Did some more research on my particular car. I've got an Escort GT engine with 2 water exits on the back of the head.

Miata:
http://users.telenet.be/miata/images...rear_plug1.jpg

Escort GT:
http://users.telenet.be/miata/images...323fitting.jpg

So it appears that that fitting flows pre-tstat, so I found a hose at Autozone that had a 180 degree bend near the end of it and ran it back towards the driver's side and just put a barbed fitting (male on both sides) in between the stock heater hose and it. Just another reference for guys with EGT swaps in their cars.

Yes. That config would work properly for a heaterless car, and would eliminate the need for a spacer and thermostat at the back of the head.

https://www.miataturbo.net/attachmen...2&d=1314749775

Im using a Perma-Cool Oil thermostat in my heater core line.

http://www.alamomotorsports.com/pmc/Cat_page14.html

You plug two of the ports and use the other two and you can configure it so it shuts off flow once up to temperature. Testing it I found the Wax plug in it was too high temp and didn’t fully shut off flow until about 200F if I remember right. I took it apart and found a Motostat radiator thermostat at Oreilles that was listed as a 170F. It had the exact same shape wax plug in it like in the oil thermostat that came with one rated for 190F. Put it in and I had a thermostat that was fully closed and shut down flow at roughly 180F.

I still have my heater core but with the thermostat post core. It dosn’t let much of any flow bypass the radiator unless the heater core heat exchanger gets it to below 180F. Thus maximizing the flow to the biggest most efficient heat exchanger when needed. The main radiator thermostat is also 180F.

Im using a 1070 that has 1/2" pipe ports and using -10 AN lines. but I see that part number 1071 comes with -10 AN ports and might be more compact with fittings.

Turn the blower motor heat on in the cabin and it will heat the car turn it off and the heater circuit won’t be bypassing the cooling system if more heat transfer is needed.

Eliminate the heater core and I think it would still work good as well. Though I have seen it work with just capping off the heater circuit. The water pump is not positive displacement I think it will just churn the water in the block until it warms up and the thermostat opens and things begin to circulate.

Bob

I must admit I have toyed with the Idea of alternate coolant ports in the head. Attached image of a friends Alfa. 2.0l NA cerebrated and it made over 200hp. He reverse flowed the coolant system putting the cool water into the head directly on top of each combustion chamber. If you pull the valve cover off a Miata head there are two big pipe plugs staring right at you in the valley already going to the water jacket between 1 and 2 and 3 and 4. The only problem is getting through the valve cover with it.

But I still don’t think it is necessary with a miata as I think we have found other setups that work good enough even into the 350+ hp range on track cars.

Bob

I also must admit I am skeptical of the PWR 37mm radiator in its ability to be much more effective than the stock radiator at transferring heat. I’d like to see some independent scientific testing. I think FM did some testing that showed this as well. The stock one seems to be light and small but it must be really efficient for its capacity. I noticed a huge change going from a PWR 37mm after it split to a cheap Ebay 52mm thick Mishimoto copy and almost no change at all in performance when I went from stock to the PWR. The only problem with most of the really thick ones is filled they weigh roughly 3X the stock weight and add like 15 lbs to the nose of your car.

It seems the cross flow multi pass types offer even better performance I’m guessing.

Bob

This guy is a fucking genius

So, just found out my heater core is fux0red.

I never use the bastard anyways, move thermostat+housing to rear, drill pee-hole out to be larger, route rear thermo housing to radiator, profit?

A bit of thread necrophilia but I'm researching this for my project. The image above from the escort GT shows pre-stat water that could feed the heater core with the 'U' turn hose but even on the miata head, the water to the oil cooler looks like it is moving pre-stat. Does this alleviate some of the worries about water not flowing in heater core bypass designs? Would that double dong outlet on the escort head thread on or press on? I wonder if there's a part # for it to put one on the Miata head...

Here's my tentative plan if I can find the escort outlet: Use the Kia neck and the GM hose like many do and use the U turn hose from the escort outlet to plumb the heater core. The factory temp sender looks like it will thread into the bung that is plugged on the miata head and with a reroute, this is the best place to get the water temp because it's the hottest point in the system. Besides that, all I need is to plug the front and route the oil cooler return to the mixing manifold. Did I miss anything?

On a side note, there hasn't been much discussion in this thread about the head gasket issue in the later 1.8 motors. Mazda changed the head gasket in the VVT motors to bandaid the coolant path. If you do a reroute on an '01 and newer 1.8, the #1 piston will be even worse than #4 is stock. Use the '94 to '00 head gasket in that application (BP26-10-271).
-h

I have a couple escort GT heads in my shop. Yes the Biger outlet on the double dong is used for the Heater core on a transverse engine installation.

I suspect it would be hard to get out of the head without mangling it however. I might consider just taking it out and tapping it to screw in an AN-fitting. I am currently using a spacer on mine but have converted all the Heater core lines to AN fittings and hoses. Actually welded on AN-bosses onto an NB heater core.

Bob

I think a similar fitting is in most/all of the BP heads used across the different marquees so hopefully I can find a parts counter that will sell me one. Are the AN fittings at the heater core because of any unusually high coolant pressures in your monster block or just to make the engine bay look even meaner than it already is?

http://users.telenet.be/miata/images...323fitting.jpg
I test fit the Kia neck tonight. This isn't a news flash for anyone who has used the BEGI kit but it runs right into the double dong nipple without the BEGI spacer. I still like the concept so I'm going to see if there is a BP water neck that clocks another 30* counter clockwise to an exit around 1:30 instead of directly to the right. That should still be a gentle enough bend to allow the use of the GM hose.

Here is what I did.
http://memimage.cardomain.com/ride_i...7_original.jpg
http://memimage.cardomain.com/ride_i...8_original.jpg
http://memimage.cardomain.com/ride_i...2_original.jpg

well aparently cardomain wont let you link photos anymore and new security at work wont let me upload. here is the link to the page.

http://www.cardomain.com/ride/737924...e-9#7379240132

I believe this is the image he wants:
http://memimage.cardomain.com/ride_i...arge.jpg?modal

http://memimage.cardomain.com/ride_i...arge.jpg?modal

This is the image of the day:
https://www.miataturbo.net/attachmen...ine=1323322244

I got the BEGI spacer in a box of other stuff for a good price so the next wheel I need to fuck up reinvent is the water return. I want to run the heater return into the upper radiator hose (post t stat) and cap the extra pipe in the mixing manifold. Has anyone seen an OTS Y pipe that will allow this or do I need to beg someone with more skills than me to braze one? I've pieced out the assembly of one with brass plumbing fittings (barbs, NPT, etc.) but it would be $100 and weigh 10 pounds.

You can weld the "mixing manifold".

I just ordered a $.29 ~22.17mm freeze plug to plug up the unused hole in the mixing manifold...if it works out, I'll post part numbers...and more details. I'll probably throw a little epoxy around it as well just for safe measure.

Front and back of my mixing manifold, which has been turned around from the factory position, hopefully you can figure out what's going on. Big hole has been welded, drilled, and tapped for 1/2NPT. You can yank the hose barb out then drill and tap for 1/8NPT, which is currently plugged in my thanks to the waterless turbo.

https://www.miataturbo.net/attachmen...ine=1323841117

https://www.miataturbo.net/attachmen...ine=1323841117

If I did that, I couldn't have AC and power steering in my track car... :loser: I didn't think about flipping it around. Is there an OTS lower hose that works in that configuration?

Does anyone have the heater return going into the upper radiator hose? Pics?

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.

Ok. But on ms pnp, does the ecu need the water/engine temperature constantly, or just on startup? If on startup only the place i was thinking would just might work?

I don't think you can do that, it won't seal the stock water neck (not pictured) has an o-ring to seal it. Begi's cover is on top of that with a thermostat gasket, and we use freeze plugs. I don't think there's room for a thermostat gasket there.

If you want to bypass the stock ecu so its completely out of the loop and the fans are running on their own, run a thermostat on the bottom hose of the radiator. (160 degree thermostat sensor) Preferably if you have an aluminum rad, weld a bung right at the bottom. What this will do is keep your radiator full of cooler water regarding of engine temp. The thermostat at the engine outlet will control flow to this cooler coolant in the radiator.

What is the function of this part: http://www.mx5parts.co.uk/valve-mazda-p-773.html

Can i just take it off completely and leave the holes in the manifold open?And why is it called air valve?

Can someone please give me some information on how to do that? I know Trackspeed offers a freeze plug for where the neck is, but what do I do with the other plumbing?

Thanks.

Late to the party, but for future reference...

This device was used on the '90-'93 1.6l engines in the US, and probably elsewhere. It is a thermostatically-controller air valve, which sits inline with an air passage cast into the intake manifold, which draws are in from a bypass hole cast into the throttle body flange, and dumps it into the plenum.

https://www.miataturbo.net/attachmen...ine=1334695713

It is controlled by the temperature of the coolant flowing through it, allowing a bit of extra air into the intake when the engine is very cold. The factory manual test procedure calls for it to be cooled to 32°F, but does not give an actual spec for what temperature it normally opens and closes at in typical operation.



A lot of folks think that this valve was unique to the 1.6 Miatas, but the '94-'97 cars had it as well. On that application, it was integrated into the lower section of the throttle body, in the same housing as the IAC solenoid.


https://www.miataturbo.net/attachmen...1&d=1361124623
It's the part labeled "Thermowax" and "Air Valve."



Just remove the hoses from the throttle body and air bypass valve, cap them off with rubber plugs (optional) and install a new hose between the port on the lower intake manifold and the port on the thermostat housing (if present) or mixing manifold where the hoses you removed from the throttle body and air valve came from.

Zombie thread revive:
Is the Kia thermostat housing cover the same as the water neck?
Searched all the old threads, the JC Whitney part number pulls up nothing. Found this guy on Amazon for $12.26 though...
https://www.miataturbo.net/attachmen...ine=1361121967
ASIN: B004HOA00U
Item model number: 311-0024

same-same?

EDIT: Just compared it against the BEGI website, appears identical, down to the "2-2" stamping on it.