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Greetings=20 all,

Today’s big experiment was to see how the = temps did with=20 a third of the radiator blocked off. =20 The results- I didn’t see any difference at all in = water. The thermostat kept it right = at 180 like=20 always. The oil seemed a = bit cooler=20 though. That would sort = of make=20 sense, because I blocked off the part of the radiator that wasn’t = below the oil=20 cooler. Perhaps that = forces more=20 air through the oil cooler. =20

While trying to decide whether to = block off more of the radiator, or block = part of the=20 inlet (currently 19-1/8 wide, by 4-1/4 tall), I started looking at the = outlet=20 area. I have the back of = the cowl=20 cheeks opened up as the primary air outlet, but there’s also about = 2” open over=20 the top of the radiator at the rear of the engine compartment. Because of the horrendous = angle that air=20 would have to turn, I figured that little air was going up through the = radiator,=20 then turning 90 degrees and heading out the bottom of the cowl. I only left this area because = I thought=20 I might need the space over the radiator for a fan. I took a big floor fan, and = put it in=20 front of the cowl opening, and was mighty surprised to feel that most of = the air=20 seems to be coming out the bottom opening, rather than the cowl = cheeks. Since this bottom opening will = be closed=20 up in my proposed Rev-2 cowl, I decided to make a cover to temporarily = close=20 off the rear of the cowl at the=20 bottom. This will force = all the air=20 to go out the cowl cheeks as I originally intended. The next flight will = tell me if=20 this works or not. =

Good=20 news, there’s no more oil on the belly. =20 There was also no oil in the collection tube, so the problem on = the last=20 flight was simply that there was a vacuum pulling the air out of the = vent=20 line. Proving the = existence of the=20 vacuum at my bottom cowl opening is what made me start to worry that my = lower=20 air outlet was doing far more than I imagined.

I did a 4 way run to check the GPS readings = against my=20 ASI. At 3000 ft, and 5 psi of boost (38" MAP), I recorded an = average=20 GPS reading of 166 mph for TAS. I consider this pretty good, for = BUC, and=20 the lack of wheel pants and gear leg fairings.

This week, I plan to try to port the = wastegate, and=20 will hope for a full throttle, 5 psi run next weekend. Should be = cooking=20 with gas if I can manage that.

Cheers,

Rusty

PS- congrats Tracy!!!

PPS- Now get back to work on my EM-2 :-)=20