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I had a nasty, albeit small, leak on the pump side of the factory oil cooler that developed last year. I thought it was the o-ring, but after changing it no change - still a post drive drip developed on the garage floor. After doing some more reading, it turns out the factory oil cooler could develop a few issues which either necessitate replacement (have you seen the prices on these things?!) or repair (not easy on the thin aluminum cooler loop). After inspecting and measuring the ends on mine, it looks like my leak was caused by some scoring and deformation of the cooler end fitting which means it would never fully seal.
Lots of options out there, with budget in mind and a desire to not tap the holes in the transaxle case, I decided to go with custom fittings and a cooler modeled after the one available from a UK based supplier. Information on making custom oil hoses with AN fittings are readily available, as are aftermarket stacked plate oil coolers in a variety of sizes. I procured an imported mini lathe (again, BUDGET lol) and turned these out of a pair of evil energy AN-8 straight couplers:
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The recess for the mounting flange is 14mm, made with a 2mm parting tool. The thicker part of the fitting that seats in the o-ring is 0.625" for a tightish fit while testing on my transaxle.
After cobbling together some mounting brackets, here's how it ended up:
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I think the cooler will get enough airflow there to be at least as efficient as the outgoing stock cooler loop. I'll do some testing as the temps here (midwest, near Chicago) go up over the coming weeks/month. I may also try to make a skid plate or something else to help protect the cooler and lines as they do sit a little low and I'm concerned about picking up rocks and other road debris.
In the meantime, after a few test drives, I've observed NO LEAKS and now have more easily replaceable parts making this project a success in my eyes.
You've created a nice arrangement for your cooler. Nice work!
I did notice both the entry and exit ports on your cooler are on the bottom. This won't allow the cooler to fill with fluid and therefore greatly reduce the cooler's efficiency. With both ports on the bottom, fluid will travel horizontally toward the exit port through only the lower part of the cooler. Making sure the cooler will fill requires the entry and exit be at the top, or the entry at the bottom and exit at the top.
Case in point: I had a team bring me an RSR because they couldn't control oil temperature even though they had THREE oil coolers. The issue was the way they were plumbed - none of the coolers were filling with oil. Once the plumbing was corrected the oil stayed cool with ONE cooler.
MM
This is great info and makes me glad to have posted it. Time to reconsider mounting options, which is good anyway because I wasn't super happy with the fittings being on the bottom - they're really exposed to potential damage.
Went back to the drawing board based on the critique above and now it looks like this:
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I'm much happier knowing the cooler is now oriented correctly (didn't know that was a thing until this post!), the hoses and fittings are tucked up higher out of the way, and the extra bracing makes me feel better about this setup too. One test drive down, still no leaks. I'll likely add some kind of duct or shield to the cooler body as well to help protect it from road debris and might make something a bit less cobbled together for mounting if I decide to keep this around.
