It IS good to seal that area behind the spinner but for a different reason. I was trying to improve cooling one day and sealed around the neck of the drive. Cooling got ever so slightly worse but my airspeed at the rpm I was testing at go BETTER (by about 2 mph). The reason was that the spinner was pumping air out of the cowl at the spinner gap (mine was pretty big, about 1/2") and creating drag. But since the air was being drawn from behind the rad, it improved cooling a little. I was glad to make the trade because a solid 2 mph is harder to come by than the little bit of cooling that it gave up.
Tracy
Sent from my iPad
I didn’t see any input when I last asked this
question, so I will try now that we are again talking about cooling.
How are you sealing around the PSRU outlet
on the cowl? I am talking about the area behind the spinner. This area allows
air to enter behind the heat exchangers and it seems to me that it would adversely
affect cooling. This area is open on my plane because I haven’t figured out
how to seal it. I am wondering what others have done?
Bill B
From: Rotary motors in aircraft
[mailto:flyrotary@lancaironline.net] On
Behalf Of Ed Anderson
Sent: Friday, August 31, 2012
11:56 AM
To: Rotary
motors in aircraft
Subject: [FlyRotary] Re: FIRST
FLIGHT N655HC
I would completely seal any leaks around the sides or
anyplace else that could leak between duct inlet and radiator. I read
someplace that a 1/2"square hole could cost you 20% of your cooling
effectiveness.
A gent who once sold Subaru engine installations
tried just sticking the radiator in back of the opening (no ducting) - did not
cool.
Yes, I find that getting the airflow up as soon as
safely possible will help a great deal in keeping temps down and bring them
back down quickly. My magic airspeed after take off is 120 MPH IAS then a
140 IAS for climbout.
Looking forward to more reports
Sent: Friday,
August 31, 2012 11:01 AM
Subject:
[FlyRotary] Re: FIRST FLIGHT N655HC
Congratulations, David. I hope to be following
you soon.
Are you able to cool on the ground? What did you do to improve the
cooling between the two flights?
On 08/30/2012 10:48 PM, hoursaway1@comcast.net
wrote:
Thanks Mark, it was
kind of anti-climatic for the others on the ground because they already saw
that last month, but for me seeing the temps coming down at about the same
stage as Terry saw them still climbing was comforting. I'm setting up a
video camera to record the panel so I can focus on flying for now until I get
more comfortable. We have a 100 mile radius to work with & I
asked for & was granted a crew member during the flights
that computer tuning will be worked on. Tryed to get a stewardess
also but FAA said no. ???? Yes I read Ed's procedure
for takeoff & our sys. is very similar so will use for next
flights. Terry is a member of our EAA Chapter 55 here in Mason
MI, his dad just flew his 400 th Young
Eagle.
( where is that stewardess
with my Margarita )
David.
From: "Mark Steitle" <msteitle@gmail.com>
To: "Rotary
motors in aircraft" <flyrotary@lancaironline.net>
Sent: Thursday, August 30, 2012
7:44:53 PM
Subject: [FlyRotary] Re: FIRST
FLIGHT N655HC
David,
Congrats!!! Job well done. Terry Lutz...
WOW!
What was the OAT? I start to get nervous when
my coolant temp goes above 200 F. No reason to climb at WOT if not needed
and OAT is high.
Mark S.
On Thu, Aug 30, 2012 at 6:07 PM, <hoursaway1@comcast.net>
wrote:
First flight for me anyhow not for the aircraft,
Terry Lutz ( AKA;; world renowned professional test pilot, flew in from France to do
the First, First flight )
Temps went;; coolant 221 F max, oil 210 F
max, on full throttle clime out up to 2000 ft., powered back from 6300
rpm to 5000 rpm/135 mph indicated, push the nose over to level off, pulled
power back to 4500 rpm ( made no prop pitch changes at this time
) temps went down to;; coolant 195 F, oil 190
F, this is without therm. & bypass blocked, also would like comments
about sealing around sides of both radiators, we saw the extra fins there so we
allowed air to pass through that area, may install a temp seal & recheck
data points next flight. Then possibly install venting openings in bottom of
cowl to let more airflow out quicker. David R. Cook
RV6A Rotary.
From: "Joseph Pirch" <pirch@sbcglobal.net>
To: hoursaway1@comcast.net,
"rv man2010" <rv.man2010@hotmail.com>
Sent: Wednesday, August 29, 2012
8:40:58 PM
[image/jpeg:photo.JPG]
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