I have a 98 ITR motor with I/H/E. On the track when in Vtec for long periods of time, the temperature starts to climb. I have a double core rad and run 75% distilled water, 25% honda coolant and water wetter. My theory is that the thermostat isn't opening all the way and is blocking the flow of coolant to my block. I've picked up a new ITR thermostat from the dealer. A drag racer friend of mine suggested that if I drill 2 3/8ths" holes in the thermostat - says it'll increase the coolant flow even more. Says he does it on his 9 second drag car with great success. Since mine is a road course car, I'm wondering if that's a good idea or not. Any ever try anything like that? Advice appreciated.


Modified by RRRex at 4:08 PM 8/18/2003

 

do not drill the thermostat.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Willard &raquo;</TD></TR><TR><TD CLASS="quote">do not drill the thermostat.</TD></TR></TABLE>

 

Why not get a Spoon or Mugen Thermostat? Road racing is what these were designed and tested for.

 

I've heard of people drilling thermostats, but I don't really see the benefit unless there is that rare instance where the t-stat fails in a closed position.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by zyg &raquo;</TD></TR><TR><TD CLASS="quote">Shouldn't you be running about a 50/50 mix?</TD></TR></TABLE>

While more coolant will provide better protection against freezing, straight water will have better heat transfer properties (and run lower temps). I would try a new rad cap (or make sure yours is working)

RJ

 

RJ is right - straight water is the best though it doesn't lube the water pump, which is why I run a bit a coolant and the wetter. I pulled the thermostat altogether for yesterday's track event and the thing still overheats. It's a full sized rad double core rad and provides more cooling than stock. I even hooked the fan up to the ignition so it runs constantly. I'm going to swap out the cap next. I replaced it when I did the rad, but maybe it's a dud. If that cap doesn't open when it's supposed to, doesn't that provide even more cooling? Maybe the rad is a dud, I'll have to get it checked. What are the signs of a failing water pump? Do they just go or do they just pump less?

 

if the cap is bad it is not letting the system maintain the proper pressure therefore the cooling ability of the system is less.
the higher the pressure the more heat it can remove from the motor.
try a new rad cap or even an aftermarket cap (spoon/mugen/etc)

 

Took the cap off another car and ran it today at an autocross. Started the course at 150 degrees (because of no thermostat) and finished it at 210 degrees. Don't think it's the cap.

Going to get a sending unit so I can run the stock temp gauge and the aftermarket one at the same time. Though I don't think it's the gauge, it was also overheating on the stock gauge before I bought the aftermarket one.

I'd like to check the rad, - either the hose method or find a shop that can test it somehow - but my guess is it's not the rad. It overheated the same with the double core rad as it did with the single core. They're both full sized rads and should be adequate to run my motor. Odds of both being duds is small, but still possible.

Head gasket maybe? The car was blowing white smoke a while back but that stopped when I went to the 15W50 oil. Now occasionally it blows smoke on startup. My mechanic said the head gasket is bad but not bad enough that it needs to be replaced right away. But maybe he's wrong - he never saw the car run on the thinner oil. Could a head gasket cause overheating?

Next thought is a failing water pump. Might not be able to keep up with the demands of racing. What happens when a water pump starts to fail?

 

TTT