Coolant: Heater Core Capping Off

[ixfxi]

I've heard discussion that capping off your heater outlet and inlet can be a bad idea because the water doesnt circulate, and that a constant circulation is needed to keep the head at optimal temperature. But something doesnt make sense.

I mean, the thermostat is responsible for opening and closing when necessary. But there are folks that think the heater core flow, or that a source of flow is required in the head besides the thermostat.

I've been thinking long and hard about this, and it seems like rubbish. I mean, it seems that people are over-thinking about coolant. Before coolant, cars were air cooled with oil in the block. Now we add coolant into the mix and thats the whole point of the thermostat, it opens up when hot (and it gets hot relatively quick) and wallah, theres you're cooling.

So, whats the point of having secondary circulation. If I recall correctly, I swear I've seen the S14 having a valve that TURNS OFF flow into the heater core. I'm almost 100% sure of this, because it did not exist on the S13. That valve means NO FLOW, OFF. So....

I am asking this question to the smart 240SX owners, not that I am capping off the coolant on my S13.. but doing so on my Miata. The Miata owners / forums are practically useless, I despise these guys and wish not to associate with them.

So, please advise.. I'm curious what your thoughts are.



Fuck, I hate Mazdas.

[ixfxi]

http://users.telenet.be/miata/images/coolant_reroute/my_reroute/m2_head_rear_plug1.jpg
Also, does anyone know if the above item with arrow pointing at it, the coolant boss, if its removable? It appears to be pressed into the head, I dont think its removable. But just curious.

[japslapsilvia]

the s14 has the valve for the heater core inside the engine compartment. the s13 has it on the heater core itself. when you slide the temp selector to hot, it opens that valve to allow coolant to flow in the heater core.

i wouldnt cap the lines, i would loop it, but i would have to see a flow diagram of the miatas cooling system to say yay or nay. looping lines would only mean the core isnt present and water/coolant will flow like normal.

edit.

yes its it pressed in and it can be removed.

[hulkster_s13]

It may be harder bleed but I have mine capped and not looped. Never had a problem until recently with the bleeding process. But it's all good now.

[ixfxi]

http://users.telenet.be/miata/images/coolant_reroute/ScottIngram_reroute/Coolantrouting.jpg

pic of stock setup. apparently mazda hired elementary students to do the work. heater core is ALWAYS active and my feet are ALWAYS hot.

[h2v7]

get one of those mustaches on front of your car and be done with it

[Sileighty_85]

Judging by the Diagram I would say loop the Heater core hoses, if you look in the engine on the diagram it shows that the coolant flows though the cylinder water jackets and out through the heater core.

[ixfxi]

Judging by the Diagram I would say loop the Heater core hoses, if you look in the engine on the diagram it shows that the coolant flows though the cylinder water jackets and out through the heater core.

Correct, but I will be eliminating the front coolant outlet (reroute) through the rear of the motor where the heater outlet is. The problem with this motor is that its originally a FWD motor that mazda installed into the RWD Miata.

Thanks for the info

[Sileighty_85]

Correct, but I will be eliminating the front coolant outlet (reroute) through the rear of the motor where the heater outlet is. The problem with this motor is that its originally a FWD motor that mazda installed into the RWD Miata.

Thanks for the info

I see, the outlet seems its big enough to work.
But seems bleeding the air might be an issue?
Is that where the Thermostat is located?

[ixfxi]

The outlet is equally sized as the front. The engineers machined a thermostat provision in the rear outlet, thats where it resides in the FWD vehicles. In the miata, there is a thermostat housing which looks very tacked on, and its located smack dab in the center of the motor under the cams. Remove the housing and it can be plugged with a simple freeze plug.

Its a hassle, these cars suck.. but such is life. Lesson learned, f-mazda.

[H_K_S]

I know I'm bumping an old thread, but this what connects to the lower part of the throttle body, yes? If so, I blocked that off and ran I line from the metal pipe to the right of the thermostat, to where it plugs into the block right above the oil filter. That was really hard to get to. .I did that because I was missing the stock stuff after removing my supercharger..I was looking for a good diagram of the cooling system for the miata because I randomly got a coolant leak from behind the block yesterday and am trying to figure out what it is I think it's a heater hose as that's all I see, coolant wise, on the diagram on the picture.