Greetings
all,
Today’s big experiment was to see how the temps did with
a third of the radiator blocked off.
The results- I didn’t see any difference at all in water. The thermostat kept it right at 180 like
always. The oil seemed a bit cooler
though. That would sort of make
sense, because I blocked off the part of the radiator that wasn’t below the oil
cooler. Perhaps that forces more
air through the oil cooler.
While trying to decide whether to block off more of the radiator, or block part of the
inlet (currently 19-1/8 wide, by 4-1/4 tall), I started looking at the outlet
area. I have the back of the cowl
cheeks opened up as the primary air outlet, but there’s also about 2” open over
the top of the radiator at the rear of the engine compartment. Because of the horrendous angle that air
would have to turn, I figured that little air was going up through the radiator,
then turning 90 degrees and heading out the bottom of the cowl. I only left this area because I thought
I might need the space over the radiator for a fan. I took a big floor fan, and put it in
front of the cowl opening, and was mighty surprised to feel that most of the air
seems to be coming out the bottom opening, rather than the cowl cheeks. Since this bottom opening will be closed
up in my proposed Rev-2 cowl, I decided to make a cover to temporarily close
off the rear of the cowl at the
bottom. This will force all the air
to go out the cowl cheeks as I originally intended. The next flight will tell me if
this works or not.
Good
news, there’s no more oil on the belly.
There was also no oil in the collection tube, so the problem on the last
flight was simply that there was a vacuum pulling the air out of the vent
line. Proving the existence of the
vacuum at my bottom cowl opening is what made me start to worry that my lower
air outlet was doing far more than I imagined.
I did a 4 way run to check the GPS readings against my
ASI. At 3000 ft, and 5 psi of boost (38" MAP), I recorded an average
GPS reading of 166 mph for TAS. I consider this pretty good, for BUC, and
the lack of wheel pants and gear leg fairings.
This week, I plan to try to port the wastegate, and
will hope for a full throttle, 5 psi run next weekend. Should be cooking
with gas if I can manage that.
Cheers,
Rusty
PS- congrats Tracy!!!
PPS- Now get back to work on my EM-2 :-)