Thoughts on Warner oil coolers?

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bbarrett
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Thoughts on Warner oil coolers?

Post by bbarrett »

What are Warner powered folks using for oil coolers? When I bought N28525, it had what looks like an oil cooler for a 4 cylinder Lycoming installed similarly to Charlie Bell's drawing in the club DVDs. My first annual, we removed it because my IA and all the mechanics in the area with Warner 165 experience said that it shouldn't need an oil cooler. And it worked great, right up until last August when I was flying in 90 degree weather and I was seeing oil temps right at (or a bit above) red line. The blast tube at the oil cooler doesn't seem to quite get the job done.

The part that I don't like is the lack of a thermostat of any sort in the Lycoming-style oil cooler. It's better than nothing and what I'll reinstall this annual barring other ideas. I haven't found the Harrison 8528147 Charlie calls out, was curious if others had success with other options.
Dave Hadfield
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Joined: Mon Dec 16, 2019 3:35 pm

Re: Thoughts on Warner oil coolers?

Post by Dave Hadfield »

I have a Warner 185 installed in my F-24. This was done in the late 1940s. There is an oil cooler installed, but there is no real data on where it came from.

It's on the firewall. A SCAT hose links the aft end of the blast tube to the cooler inlet shroud, then out through a port in the left aft cowling.

My oil temps with it are about 85C on a very hot summer day -- more often 75-80C. But you're right, there is no thermostat and it takes quite a while to get there. Usually I climb up high enough to get cooler air before the oil heats up that much. However that strategy is no good during multiple hops.

I also put a glue-on heat pad on the oil tank. I like to start with oil above 20C, which, in Canada, is more often the problem.

I have a baffle I bolt onto the blast-tube entrance for when flying under 10C.
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