You dont really want that, it'll never heat up if the car ever sees street time.

All you need is a 90* bend with ~12" off one end. I have mind split as you can see for the Hester return and coolant sensor.

I would keep the heater core, even for a track car. I don't know man, its certainly been useful especially on cold mornings with frost.

I understand the arguments about the heater core. This is for a dedicated track car that won't run on the street at all - trailered to track events. I want the cooling benefits of 100% of the coolant going through the radiator every pass but want to keep the option of blowing hot air on the windshield when it rains. In the past the heater has also served as emergency cooling but I hope that won't be necessary with the other preparations being taken.

how are you going to get hot air if you delete the heater core?

I'm not deleting the heater. I want to route the return to the hot side of the radiator.

ohhh, gotcha, I was thinking most people just leave it hooked up as is, but I guess not.

In the stock configuration, hot water from the heater core mixes with the cool water from the lower radiator hose. It would seem there are some improvements to be had on the total thermal capacity of the system if the water leaving the heater core passed through the radiator. I appreciate this would cause a street car to warm up very slowly since a bunch of coolant would be bypassing the thermostat but for a track car, it should help it stay cooler. It would not behave much differently than a gutted thermostat but would cool more overall. My plan would be to leave a thermostat in place to help stabilize the temperatures from being too cold. This would all be on the traditional BEGI reroute with the proper head gasket, etc.

You guys hurry up and figure all this out and post exactly how you did it with a list of parts and part numbers and a nice step by step pictorial "how to". My motor is going back in the car in a week or two so I'm running out of time! Just kidding :). A little.

Okay, freeze plug worked for plugging mixing manifold

Dorman 550-010 7/8"/22.17mm

There's about fifty different configurations. It all depends if you still want a heater core, if you want it to work in anything but race conditions, what your cooling setup is, etc.

The "easiest" is currently:

1. water neck
a. junk yard cheap
b. BEGI for a little more
c. cut down the coolant sensor and weld a cap over the stock 1.6 unit.
2. Spacer
a. build your own
b. BEGI for $90
c. M-tuned housing $180
3. hose
a. GM hose for $20
b. build your own with a bit of straight pipe and a couple bends $???
4. block off plate
a. BEGI $25
b. freezer plug $1
c. fab your own cover $free

the EASIEST is a $120 order from BEGI of a spacer and water neck, and $25 order at NAPA of the GM hose and freeze plug.


After that, you need to decide where the heater core return goes. If you're only racing, put it in the upper radiator hose. If it's still street driven, put it in the lower radiator hose. If you're deleting the heater core, you need make sure there's some feed to the water pump until the thermostat opens.

Thanks, Curly, that helps a lot. Simplest explanation I've seen yet.

You're welcome. There's of course some fudge factor, as technically the EASIEST easy method is shelling out $330 to FM or another vendor for m-tuned's reroute, although this thread was a little more oriented towards the DIY method. It's a push in the right direction though.

As you can read over in my build thread, my car has just become a track only car. What are the benefits of removing the heater core? Is it just weight? Does leaving the heater core affect cooling efficiency? The car came with a PWR radiator when I bought it. Maybe removing the heater core is something I can do down the line when I put in a cage and have the dash out anyway.

I think I'm gonna get the Begi spacer, waterneck and cap, a 190° Stant thermostat, and the GM hose, keep the heater core and call it a reroute. Am I missing something?

weight, potential leaks, engine bay room around the back side of the turbo, and reliability. Those lines need to be protected from the turbo heat so they don't break down over time or just plain melt.

see above

Technically yes, but if you're relying on the heater core to keep your engine cool you have bigger problems. Such as not having a reroute, a radiator that's too small, or inefficent or no ducting. The later being the most important.

What's "waterneck and cap". You mean you're going to plug the 1.6 unit? It'll be too tall, and will hit the firewall. You either need to grind down the fan sensor threads and weld it shut, or buy BEGI's KIA unit, which doesn't have the threads cast in.

I have limited knowledge and therefore input about deleting the heater core, there's no way I'd ever take it out in the PNW, so I haven't given it much thought. Why the 190* thermostat? Also, see Joe Perez's video about Stant thermostats, I believe they've proven to be less than ideal.

There's some other good info in that thread about thermostats. Technically a hotter unit won't effect the cooling capacity of your motor, as even the best are above 190* at race conditions, but I don't see why you're going 10* hotter with a thermostat when you're also considering deleting the heater core.

Sorry I was unclear on the "water neck and cap" I meant the begi water neck and the begi block off plate.

I'm not going to delete the heater core right now. I have a supercharger so the heat around the heater core lines isn't as bad as with a turbo. I think.

On the 190° thermostat, I thought I read that was the one to get somewhere in one of these threads, but I'm not beyond being confused. Thanks for all the info. I'd like to get this all sorted before the motor goes back in. Looks like a royal, frustrating pain in the knuckles to do it with the motor in.

NB thermostats are 192*.

Hi,

I'm doing now the reroute for my eunos with g-reddy (1.6)

https://www.miataturbo.net/attachmen...ine=1326036664

So in the middle is the piece from the back-end of the engine. I suppose that is the temperature sensor for the ecu.

On the left is the temperature sensor for my own temp -gauge.

What is the sensor on the right -side piece? The one with the black hat.

That's the Tstat cover from a 1.6 that is OEM on the front of the engine. The sensor runs the radiator fans. In the stock configuration if you don't hook it up, the fans run constantly.

Ok. So if i would use the piece in the middle to block the stock thermostat housing in the front of the engine, can i put the sensor that runs radiator fans in there? Or can i put the sensor for the ecu in that place? Or does that give the right temperatures from the engine?

You might be able to use the rad fan switch there but that water is going to be significantly colder than the water coming out the back of the head. I was told I could use the rear sensor to activate the fans on my 1.6 car, but it's never worked right with MSpnp.