Data: RV7A with Aerosport IO-375 and low compression, oil squirters installed. Oil and CHTs will run up over 220F and 400F if I let them but I do not, via running lean of peak. I cannot run at best power mixture very long without busting though those temp limits, but I can cruise all day, as long as I keep it well LOP, burning about 7.5GPH. Also have EZ Cool cowl flaps, it will go too hot even with them open. Baffle seals are not perfect but they seal well and all other leaking areas have been sealed, washer behind number 3 etc. I have measured pressure delta above and below engine, and at the oil cooler and the numbers are good. I have dual Pmags, pulling timing way back makes no difference. Vernatherm is gone and oil plunger installed so all oil goes to the cooler unless oil pressure goes above about 100 PSI. Engine now at about 95 hours, oil consumption normal.
In my quest for lowering my cylinder head and oil temperatures I finally got around to measuring the gaps in the cylinder head baffle wraps. I cannot explain why I waited so long to do this. A conversation at the Reno races got me to check this when I got home. What I found surprises me and I wonder if the following dimensions are possibly by design?
To clarify, these are the gaps at the cylinder heads, not the cylinders themselves.
My gaps.
Cyl. (1) 1-1/2" Cyl. (2) 2-5/8" Cyl. (3) 2-3/4" Cyl.(4) 2"
That seems like a lot of variation. The wraps are held nice and snug to the cylinder fins so that is not the issue. I made my own tapered cylinder baffle wraps, but the wraps for the heads are stock from Van's kit.
Anybody know what the gaps that let the cooling air escape from under the heads should be?
Are these gap dimensions normal?
Maybe this is finally the "smoking gun" I have been looking for that might help explain my persistent high oil and CHT temps.
Randall in Sedona
In my quest for lowering my cylinder head and oil temperatures I finally got around to measuring the gaps in the cylinder head baffle wraps. I cannot explain why I waited so long to do this. A conversation at the Reno races got me to check this when I got home. What I found surprises me and I wonder if the following dimensions are possibly by design?
To clarify, these are the gaps at the cylinder heads, not the cylinders themselves.
My gaps.
Cyl. (1) 1-1/2" Cyl. (2) 2-5/8" Cyl. (3) 2-3/4" Cyl.(4) 2"
That seems like a lot of variation. The wraps are held nice and snug to the cylinder fins so that is not the issue. I made my own tapered cylinder baffle wraps, but the wraps for the heads are stock from Van's kit.
Anybody know what the gaps that let the cooling air escape from under the heads should be?
Are these gap dimensions normal?
Maybe this is finally the "smoking gun" I have been looking for that might help explain my persistent high oil and CHT temps.
Randall in Sedona