[bjdecker]

I've seen a few RV-7's and -8's with IO-360-A's and M1 engines where the builder didn't bend the 3rd baffle flange on the #3 cylinder baffle/right rear baffle wall. This creates a gap between the cylinder base, case, and rear baffle adjacent to the dipstick. Attached excerpt from OP-4 -- area circled in BLUE.



If you're chasing higher-than-you'd-like CHT's, check this area. If it's open/not bent, consider plugging the hole with a piece of fiberglass impregnated with Hi-temp Silicone sealant or similar.

 

[planenutz]

Yes - 100% something to look out for. After getting my machine flying I was chasing CHT differentials and when I went looking at the finer details of the baffling I noticed this tab had not been bent. Somebody else had helped install the baffles during installation however I never noticed so it was clearly my own fault and its very easy to miss.

The longterm downside? Additional airflow over that specific area of the cyclinder could cause a cool spot that accelerates internal wear in that localised area.

Good post, Brian.

 

[DanH]

+1. Tab at the base of #4 also.