Hi All,
New to the forum as a friend and I just partnered in an RV-6 a few months ago. (What a great plane!)
We installed a 4-channel engine monitor on our Superior O-360, and noticed that CHTs ran quite hot. We regularly saw average temps at or above 425, sometimes past 450. Also our rear cylinders ran about ~50deg hotter than the front.
After reading many of the posts here, we completely went through our baffles and sealed any leaks we could find (there were several). We also added some aluminum ramps(?) to the front cylinders to balance the temps.
We're now seeing very uniform temps around 400 deg on all cylinders. This latest data point was at 86F, 3000' MSL, 23", 2300rpm, ~8.5gph, 152kts TAS.
But that still seems too hot. So any suggestions on our next step? Options we have are:
(1) Adjust the timing -- we're at 25 degrees now with higher compression 9:1 cylinders. (We read that moving that closer to 20deg could help)
(2) Open up our cowl exit to get more airflow
(3) Fine tune the baffles more. The items we haven't done are (a) blocking the gap between the cylinders and (b) filing the flashing between the fins by the plugs (we inspected this area and actually have minimal flashing here, but of course even small protrusions into the airflow could have a large effect).
Any suggestions on how much the timing might be an issue? (i.e., we don't want to cut open our cowl exit if the timing is the dominant cause of high temps).
Any suggestions on what measurements we can perform (cowl pressures, etc) that could help point to the best fix?
Thanks!
James
New to the forum as a friend and I just partnered in an RV-6 a few months ago. (What a great plane!)
We installed a 4-channel engine monitor on our Superior O-360, and noticed that CHTs ran quite hot. We regularly saw average temps at or above 425, sometimes past 450. Also our rear cylinders ran about ~50deg hotter than the front.
After reading many of the posts here, we completely went through our baffles and sealed any leaks we could find (there were several). We also added some aluminum ramps(?) to the front cylinders to balance the temps.
We're now seeing very uniform temps around 400 deg on all cylinders. This latest data point was at 86F, 3000' MSL, 23", 2300rpm, ~8.5gph, 152kts TAS.
But that still seems too hot. So any suggestions on our next step? Options we have are:
(1) Adjust the timing -- we're at 25 degrees now with higher compression 9:1 cylinders. (We read that moving that closer to 20deg could help)
(2) Open up our cowl exit to get more airflow
(3) Fine tune the baffles more. The items we haven't done are (a) blocking the gap between the cylinders and (b) filing the flashing between the fins by the plugs (we inspected this area and actually have minimal flashing here, but of course even small protrusions into the airflow could have a large effect).
Any suggestions on how much the timing might be an issue? (i.e., we don't want to cut open our cowl exit if the timing is the dominant cause of high temps).
Any suggestions on what measurements we can perform (cowl pressures, etc) that could help point to the best fix?
Thanks!
James