baffle to cowl gap distance

[Scott Will]

Started trimming my baffles and thought things were going swimmingly. Got the contour right on by using a huge washer and marker. I was going for 3/8 but ended up much bigger than that when I put the cowl on again. I suspect, something was off when I did the inital marking.

That being said - what kind of gap can you live with? is 1/2 or 5/8 OK? Will the airseal material be OK for that distance?

If not, I guess I can make a little doubler plate that adds some height to it.

Just curious. Want to get these things done!!!!!!!!

Thanks for the help!

 

[Bob Axsom]

The gap should be fine

Don't be skimpy with the seal height and you should be fine. I ended up having to trim off the front corners of the side pieces (metal) because they were making contact with the cowl. Caught it during the annual.

Bob Axsom

 

[Kevin Horton]

I ended up having to trim off the front corners of the side pieces (metal) because they were making contact with the cowl.

Bob,

How much clearance did you have at the front corners? How much did you increase the clearance to when you did the last trimming?

 

[Bob Axsom]

I used a 3/8" gap

I used a 3/8" gap all around. When I pulled the cowl off for the annual I saw the slight markings of metal contact on the underside of the upper cowl at the extreme front end of the baffle side plates. I just took my tin snips and cut around a 1/2" radius where the corners had been and deburred it without removing the seal. The marking was light enough that I believe the problem is eliminated but I would have to paint the surface and and look for markings after flight to confirm that.

Bob Axsom

 

[fodrv7]

Rocking engines

As the engine rocks (particularly on start up and shut down) the greatest movement is on the outside edges.
Besides the Inlet baffles, it pays to have a lttile more clearance on the outer edges of the rear baffles, especially around the oil cooler.
Mine are nearer 1/2" and the CHTs and Oil temps are if anything a little low. 220?C and 80?C respectively with OAT around 20?C
Pete.