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#2 CHT higher than the others

Bsquared

Bsquared

Well Known Member
Has anyone removed the air dam in front of #2 entirely? I have it trimmed down to almost nothing and #2 still runs 30-40 degrees higher than the others in cruise. Looking at other RV-14 posts it seems that #2 is usually the hottest. Has anyone reworked the baffles or cowl ramp to balance the temps out?
 
My #2 is 20 deg hotter than #1 which is 10 deg hotter than 3/4. Max temp summer climbing from SL in Louisiana was 370. Cruise is typically 335/315/305/305 at 10000. Taking the dams off the front of the cylinders didn’t make it much better but I did leave them both at about half height because if I don’t the bugs collect. I think that if I could put a little bypass thru the snorkel on 2 it would make a big difference. My arrow had a 5/8 tube that was directed into the lower half of 2. It was an io360. Any tube like that on the 14A would have to pass thru the snorkel and would not be easy to open up to the airstream forward.

The gap between the baffling and the front of 2 is very narrow. I’ve also considered putting a deflection ridge up on the cowling to push some air down to the back side of cylinder 2 but everything is within tolerances so I’ve not tried to perfect the situation.
 
Air dams

I removed completely my air dam in front of 2 and cut the one in front of one down halfway. Could probably cut a little more later. Bugs not an issue. Help equalize a little. Instead of 2 and 4 being 30 degrees delta now 15.
 
Maybe...

I'll catch flak for saying this, but a 30°-40°F between heads is really not a problem.

I suppose if you cannot manage your OCD and *must* have perfectly matched temps, start looking at changes on the bottom side of the cylinders -- e.g. is there a little too much RTV on the cylinder baffle wraps? is there air leakage along the sides of the wraps? How about the space between the wraps along the exits -- is it the same from cylinder to cylinder?
 
bjdecker said:
I'll catch flak for saying this, but a 30°-40°F between heads is really not a problem.

I suppose if you cannot manage your OCD and *must* have perfectly matched temps, start looking at changes on the bottom side of the cylinders -- e.g. is there a little too much RTV on the cylinder baffle wraps? is there air leakage along the sides of the wraps? How about the space between the wraps along the exits -- is it the same from cylinder to cylinder?
Click to expand...

99% of RV builders have OCD.
 
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