Visit The Dirt Forum for More Information

Author Topic:   overheating
posted May 13, 2002 10:26 PM
any hints on preventing overheating??..we race in Lubbock, Texas..ambient air temp in the high 80 in the heat races..we run aluminum radiator, 1 to 1 pulleys..half water/half anti-freeze...but lots of guys still appreciated.....thanks.....Chuck

posted May 13, 2002 10:38 PM
try a solid ford fan off a truck(four blade), get radiator a little closer and a good full circle shroud, maybe even make a tunnel that pushes air into the radiator

posted May 14, 2002 07:37 AM
Afco makes the same 4 blade fan that Evans is talking about, if you don't want to go to the scrap yard.

Also, do some reading in the tech section at I think you'll be surprised at what they say.

posted May 14, 2002 07:48 AM
myself i never run ani freeze in a race engine also your jetting and timing can help cure heating problems and also make sure your getting enough air to the radiator even the stock grille on most cars will restrict air enough to make it over heat

posted May 14, 2002 08:10 AM
if you are running a restrictor get rid of it, you need the maximum flow in order to get the water tumbling and swirling for maximum heat absorbtion (in the engine) and rejection (in the radiator). Also since your in Lubbock make sure all of the dust is wash out of the radiator.(LOL)

It nice to hear from a racer in Lubbock, lived there for 10 years


posted May 14, 2002 08:54 AM
Different things work for different motors, but without a t'stat or restrictor, the water moves too fast thru the system. Then the water can pick heat up as well from the block. I've run a bunch of demo derbies and found that a poor man's restrictor (thermostat with guts tore out) does a better job than being open.

Also, a t'stat helps a race motor get warmed up quicker. I like not burning off any more $4 a gallon gas than I have to.

My opinion is that running no t'stat or restrictor is a band aid. An air dam below the radiator can help a lot, but make sure its made of plastic. I tore up my lower radiator support with an aluminum one.

posted May 14, 2002 12:13 PM
Check out this site, they have alot of good info. I never run a restrictor.

Smith Racing Team

posted May 14, 2002 12:18 PM
I am about to put my new stewart water pump on and I have always run a restrictor, but I am going to follow their recommendations and run without I'll let you know how it works.

posted May 14, 2002 12:35 PM
Okay here is my two cents worth.
All of the talk about restictions in the cooling systems does get a bit confusing.
If you have a good radiator, good pump, good belts and not collapsing the suction hose then we should not have any heating problems.
So why are we trying to band-aid and fondle these systems to make them work. My engineering mind has been contemplating this idea. The radiator that we all are required to use (stock) was designed for a certain anticipated flow rate coming to the inlet. We tend to exceed that with the RPMs we turn. I too am wrestling with the heating issues and have noticed that the top part of the radiator gets much hotter than the lower part. And I have a new one installed. So does that mean only the top part of the radiator is working. Well consider that pump is pushing hot water into the small tank on the side. The cooler water at the bottom of the tank is harder to push than the hot water near the top. So that along with the velocity we are creating forces the water to flow only cross the top portion of the radiator. Now on the other side of the cooler is the suction that is directly below. I may be full of crap here but I think that different pulley sizes and restrictors are band-aids and we need to find those cross flows that are coming out on the newer vehicles. Else work with the local Rad shop to design some baffles to create our own cross flow radiators and make them suckers work for us!

posted May 14, 2002 12:41 PM
Ryan, just make sure you follow all their recommendations. I followed it to the letter, and have had no cooling problems at all over the past 2 years.

What "stage" pump did you buy? I used a stage 3 last year, this year I'm using a stage 4.

posted May 14, 2002 08:09 PM
OK this is what i did to cure cooling problems. Take out the center section of thermostat this will restric the flow. Use a 17" 6 blade fan. Shroud the fan so that 3/4" of the fan is into the shroud. Build an air dam in front of the radiator. Use 1 to 1 pulleys. Use plain water and water wetter. Coolant will actually increase your temperature. DO this and you will run cool all night.

posted May 15, 2002 12:19 AM
Stage 1
I read their tech pages and the only difference between 1 and 2 is cast vs. aluminum and the only difference between 2 and 3 is the hub. I am on a budget so I get what I can afford.

posted May 15, 2002 07:39 AM
That's my understanding of the differences of the stages too, ryan. The stage 4 has some sort of special designed impeller that is supposed to reduce drag, using less HP.

Good luck with it.

Another thing that I've done is use copper radiator hose, for a little extra cooling. See

posted May 15, 2002 05:06 PM
Apart from checking the obvious (timing/jetting) you could try adding extra cooling pipes from the rear of the inlet manifold to a modified thermostat housing (if the engine is mounted level in the chassis instead of about 5 degrees nose up like it was intended to be run then you can get air locks at the back of the engine wich hinder cooling). Plus you could try running a couple of lengths of 2 inch bore flexible pipe from just forward of the rad, cable tie them to the underside of the hood so that they duct cooler air direct to the carb.

posted May 15, 2002 05:40 PM
If you are doing everything right, then maybe something else is wrong? I saw a guy once that put a water fire extinguisher in his car and ran the outlet up to in front of the radiator, then when the car got hot he shot it with water for 5 to 10 seconds and bam!! the temp would come down. something tells me the rules might frown on it, but maybe cost of new engine would override the rules.

posted May 15, 2002 08:30 PM
In New Mexico almost everycar has either the fireextinguisher you talked about or a boat bilge pump in a 5 gallon gas can filled with water. After listening too all the suggestions on this site good fan, fan shroud and washing the dust out of the radiator after each race i haven't used it in over a year.

dryslick racer
posted May 15, 2002 10:16 PM
Here's another trick I learned from my dad.Put a tee fitting in the top of the water pump {on the suction side of the impeller} run two 3/8 or 1/2 hoses {one on either side} down to the drain plugs on the side of the block. This cooled our 406 off 15 degree's. From 220 to 205 while racing. You also may want to use a bigger pulley on the water pump to slow down the coolant.

posted May 15, 2002 11:23 PM
51 we do that after the race myself i don't like, the idea durring on a dry slick track running over the water that my buddy put her in the wall one time because his overflow went off and the tire just slid and dirt most of us don't have the time money or resorces to desing a new radiator so using this stuff is our only hope

posted May 16, 2002 12:18 AM
I think 17j has stumbled onto something and he doesn't even realize it epescially if you start on the pole. Instead of one spray bar pump for the radiator have two. One by the radiator the other on the rear bumper. You could make your own little booby trap kinda like an oil slick or smoke screen on t.v. When your in the lead just spray a bunch of water down and laugh as they spin out. lol

Back to the Archives