I just noticed the oil plate used AN fittings instead of the shitty leaky NPT ones I have and was wondering where I could find one for a miata. All the ones I've ever found are either NPT or discontinued years ago.
For low pressure and stuff like water, I think NPT stuff is just fine. My brewing rig is all 1/2 NPT with no issues.
For high pressure oil or fuel, I think it's very much a roll of the dice. For example, my 1/2 NPT oil thermostat doesn't leak, and the oil cooler itself doesn't leak, but I had to redo those connections 2-3 times each and seal the threads with tons of gasket maker to get the leaks to stop. And I'm not entirely sure the oil cooler itself is perfectly sealed. The plate that goes in place of the oil filter still leaks despite probably half a dozen attempts.
I'm afraid that after I upgrade the oil pump I'm going to have 70psi going through those lines all the time... which means I'm going to leave a trail of oil everywhere.
Last edited by AlwaysBroken; 11-22-2015 at 08:33 PM.
I didn't know such a thing existed when I put together my build. To be honest, I didn't know about until you just mentioned it. I think integrating the thermostat into the sandwich plate is a great idea so I probably would have gone this route if I had known about it.
That being said, I've got a mostly non-leaky setup that just needs about 80 bucks in parts (including all the AN hose ends, fittings, etc) to be perfect.
I am by no means a professional though. We used AN fittings in the military for our Jets without any thread tape or dope, but we almost always had something leaky. Hell, if those things weren't leaking something was wrong.
All I have to say, is if you do go the AN route, buy the highest quality you can afford. The cheap ones are hit an miss junk and leak like crazy. I have a few that all have a different angle cut on the taper, so they'll never seal.
The 3rd gen Miatas have a known failure point with the cast-aluminum oil plate cracking and then letting go of your oil filter, typically while you're applying some track abuse. It's worse when an oil sandwich plate is used for an external oil cooler because of the additional stress of the hanging lines.
Just ordered one of the pictured units for my NC build to avoid this scenario.