that it gets it’s MAP from the EC-2, which was not on.  I’ve still got to verify this is correct, but bet that it is.

So, what does this leave me with.  First, I’m not getting the 6200 static rpm that I think Tracy reported with his (still unverified) 13B setup.  On the other hand, I must be making considerably more HP than before, because the temps are climbing at an alarming rate, and nothing has been changed on the cooling system, aside from losing the EWP, which has no effect on oil of course.  There is a possibility that my prop is larger in some way than Tracy’s, though that’s a long shot. 

If the MAP readings are correct on the EM-2, I’m losing about 3 inches of MAP in the throttle body alone.  My ports are on the engine side of the throttle body, which is only about 4 inches long.  The throttle body is the same ID as the intake runners, so am I losing 3 inches of MAP every 4 inches of intake runner.  This is depressing, though as always, there's significant room for improvement.