To thermostat or not to thermostat

[JeffYoung]

so the gasket on my thermostat housing is leaking, and I either need to replace or it could dump the thing. Any thoughts on this? Small issue I know, but I've heard different viewpoints. Some say dump it to avoid a problem with the thing. Others say keep it as it helps with engine warm up, etc.

Votes?

[moto62]

I say keep it but replace it with a 'Failsafe' brand one available at most part stores. Something about it only failing in the open position, if it does fail, thus preventing any overheating issue.
Ray

[Banzai240]

Originally posted by JeffYoung:
Some say dump it to avoid a problem with the thing. Others say keep it as it helps with engine warm up, etc.

Votes?

Keep in mind that the thermostat also controls the water flow when the engine is warm... If the water moves too fast through the radiator, it's not going to transfer it's heat to the air as efficiently. If you remove it, make sure and put in an appropriate restrictor for your application. Don't know exactly how to tell you what that may be, but what I did was just remove the guts from my thermostat and use it for the restrictor... Kind of like having it fully open at all times... Seems to work alright.

I am going to experiment with using a new thermostat this summer, as I believe that ECU controlled cars require a more precise water tempurature than non-ECU cars...



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Darin E. Jordan
SCCA #273080, OR/NW Regions
Auburn, WA
ITS '97 240SX

[Bill Miller]

Darin's right, it impacts the water flow. In some cars, like a VW, it actually blocks the bypass loop. Without a t-stat, the water won't circulate through the block as well. With VW's, they're somewhat of a pain to get all the air purged out of, so I always drill a couple of holes in the side plate. Lets water through, but doesn't let it blow through.

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MARRS #25 ITB Rabbit GTI (sold) | MARRS #25 HProd Rabbit
SCCA 279608

[Harry]

I use restrictors of different sizes based on ambient temperture. Can anyone guess as to which size (sm, med or large) goes with with what weather real hot, regular & cold.
Harry

[Knestis]

Medium restrictor for "regular" weather. What do I win?

K

[RSTPerformance]

we take out the thermostat in our Audi's... We had overheating problems until we took it out, droped the tempature by at least 50 deg. You can idle the car without the fan on and it will never overheat. It doesn't seem to take much longer to "come up to tempature" with or without the thermostat (although I would agree that it seems like it should take a lot longer).

PS: answers to your questions;
Hot (small restrictor, larger hole to allow better flow)
Regular(medium restrictor)
Cold (large restrictor, or smaller hole not allowing much flow)

Raymond Blethen

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RST Performance Racing
www.rstperformance.com
1st and 2nd 2003 ITB NARRC Championship
1st and 6th 2003 ITB NERRC Championship
3rd 2003 ITB ARRC Sprint Race
4th 2003 ITB ARRC Endoro
1st 2003 AS NERRC and NARRC Championships

[Harry]

Thanks I needed that! 1 DOWN TWO TO GO!!

Dirty Harry

Raymond wins!

[This message has been edited by Harry (edited January 08, 2004).]

[racer_tim]

Harry, on my VW, I just took a standard thermostat, and removed the center section. I'd say that the overall diameter of the entire unit is around 2" and the "restrictor" is about 1" now, so that's about 1/2 reduction.

I don't have any problems with over-heating, but it does take a little longer to get the water temp up to normal.



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Tim Linerud
San Francisco Region SCCA
#95 GP Wabbit (Bent)
http://linerud.myvnc.com/racing/index.html

[bill f]

Had to add my money (two cents) to the pot...

We have always run a thermostat and never had a failure, using water/water wetter combination. It gets changed at the start of every season.

As to why: I believe in a quick start-up to minimize wear, since that is the reported max wear operating point of reciprocating engines. We race from early spring (40-50 degrees) thru summer (90-105) to the fall 30-50's). We never had a fan on the car for summer, and have heat very quickly in the car. Incidentally, our radiator has been smaller than usually run in that chassis, which would have made any cooling problems worse.

I haven't used a restrictor since the 70's, so I don't know if there is a temp difference due to the less restriction of the blank, compared to the mechanism at the center of the thermostat. I definately know that the removal of the restrictor has raised the operating temp compared to the restricted flow thru the engine.

Good racing.

Bill

[RSTPerformance]

Originally posted by RSTPerformance:
we take out the thermostat in our Audi's...

WE actually only took out the guts so we effectivly still have a restrictor. It definetly helped at idle since the car doesn't have to come up to tempature before it opens, nor does it have to wait for the fan instead you can run the fan all the time and let the water continue to run.


Stephen

[Joe Craven]

I always run a stat except in my 1980 200SX race car which overheated with one in the car.

I've had problems with running my motors too cold, and the stat keeps the temperature of the motor constant. Constant temps assist the motor in putting out maximum power.

ITB this year.