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  #1  
Old 10-03-2013, 05:54 PM
08FATBOY 08FATBOY is offline
 
Join Date: Mar 2013
Location: STRONGSVILLE OHIO
Posts: 31
Default oil cooler spacing

I have less than a 1/2" of space between the oil cooler and muffler. I haven't epoxied the duct to lower cowl. Anyone have an average measurement for this.
I have seen a photo of the duct cut out. Does anyone have better photos and possibly instructions or dimension to do the job? Need help as fiberglass repair is not one of my strong points. Thanks for your help!

Rod

Last edited by 08FATBOY : 10-03-2013 at 06:26 PM.
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  #2  
Old 10-03-2013, 06:37 PM
RGaines RGaines is offline
 
Join Date: Aug 2007
Location: Novato, CA
Posts: 151
Default cooling

If you have not fixed its position yet, change it so that you can get 1" at least. I had about a 1/3rd of an inch and lots of hot oil readings. I moved it about 1 inch forward and solved all of the cooling problems. Sorry I don't have pictures but if you search for oil cooler mod you will find them.

Richard
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  #3  
Old 10-03-2013, 07:00 PM
Bob Kibby Bob Kibby is offline
 
Join Date: May 2008
Location: Arlington, Texas
Posts: 127
Default Concur, you need more space

I had major oil temperature problems in our Texas summer heat. Not being able to directly measure my spacing I took several measurements from the firewall and determined that I only had 1/8 inch spacing between the oilcooler and muffler. I moved the oil cooler 1inch further forward with the lower cowling mod and have had no more oil temperature problems in our 100 f + days. IMHO you need at least 1inch between the oil cooler and muffler if you fly in The Texas summer heat. In the 90's today.
"2BK" 165 hrs
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  #4  
Old 10-03-2013, 08:45 PM
yankee-flyer yankee-flyer is offline
 
Join Date: Jun 2009
Location: Dayton, OH
Posts: 838
Default Me too, also

I moved the cooler forward also and solved my high oil temp problems. It should be MUCH easier to do this during the build than later. Search for Cowl Duct Modification-- good photos and a source for drawings that work.

Wayne 120241/143WM (205 hours)
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  #5  
Old 10-04-2013, 09:24 AM
MacPara's Avatar
MacPara MacPara is offline
 
Join Date: Apr 2010
Location: Tucson, AZ
Posts: 461
Default

Quote:
Originally Posted by 08FATBOY View Post
I have less than a 1/2" of space between the oil cooler and muffler. I haven't epoxied the duct to lower cowl. Anyone have an average measurement for this.
I have seen a photo of the duct cut out. Does anyone have better photos and possibly instructions or dimension to do the job? Need help as fiberglass repair is not one of my strong points. Thanks for your help!

Rod
Rod,

living in Tucson, AZ I did not wait to discover cooling problems and I modified the oil cooler position during the build:
http://torstensrv-12.blogspot.com/20...ling-duct.html

This gave me a good enough clearance to the muffler when the oil cooler was mounted:

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RV-12: #120374, ELSA, N128TL flying since Nov 28, 2013 (Phase 1 completed 1/26/14)
SkyView, Light Package, ADSB
http://torstensrv-12.blogspot.com/
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  #6  
Old 10-04-2013, 09:27 AM
Dave12 Dave12 is offline
 
Join Date: Oct 2010
Location: Elkton, Md.
Posts: 1,652
Default

Everything you ever wanted to know, but was afraid to ask about the cowl mod.
http://www.vansairforce.com/communit...otax+likes+hot
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Wag Aero Sport Trainer built,sold and wrecked
N588DF RV12 #336 built, sold and alive and well in New York
N73DF RV12 #244 built, sold and alive and well in Florida
N91 RV RV9 I wish I could say I built this one! Mark Santoleri hit the ball out of the park on this gem.
Currently restoring a 1978 Citabria GCBC
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  #7  
Old 10-04-2013, 09:45 AM
roger lee roger lee is offline
 
Join Date: Sep 2013
Location: Tucson, AZ
Posts: 322
Default

Hi Macpara,

I'm in Tucson also at Ryan Airfield hangar C22 on the east side of Ryan. I have an SLSA RV12 that will be here Wed. morning (Oct.10th).
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Roger Lee
Tucson, AZ
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  #8  
Old 10-04-2013, 10:50 AM
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MacPara MacPara is offline
 
Join Date: Apr 2010
Location: Tucson, AZ
Posts: 461
Default

Hi Roger,

you helped me sell my RANS S-12S in 7/2011 doing the Rotax pre-sale inspection on it. Good to see you are joining the RV-12 crowd :-). I'll be coming by for a visit when mine is certified or I'll step by after work during the week, as I'm working close to TUS and RYN is not really much of a detour on my way home. I'm hangared at AVQ now.
I am curious what temps you will see with the SLSA but it's cooling down now pretty quickly, so we might have to see what it does next summer.
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RV-12: #120374, ELSA, N128TL flying since Nov 28, 2013 (Phase 1 completed 1/26/14)
SkyView, Light Package, ADSB
http://torstensrv-12.blogspot.com/
APRS Track
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  #9  
Old 10-04-2013, 01:41 PM
RFSchaller RFSchaller is offline
 
Join Date: Oct 2010
Location: Phoenix, AZ
Posts: 2,820
Default

I live in the Phoenix area, and did not modify the oil cooler spacing. In summer I end up climbing in about 2000 FT steps pausing to cool down a bit at4800 RPM.
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  #10  
Old 10-04-2013, 07:27 PM
roger lee roger lee is offline
 
Join Date: Sep 2013
Location: Tucson, AZ
Posts: 322
Default Unwanted heat.

None of us here at Ryan airfield are having any over heat issues and we see some hot OAT's in the summer, but we are all propped regardless of the prop type to 5600-5650 rpm at WOT flat and level. That said some people with their aircraft have air flow issues across the coolers and or engine.


Prop pitch can play a huge part in the engine cooling. Over pitching causes excess heat and stresses the engine. In the older Rotax crankcases (pre mid 2006) setting a prop pitch to only see about 5200 rpm at WOT (wide open throttle) was cracking some cases, hence the later SB from Rotax. The cases that came after that are different, but you still shouldn't over pitch. It hurts climb, cruise, fuel economy and causes unwanted heat. A sweet spot for many LSA with the 912ULS or UL is right around 5600-5650 rpm for a WOT flat and level pitch setting. This is a good balance since we don't have an in flight adjustable prop. That of course would be the best. Setting this at your average flight altitude makes a difference too. As an example if you live down at sea level and never get more than 1000' AGL then set it for that altitude. If you fly at 8000' most of the time set it for that average altitude. We just have to find that balance to make us and the engine happy at the same time. people always ask what the static should be. Static is really only good to use when you have an unknown prop and setting. You will always need to fly it to double check it and fine tune it after your first setting. Plus if you go from 5200 rpm WOT to 5650 rpm WOT you'll think someone just turboed your engine. There is a difference. I have change at least 100 LSA prop pitchs over the last several years and not a single person ever wanted to go back to something like 5200 rpm WOT.
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Tucson, AZ

Last edited by roger lee : 10-04-2013 at 07:29 PM.
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