Visit The Dirt Forum for More Information

Author Topic:   cooling question
posted April 27, 2003 08:57 PM
Have a question. Was testing the car today and turn temps of 230-240 while racing. After coming back into pits and revving to 2000 rpms. cooled back to 200-210. Have any ideas on keeping the temp a little lower while racing.

Info: Timing is at 34 deg.
9:1 350
Turned 6300rpms
outside temp was probably mid 70's

have some holes cut in nose cone, but room to cut more if needed?

if you need more info let me know

Thanks in advance

jhon hollomon
posted April 27, 2003 09:07 PM
Are you running an aluminum radiator? Do you have a fan shroud? Do you have a restricter in your water neck?

posted April 27, 2003 10:13 PM

Yes, Yes, and Yes.... ha ha.

Seriously though the answers are all yes. One thing I was going to change is bringing the fan out of the shroud a little more. I think it may be set in a little too much. Looks like its set in a little more than 50%. I always heard to have the fan split half in and half out of shroud.

As for the restrictor, I believe it is a washer of some sort. I will be checking that tommorrow.

What do you suggest for restrictor size, etc.

[This message has been edited by sjakes (edited April 27, 2003).]

posted April 27, 2003 11:40 PM
The restrictor I use I just made out of an old thermostat. I just cut all the stuff off of it and left the hole in the middle. Worked good for me.

posted April 28, 2003 06:50 PM
ok got this far....

original opening in therostat housing is a 2" opening, the washer thats in it leaves a 1" opening.

Should I go a little smaller with restrictor/washer?

Also Pulleys are sizes as follows;
water pump is 7"
damper is 5 1/2"
both deep groove.

I would believe water pump is factory water pump.

One other thing I was gonna try is move the fan out of the shroud a 1/2". Its a little further inside shroud than out. Sound right?

[This message has been edited by sjakes (edited April 28, 2003).]

[This message has been edited by sjakes (edited April 28, 2003).]

posted April 28, 2003 07:01 PM
i'd put a restrictor like jhon mentioned also cut some more out of your nose also might look into being to lean or a vacume leak use some wd40 around the intake and see if the rpm's pick up at all wich would indicate a leak

posted April 28, 2003 08:16 PM
How do you guys feel about the aftermarket thermostats from JR motorsports, or speedway. They say they are 180 or 195, and they are hi rpm hi flow??

I also am getting the restrictor pack also comes with 1", 5/8", and 3/4".

Now the decision is what to try first? Thermostat or a restictor, and what size restrictor? I have the 1" in now.

Also what temp is the most you would let it get to before shutting it down? Like I said earlier It went up to approx. 240 on sunday.

Thanks again guys!!

posted April 29, 2003 04:00 PM
no needs for any thermostat i have used a gutted out one for years and never had heating issues becuase of that mine was always jets, timming, and air flow to the radiator that caused me to over heat as for what temp 235 and i'm out

posted April 29, 2003 05:29 PM
I use a 5/8 restrictor I feel there are several different combos that will work pulley sizes, fan sizes ,water pumps ,there are a 1000 different combos you could come up with .Everything you have sounds good. I think you are close, but Im gonna bet ,on an extended run you could stand to be a little richer on jets and you would be fine .But then again I always work on mine so I dont have to cut holes on my nosepiece and fill the radiator full of dirt it can be done....just my opinion ....towman

posted April 29, 2003 06:05 PM
You were just reading my mind. I checked plugs and they look.... to me just a bit lean. Now my question is, they have Holley 73's in it now in a rochester 2bbl.

Do I just go up one to a 74? I really haven't played with jetting all that much. My last car had 73 and was the way to go without any problems.

Also I have anti-freeze still in motor from winter, so I hear that may be another reason for the hi temps?? Water will cool easier.

So a nice recap of what I'm gonna try for this weekend:

-Try riching it up a notch to 74's (jets) should I go more?

-Moving the fan out of the shroud 1/2" so the fan is half in/ half out of shroud.

-take out the anti-freeze replace with water

-changing restrictor from 1" to 3/4" hole size or would you go all way to 5/8"? Do I worry about to much restriction? I have the restrictor kit with all three 1, 3/4, and 5/8" to choose from.

-stand on my head and pray I run cool

With all these changes I should have ice forming soon..... ha ha.

posted April 29, 2003 06:09 PM
Also one more question is the timing?

It runs good with 34 degrees, would it be smarter to back it down to 32 or so?

posted April 29, 2003 07:16 PM
you need to go up at least 3 jet sizes to really notice much of a difference.

posted April 29, 2003 08:11 PM
so what you are saying about the jet sizes is to raise mine up to 76 from the original of 73? I just don't want to be too rich? My guess is I wouldn't find that out until a couple laps into the feature don't you think?

posted April 29, 2003 08:35 PM
shawn just go up 1 jet size at a time,and try the 5/8th restrictor you can also build a air scoop under the front bumper to send the air to the radiator

Back to the Archives