The International Cessna 170 Association

Noticed these gaps between rear parts of engine cowling. I would think there should be baffling, both sides same. I understood the better seal, the greater the cooling efficacy across more of the cylinders.(more air =more cooling). I'm in charleston sc so it gets really hot! What kind of baffle do most use, if anything? Anyone have a picture of how this should appear? I am really enjoying the plane I took a news reporter up yesterday to take video for a local interest story - with doors- perhaps with shoulder harnesses -sans door. Thanks again, Tim

Looks like you're missing the rub strips. Have you looked at the Illustrated Parts Catalog?

All of those pin holes are from staples which was used to hold a black rubber impregnated cloth rapped around a bulb like this material: This is from http://www.brownaircraft.com in read. The bulb comes in different diameters and I'd think you want 1/2". I did find it in black someplace but can't find it now. You use safety wire to stitch it on through the staple holes. Unless of course you have Cessna's monster stapler.

Unless you’re an originally nut, you can also use silicone rubber baffle seals.

There is an important difference in the New2cessna's baffling and Miles baffling. Mile's later 170 uses the cowl as part of the pressure box and New2cessna has the early baffle pressure box.

Though I'm sure it's been used, folding the flat springy silicone baffle over to close the early baffle, may be nearly an impossible task. On the other hand, when installed correctly, the P or bulb of the original style and that I showed, is placed so just the bulb sits on the 90° inside intersection of the back and top baffles, sealing it. Nearly anything between the back baffle and the top, stops the baffling from being closed.

Bruce Fenstermacher wrote: ... I did find it in black someplace but can't find it now. ...

The silicone coated tadpole tape you pictured is available in black or red here. Reviews indicate this matches the original seal.I’m considering using ”cowlsaver” baffle seal material from McFarlane. With teflon on one side it’s pretty slick stuff.McFarlane also makes a scoring tool to increase the flexibility of silicone baffling.

I have new Airforms baffles that I installed about a year and a half ago on my 52 B model (with plenum baffles like yours) and they have black silicone P seals like the ones sold by Spruce here: https://www.aircraftspruce.com/catalog/ ... ckSeal.php.
The round part is hollow and about 3/4"-7/8" OD, and the tail is about 1/2" long. They work well because the hollow portion is flexible enough and of sufficient diameter to conform to varying gap widths.

The black stuff Gary pictured in the middle is what I used. I couldn't find it when I was looking for an example

http://www.brownaircraft.com/product-p/vs-6491.htm

Can anyone with a 170B speak to the use of RTV between the valve covers and the engine baffles? I’m replacing all the baffles in my airplane with the Airforms kit. The baffles I removed had the RTV, but most of the pictures I have found on this site do not have the RTV.

And thank you to Miles for posting a great example of a beautiful firewall-forward installation!

Ryan, with the baffles and silicone seals from Airforms, I haven’t found it necessary to use RTV between the baffles and valve covers. Even on the warmest days in a climb, oil temps top out around 210, and CHTs around 390. That said, every installation seems to be different, so YMMV.

Thanks Miles. I’ll fly it as-is and reevaluate down the road if necessary.

Well, I had a tube of RTV and some spare time, so I went ahead and sealed the valve covers. #2 and 4 show some signs of excessive heat, and operating in FL has me concerned about cooling.