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  #11  
Old 10-06-2012, 06:25 PM
vgb vgb is offline
 
Join Date: Aug 2007
Location: northern Cal
Posts: 111
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Thanks for the help. I will ream the jet a little at a time. What number of ream can I expect to go to? I'm going to fly and watch the instruments closely.
I checked timing several times, so can't be that.
When someone solves a problem like this it would be good if they posted what solved the it.
I will post when I get this figured out.
Vern
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  #12  
Old 10-06-2012, 11:14 PM
N427EF N427EF is offline
 
Join Date: Oct 2005
Posts: 1,516
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Don't get too hasty boring out your carb jet.
Considering the fact that you are also running hot in cruise, where you are able to run full rich without affecting your temps, a lean mixture is not likely where you'll find the blame for your hot temps.
What is your compression ratio and where do you have your magneto set?
Do you have some pictures for us to look at, engine installation,upper and lower cooling and baffling installation, anything unusual?
If it's not fuel or ignition related it has to be something pretty unusual to generate temperatures like the ones you have.
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  #13  
Old 10-07-2012, 07:17 AM
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DanH DanH is offline
 
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Location: 08A
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Quote:
Originally Posted by N427EF View Post
Don't get too hasty boring out your carb jet.
Agree. Big picture:

Sometimes it "cures" the problem, but consider engine fundamentals. A very rich mixture is just an expensive way to reduce power. Rated power, the horsepower you paid good money to buy, is found at best power mixture, 100 to 150 ROP for an NA Lycoming. That mixture also results in the highest CHT and oil temp, hardly a surprise.

Assume reasonable OAT, correct ignition timing, and normal combustion (no detonation or preignition). Cylinder or oil temperature outside limits at full power indicates a cooling design problem, or a cooling installation problem, or both. A power reduction, however accomplished, is just a crutch.
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  #14  
Old 10-08-2012, 08:20 AM
N427EF N427EF is offline
 
Join Date: Oct 2005
Posts: 1,516
Default Excellent example

Here is an excellent example of what affects temperature in a big way with a small adjustment.
http://www.vansairforce.com/communit...ad.php?t=91788
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RV-10 Flyer 600 plus hours
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  #15  
Old 10-08-2012, 10:24 AM
vgb vgb is offline
 
Join Date: Aug 2007
Location: northern Cal
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All good information. I'm going to check everything all over again.
When I changed oil coolers it made a lot of difference. If I get cht down I think oil temps would drop to.

Vern
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  #16  
Old 10-08-2012, 10:36 AM
vgb vgb is offline
 
Join Date: Aug 2007
Location: northern Cal
Posts: 111
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All good information. I'm going to check everything all over again.
When I changed oil coolers it made a lot of difference. If I get cht down I think oil temps would drop to.

Vern
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  #17  
Old 10-08-2012, 01:05 PM
rvsxer rvsxer is offline
 
Join Date: May 2007
Location: Inver Grove Hgts, MN
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Mr. Horton is absolutely correct about the carb mod. The only reason I even mentioned it was because the takeoff fuel flow seemed a little low. I had the richer profile kit put in my carb only after it was firmly established I was at or lean of peak at full rich and not even able to richen to "best power". As I remember my temps were not the biggest problem. Check all the other items mentioned in this thread first then only give the carb a look if you can't get that 100-150 degree rich-of-peak in flight.
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