David-aviator
Well Known Member
#4 CHT has always been 15-20F hotter than 1-2-3. Yesterday, with the OAT at 55, the air flow to the oil cooler was closed and after 5 minutes #4
CHT was the same as #1, 15-20F cooler.
So if balancing CHT's is on your agenda, do not overlook the affect of air going through the oil cooler, that stolen air is not cooling the cylinder.
My cooler is remote with a 4" SCAT tube providing air from the aft baffle at #4 with a butter fly shut off valve. The installation idea came from the RV-10 as I was obsessed with having adequate cooling after several years doing battle with cooling issues and the Subby H6.
For those thinking about departing from the standard Van's oil cooler arrangement, good friend Roger Mell is working on baffle install and it was determined yesterday a remote mount on his -7 won't work as it does with my -7A due to the engine mount differences. We also discovered the double pass SW 8432R cooler will not fit the aft baffle, the cooler is 1" too wide. So he arranged a swap for the 8406 which is the same size as the Van's cooler, which probably is a Niagra.
This not to suggest the standard Van's set up is less than necessary, there are plenty of guys flying with it and all is well. But there also are some who are at war with the issue. I decided to go with SW because they are hands down a better cooler. Yea, they cost more but this is one case where you get what you pay for. The Subby H6 had Niagra's and that may have been half the cooling problem. With the Lycoming, I am pleased to say there are no oil cooling issues at all. If anything, it runs too cool.
(Very nice day to fly yesterday morning with still air. But it looks like all that will change in the next 24 hours with a cut off low approaching from California.)
CHT was the same as #1, 15-20F cooler.
So if balancing CHT's is on your agenda, do not overlook the affect of air going through the oil cooler, that stolen air is not cooling the cylinder.
My cooler is remote with a 4" SCAT tube providing air from the aft baffle at #4 with a butter fly shut off valve. The installation idea came from the RV-10 as I was obsessed with having adequate cooling after several years doing battle with cooling issues and the Subby H6.
For those thinking about departing from the standard Van's oil cooler arrangement, good friend Roger Mell is working on baffle install and it was determined yesterday a remote mount on his -7 won't work as it does with my -7A due to the engine mount differences. We also discovered the double pass SW 8432R cooler will not fit the aft baffle, the cooler is 1" too wide. So he arranged a swap for the 8406 which is the same size as the Van's cooler, which probably is a Niagra.
This not to suggest the standard Van's set up is less than necessary, there are plenty of guys flying with it and all is well. But there also are some who are at war with the issue. I decided to go with SW because they are hands down a better cooler. Yea, they cost more but this is one case where you get what you pay for. The Subby H6 had Niagra's and that may have been half the cooling problem. With the Lycoming, I am pleased to say there are no oil cooling issues at all. If anything, it runs too cool.
(Very nice day to fly yesterday morning with still air. But it looks like all that will change in the next 24 hours with a cut off low approaching from California.)