Coolant re-route?

[vtluu]

Wondering if I can get opinions on the legality of this Miata coolant re-route kit:
http://www.etdracing.com/m-tuned/product_info.php?cPath=11&products_id=86

Basically the kit caps the existing thermostat housing (which would be allowed as thermostat modification/removal?), replaces the rear coolant temp sensor housing (which also holds the heater hose fitting) with one that fits both the heater hose and a hose to the radiator (replacing the hose from where the original thermostat was). Would the replacement housing be allowed as an added "heater water control valve" (maybe if I added a check valve in it)?

[Gary L]

If you can find an allowance in the ITCS that specifically allows additional "heater water control valves" (or whatever you choose to call it), fine. But I'm betting you won't. :)

[Greg Amy]

I'd vote for "probably not". But the more important question is, "why?" After all, with all the trick radiators available (thanks to Spec Miata) I'm not hearing of any massive cooling problems in Miatas...why add the complexity?

[ddewhurst]

****I'm not hearing of any massive cooling problems in Miatas...why add the complexity?****

Because the #4 cylinder runs HOT. I would exlpain in detail except that you would .............................:cavallo:

[Greg Amy]

I would exlpain in detail except that you would .............................:cavallo:
Huh?

[rhygin]

I have the BIG Koyo and my engine almost runs too cool... even in the summer heat. What is the temp diff for #4?

[vtluu]

If you can find an allowance in the ITCS that specifically allows additional "heater water control valves" (or whatever you choose to call it), fine. But I'm betting you won't. :)

9.1.3.D.3.g:

Engine coolant fluid, coolant/heater hoses and clamps may be substituted. Heater hoses may be plugged. Heater water control valve(s) may be added or substituted. Heater core and hoses shall not be removed.

The Miata cooling problem is basically this: when Mazda took the 323 transverse B6 (and its 1.8L version the BP) engine and shoehorned it into a longitudinal configuration, they changed a couple things to mount the engine as far back in the engine bay as possible: they replaced the distributor with coil packs, and they moved the thermostat housing to the other end (now front) of the engine.

The problem is water now leaves the engine through the thermostat housing at the front of the engine (to the radiator) and re-enters at the water pump on the front of the engine as well, so there is very little flow of water towards the back of the engine (cylinder 4). Bigger radiators etc. don't address this problem.

The coolant re-route kit restores the original water flow direction through the engine as it was intended.

[vtluu]

Another possible cure, since coolant to the heater core still runs from the back of the engine, would be to plug the existing heater core hard lines at the firewall, and run the heater coolant hoses to and from an auxiliary radiator. Would 9.1.3.D.3.a allow an auxiliary radiator to be added (as long as it's mounted parallel to the existing radiator)? Or maybe I could use the A/C condenser as an auxiliary radiator?

Or I could just turn the cabin heater on full-blast, but on the days where cooling becomes an issue, that's going to be fairly... unpleasant. :)

[Gary L]

9.1.3.D.3.g:Engine coolant fluid, coolant/heater hoses and clamps may be substituted. Heater hoses may be plugged. Heater water control valve(s) may be added or substituted. Heater core and hoses shall not be removed.

I could have sworn we had an Eating-Crow emoticon, but I don't find it, so this will have to do.... :blink: