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The AeroVee engine that I recently purchased was configured for an Onex so it is setup for a top mounted oil cooler. I've read in the SonexTalk archives that for a Sonex / Waiex, this was not recommended due to interference with the cowling....I can easily overcome the cowling issue.

I'm curious if anyone in this forum is using a top mounted oil cooler...if so, what are your recommendations. Here are some of my thoughts about the pros / cons:

Pros:
- Should help with the cooling by eliminating a high pressure air source under the cylinders
- Eliminates the need for a second cowl opening (reducing cooling drag)

Cons:
- Potential cowl interference
- Is dumping hot air on top of the rear cylinders worse than pro # 1 above?
- The hot air from the oil cooler may be acting as Carb Heat for the AeroInjector?

Please feel free to share your thoughts...

Hi Frank,

If I had the option I would switch to a top mounted oil cooler simply to reduce the number of oil lines that run from the oil pump to the cooler. Plus, like you said, it may work a little better.

Unfortunately, I'm not sure how big of a cowling blister you would need to graft onto the cowling in order to make clearance for the cooler. Also, you will probably still need to open a spot in the cowling to allow air to pass over the bottom of the engine. The manual says that is an important part of cooling.

The good news is you should be able to make your engine "Sonex stock" by changing to the Sonex style oil pump. You may be able to call Kerry at Sonex and ask about the factory Waiex; I think they switched to the upper cooler when they added the turbo system. They may be able to help!