|
-
POSTING RULES
-
Donate yearly (please).
-
Advertise in here!
-
Today's Posts
|
Insert Pics
|
09-22-2016, 12:23 PM
|
 |
|
|
Join Date: Jul 2013
Location: US
Posts: 2,246
|
|
Air dams and delta-temps
Experimenting with a little aluminum foil tape to find the right heights for the air dams before cutting them down and installing them (made mine removable), and found 1/2" results in a difference in CHTs of about 10 deg F between front and rear cylinders in level cruise at normal speeds. This is in comparison to 25-30 deg difference without the tape. The only issue with this is that the front ones tend to get a bit hotter during initial climb (just over 400, unless I shallow out the climb considerably, or step climb, either of which is manageable).
What would you consider a realistic goal for getting the temps matched up? 5 deg? 0?  I.e., how much "polishing the cannonball" should I do here?
TIA! |
09-22-2016, 02:12 PM
|
 |
|
|
Join Date: Oct 2006
Location: Garden City, Tx
Posts: 5,122
|
|
I'd be quite happy with a 10 degree delta, for me I see about 30-35 delta in a hard climb and about 20 delta in cruise with the front cylinders cooler.
__________________
Greg Niehues - SEL, IFR, Repairman Cert.
Garden City, TX VAF 2020 dues paid
N16GN flying 700 hrs and counting; IO360, SDS, WWRV200, Dynon HDX, 430W
Built an off-plan RV9A with too much fuel and too much HP. Should drop dead any minute now. 
|
09-22-2016, 02:40 PM
|
 |
|
|
Join Date: Feb 2010
Location: Gardnerville Nv.
Posts: 2,828
|
|
How much of the original air dam are you guys flying with, trying to decide if I need to trim some before first flight?
__________________
7A Slider, EFII Angle 360, CS, SJ.
|
09-22-2016, 03:05 PM
|
|
|
|
Join Date: Jul 2013
Location: US
Posts: 2,246
|
|
Quote:
Originally Posted by bret
How much of the original air dam are you guys flying with, trying to decide if I need to trim some before first flight?
|
I put them on for the first flight, and took them off immediately after...much, much too large, blocking too much airflow to the front cylinders.
I haven't had them on now for 400+ hours, but decided to start messing with this a few weeks ago.
I'd leave them off entirely for the first flight and see what you get. And, one of the best pieces of advice I got during the build...make them removable, with screws and platenuts, NOT riveted in! |
09-22-2016, 03:07 PM
|
|
|
|
Join Date: Feb 2010
Location: Gardnerville Nv.
Posts: 2,828
|
|
that's what I did, removable for trimming.
__________________
7A Slider, EFII Angle 360, CS, SJ.
|
09-22-2016, 03:17 PM
|
|
|
|
Join Date: Mar 2014
Location: Laguna Hills, CA
Posts: 1,805
|
|
I removed them completely, after a couple of iterations of cutting them down.
__________________
Doug
RV-9A "slider"
Flew to Osh in 2017, 2018 & 2019! 
Tail number N427DK
Donation made for 2020
You haven't seen a tree until you've seen its shadow from the sky -- Amelia Earhart
|
09-22-2016, 09:04 PM
|
|
|
|
Join Date: Oct 2006
Location: Garden City, Tx
Posts: 5,122
|
|
I've got the stock air dams trimmed about 1/2" lower on mine.
__________________
Greg Niehues - SEL, IFR, Repairman Cert.
Garden City, TX VAF 2020 dues paid
N16GN flying 700 hrs and counting; IO360, SDS, WWRV200, Dynon HDX, 430W
Built an off-plan RV9A with too much fuel and too much HP. Should drop dead any minute now.
|
09-22-2016, 09:13 PM
|
|
|
|
Join Date: Oct 2013
Location: Schaumburg, IL
Posts: 5,281
|
|
I pulled mine, but after getting everything sorted out and broken in, I could probably use a small dam for my #1 jug.
Larry
__________________
N64LR - RV-6A / IO-320, Flying as of 8/2015
N11LR - RV-10, Flying as of 12/2019
|
Posting Rules
|
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts
HTML code is Off
|
|
|
All times are GMT -6. The time now is 01:45 AM.
|
Linear Mode
