|
Thank you for the responses to this problem, I
learn something new every time.
All I wanted to say with my story is that
sometimes the problem is not where you expect it to be.
The Griffin cooler was installed exactly where the
RX7 cooler was in the first place. I replaced the RX7 cooler with the
Griffin cooler. I had to modify the duct to accomodate the larger cooler,
otherwise the ducting remained the same. The first try of the
Griffin cooler was without a fan. Then I tried with the fan -- no
difference. Then I built a oil/water exchanger and installed it in series
with the Griffin cooler. There was some improvement in the oil temp
but not enough. That is when I removed the Griffin cooler and fan and
replaced it with the RX7 cooler that I had in there in the first
place. I kept the oil/water exchanger in series, this time
with the RX7 cooler.
I agree that if air flow was the problem the exit
air temp would be high, mine was low.
There is no by-pass air flow, the duct is
sealed.
The Griffin cooler, like the RX7
cooler is a double pass with both in/out on one end.
Now the story has
changed, last landing I made (oat about 35) the oil and water temp were
about 120 deg F -- too cold for my taste.
I always wait for the
oil to reach 140 deg F before takeoff. I do not want to run the engine
with the oil below that temp. So I am building louvers to control the air
flow to the two radiators. And that is with the water rad plastered with
duct tape and the oil rad air flow restricted to a 12 cu. in. air
exit.
Rino
----- Original Message -----
Sent: Friday, October 30, 2009 8:13
PM
Subject: [FlyRotary] Re: Cooling report
Rino, any
comments on the Griffin oil cooler
location and inlet ducting Vs the RX7 oil cooler location and
ducting?
If oil flow was
not the problem it must have been air flow.
Jeff
If there was
not sufficient air flow, then the air outlet temp would be very high, not
very low – unless the temp number is not correct, or there was a great
deal of by-pass flow.
Re: Here is my
fan installation. It is a 4-blade, pull, high flow, Spall. The
inlet scoop is sealed to the other side of the rad. I don’t know
whether it spins in flight when turned off, but there is no evidence that
it does. It works fine after 160 hours in flight. If it is a concern, one
could always use a relay that shorts the leads when turned off serve as
electromagnetic brake. A spinning fan would be more restrictive to
flow being forced through it than one that is stationary – contrary to
one’s intuition.
Al
|