I'm putting an engine in the racecar today and need some help on the heater coolant line from and returning to the engine. There is an exit line from the engine just upstream of the thermostat. This is where hot water leaves the engine and goes to the firewall and to the heater. On the end of the cylinder head is the return line where the water from the heater comes back into the engine to recirculate. It appears that this water will have never routed through the radiator for cooling.

Obviously I have no heater or defroster on the car so should I simply hook these two lines togther so it leaves and returns uncooled but still circulating or should I find way to plug them off (not sure how)? Or finally should I hook a hose up between them and just plug it? Do you want some recirculation to occur even when the water is not hot enough to open the thermostat and let it go to the radiator for cooling? If this was plugged and the thermostat is unopened yet because it wasn't hot, would the water pump build up to pressure then just churn and cavitate until the exit path to the radiator was opened and some circulation should begin?

While writing this, I think I'm leaning toward hooking it up unplugged but don't really know what to do.


[Modified by CRX Lee, 5:12 PM 3/15/2003]

 

Dont forget to check the rulebook - i think there's some wording for SCCA's IT classes for this but i cant remember what it was.

I'd just let it circulate.

 

In IT your heater core must still be present but not necessarily working. Since it is there, it is a good idea to leave your defroster working in case of a rain race to remove fogging. This is on my Prod car so there are no rules pertaining to it and no remnants of the stock dash, heater, or ducting.


[Modified by CRX Lee, 5:30 PM 3/15/2003]

 

Lee,
Here is what I am doing & why. I ran the car all last year without the heatcore & components. I started out using the caps that you can get from the auto parts store. The rubber is definitely not as robust as heater hose. The first pair developed cracks quickly. Not wanting to take a chance, I switched to a new pair. These also developed cracks after one late spring enduro. I then switched to some generic heater hose making a loop. The car has run that way since August which has included approx. 30 race hours. No problems. No worries of sudden coolant lost & the resulting head damaged.

 

So you've got the hose there unblocked to allow the circulation or did you put the hose over the caps to have it be blocked but then give a rerouting if the caps failed?

 

Hoses are unblocked so that water sees an open passage. I think that there must be some circulation going thru the hose (laws of thermodynamics??).