As seen on miata.net

What do you think of this idea I came up with? It seems clever to me and easy to implement, but would this break anything? I have attached an image, please check it out.

The idea is that since there is more than average amounts of pressure just after the water pump, why not take some of that extra pressure and use it to feed the heater? And instead of taking water out of the back of the head to feed the heater, why not use that hole to feed the back of the head from the radiator?

It seems this would
-cool the back of the head
-maintain more flow of coolant through the engine
-keep the thermostat at the hottest part of the engine
-retain stock heater functionality
-be easy to implement

Potential downsides?
-bottom of engine gets mostly hot coolant left over from the heater core
-engine temperature reads lower because coolest water is entering back of head near sensor
-not enough coolant reaches radiator because of T junction after pump

Solution to downsides
-bottom of engine not getting most of heat anyway, ignore problem because circulation will mix the warm water from the bottom with the cool stuff flowing through the top
-use small diameter hose to restrict flow to heater so most goes to radiator
-ignore engine temperature, use something like CHT or oil temp anyway

 

And the inlet of the water pump only sees the heater core?
Then all of your flow will be through the heater. That's very bad, because the heater is restrictive.
And then your coolant splits between the radiator and the heater. Very very bad.

 

Wait, isn't the water pump on the front of the engine, pushing water forward to the top of the radiator?

My intent was to have the heater core dump into the mixing manifold as normal and have it fed from the tube between the water pump and the front of the radiator. I thought that was the outlet, not the inlet of the pump. Am I wrong?

The vast majority of water flow should be through the top radiator hose with only a little bled off to feed the heater core. The restriction of the heater core helps stop it from stealing all the water flow intended for the radiator.

 

Oh and thanks for supporting ron paul.

 

Oh wait, I see what you mean. I thought the pump sucked in from the whole engine and spat it into the radiator. If it sucks in from the mixing manifold and spits it into the block and radiator simultaneously, that complicates things.

I saw your car in CA like 5 years ago but I can't remember what you did to the cooling system.

 

I dont think that this setup would work, the inlet to the waterpump needs to be fed from the bottom of the radiator. I dunno how the normal coolant reroutes work, but I think it would work better to leave the routing from the bottom of the radiator stock. For the top of the radiator, you would pull the water from the back of the head, use a thermostat in line, and block the front thermostat outlet.

 

Thanks dude. I figured it out after talking to some people on the other board.

My only problem now is how to do the reroute without having to remove the engine.

 

Working on the reroute as well and while you don't have to remove the engine, it does make it infinitely easier to remove at least the head.

 

I've used this pattern on 1.6 and 1.8 with good results. Just don't go low with the return from the back of the head to the radiator or you will run into air blockage problems.

Also drill a 3/16" approx hole in the thermostat flange so that constant water temperature is seen by the thermostat and it can react correctly.

 

Isn't coolant coming OUT of the heater core cooler than coolant going IN? The heater core is just a radiator and a fan in an enclosed box. Air flows over the hot radiator and is blown into the cabin, right?

 

Totally correct. We have two radiators on our Miata. The problem that we correct with the reroute is flow. One radiator(the heater core) operates until we reach the thermostat temperature, and we then open the second radiator(the real one).

When the thermostat in the stock position opens, a lot of the flow can bypass the engine. With this reroute, we force the full pump output through the engine to both the radiators when the thermostat is open.

 

If you're going to go ahead and do it, wouldn't it also be wise to route the coolant out of the heater core between the radiator and thermostat to ensure only "cooled" coolant goes back into the block?

 

Crap, what kind of air blockage problems? Would a sloping return help any? I ask b/c I was planning on going low....dang.

 

It would take longer to warm up the heater and the motor. Probably fine for track cars and high hp sunday drivers. Probably not ideal for daily drivers.

 

Coming off the back of the block and going real low will give you trouble "burping" out the air when filling with coolant.

On my 1.6 I came out the back on the passenger side with a line even with the back outlet and kept it relatively level coming forward.

On a friends 1.8 we came out above the turbo(low MSM) and forward. The piping looks like **** right now, but can be dressed up shortly.

I understand that Turbo Tim went lower and hit problems.

 

The too low issue is why I have a very high filler location... and my coolant reroute runs over top of my Intake Manifold. Without a proper burp... coolant systems can get quite grumpy.

 

Why would you need to remove the engine?

 

Don't thank me, I did it for selfish reasons. I want taxes to go down, the economy to improve, the Compound Interest Paradox understood, the lobbyists to lose influence, Habeas Corpus to be re-instated, the Constitution followed, and the government to shrink and keep its nose out of my daily life.

 

I dressed his up somewhat.

Yep. It takes me forever to burp the air out of my engine. I run the head-to-radiator line on the passenger side, under the intake manifold. I will be redoing it all to be more horizontal & stainless when I install my new intake manifold.

 

Someone plez post sum pics!!! REAL PICS!!!