Somebody did AN fittings on their heater core. One of the Ryan's maybe?

Blue car. Atlanta maybe? Was totalled and he fixed it?

 

Another option is to sweat some length of copper pipe and do a flare nut/sleeve style fitting.

 

**** YEAH STEAMPUNK STYLEEE

 

OK I win at internetting.

NB heater core is aluminum. Weld fittings on.

@bbundy did it here: https://www.miataturbo.net/general-m...e-54171/page2/

Now I'm regretting throwing away that NB heater core last week.

 

lol, so many options. I will stick with NA core for now and see what I can do

 

I might be able to get you a NB2 heater core and bring it up this weekend.

 

Per that thread that was linked a few posts up, it appears the heater cores are only interchangeable if the entire housing thingy goes along with it, is that not the case?

 

Orly? if you do come up this weekend, you should talk Soviet into coming up to the Frederick autox for some with me.

 

I have no clue, I just believe I have access to a NB2 heater core in a friends parts car.

Ohh where at in Fredrick is it? I will be up Pasadena Saturday morning picking up more NB mid pipes for my turbo setup. I might be able to swing by and say hey and give you stickers and **** or something.

 

Pasadena, MD? If so you should stop by my place and say hi, Pasadena is right next door (literally 10 minutes away depending where at)

 

Can I have 4th hanger and A/C switch plug?

 

Did the AC switch plug I sent you ever show?

 

sadly, while similar, it doesn't fit :/

 

That's odd. I believe it was off of an NB1 of that helps your search.

 

http://www.capitaldrivingclub.com/schedule.php
Join us for the fun and drag Soviet out. I haven't seen him in forever.
If you are by your self, I should still be easy to spot. Miata is back to green now and I will email you my cell #.

 

This is what i'm referring to. It's brass and you would need to drill out the threaded portion to slip over the heater pipe. I can't find anything that is sweat by flare.

Larsen Supply 3/8 Female x 1/2M Flare Adapter 17-5833

3/8" pipe has a nominal outside dia of .675" so that means if you got rid of all the threads you would have .050" of diameter slip fit which I think is a bit much. A 1/2" fitting for brazing has ID between .627" and .631" and 1/2" tubing OD is .622" to .626" so max to min you only need .001" clearance for brazing. So I'd say a 5/8 drill bit should be good to go with a little wobble drill if needed. Or try and get a 16mm drill bit? Or don't compress the 17mm heater nipple and get a 43/64" drill bit?

In any case I think this fits your need of being cheap, tidy, and failproof as when properly done, a brazed connection will never fail and when properly tightened, flared connections never come undone or leak. And the fitting has the added bonus of having a hex head that you can use to properly tighten the AN fitting with.

There are two things I'm uncertain of: is there any issue with brass to aluminum touching and the flare angle of these particular fittings. The flare tool you bought is what is commonly used to make flares for gas fittings which is what this fitting would be used for. Some research says it is JIC/AN which is 37*. The ASE flare is 45*. But I just can't say for sure as the fitting doesn't have a spec.

 

I welded steel -10 bungs to some scrap steel tubing that fit the inset on them. Slid those steel tubes into the heater core tubes and brazed them. Both tubes pressure tested OK to 20psi and have not leaked with maybe 10 hours on them.


Used some ford/chevy v8 valve cover breather grommets for the firewall heater tubes. They make for a very snug and sturdy fit compared to the stock pieces.

 

Looks awesome.
Can you dumb down the brazing part for me? If I want to attach stainless fittings that slide onto brass tube, how can I do it? I read about brazing, silver brazing, soldering, and they are all different temperature. I've only sweated copper pipe in the past.

 

I use Harris Safety-Silv 56% and their Stay-Silv flux. I take the same approach I do to sweating copper pipes. I head the heavy stuff (bungs) and the thin stuff heats by default. Then do test "dabs" with your rod/wire. When the temp is good it will flow to the joint. I'm by no means an expert, just serious time on youtube watching brazing. I've managed to do these heater core lines, a high pressure AC line with the same metals and aluminum AC lines. No leaks on any of them. Key advice: practice first. I brazed a brass tube to a big steel nut first fwiw.

I used the steel tubes because the brass heater core tubes were too large to fit the inset/recess in the AN fittings. Could have just as easily used a lathe to open that up- if I had one. You just need to be discrete with heat around the heater core tubes given their lack of wall thickness.

 

Installed SadFab coil bracket, removed like 10% of the car's total rust.

Wires are less than ideal length but fits fine