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Author Topic:   COOLING PROBLEMS
new8
Dirt Full Roller

Total posts: 34
posted February 05, 2002 07:38 PM
I WOULD LIKE TO KNOW HOW TO CURE MY COOLING PROBLEMS? FIRST OF ALL MY TEMP HITS 300 DEGREES. I HAVE A NEW 3 CORE COPPER RAD,A HIGH FLOW WATER PUMP,A 7 BLADE SOLID FAN,A GOOD SHROUD WITH THE FAN IN IT ABOUT 1". TIMING AT 35TO 37 DEGREES ADVANCE,AND A 190 THERMOSTAT AND A 16 LB CAP.
THANKS.

ford5
Dirt Freak

Total posts: 221
posted February 05, 2002 08:03 PM
it probably has alot to do with the fact you can only get 60 laps on your rod brgs i'd be willing to bet

millerlt3
Dirt Forum Racer

Total posts: 95
posted February 05, 2002 08:14 PM
I have always been told that anything over 260 degrees while its running usually means your rings are warped and trashed so you might want to check that out also at 300 you might have a cracked or warped head. and sometimes a high volume water pump is not the answer to over heating because it does not allow the water to stay in the radiator long enough to cool down. I have some other ideas and comments on cooling if you would like to email me at millerlt3@yahoo.com, Ill explain them in detail.

dirttrackracer
Dirt Forum Racer

Total posts: 77
posted February 06, 2002 04:48 PM
Check the gauge,at 300 degrees you would be lucky to get 60 laps out of it.

DodgeBoy76
Dirt Full Roller

Total posts: 73
posted February 06, 2002 06:16 PM
I agree, we had the same problem. Our gauge would always peg out, and we did find that our heads were warped due to a rookie mistake with not locking the distributor out. But our gauge would always read well over 270 even after we found out the problem with the heads!! switched gauges, and presto 210 degrees at all times.

PEDDLER
Dirt Freak

Total posts: 227
posted February 06, 2002 07:33 PM
Also get a good carb man. Has a lot to do with heating.

The Peddler

new8
Dirt Full Roller

Total posts: 34
posted February 06, 2002 07:57 PM
quote:
Originally posted by DodgeBoy76:
I agree, we had the same problem. Our gauge would always peg out, and we did find that our heads were warped due to a rookie mistake with not locking the distributor out. But our gauge would always read well over 270 even after we found out the problem with the heads!! switched gauges, and presto 210 degrees at all times.

yes*** i would like to know what you mean when you said, locking the distributor out.
thanks

cut_n_up
Dirt Roller

Total posts: 20
posted February 06, 2002 10:07 PM
are you running reduction pulleys?

erik
Dirt Roller

Total posts: 5
posted February 06, 2002 10:13 PM
I would try running a 22# cap if the heads check out with methanal you should never see that kind of temp.My car hardly ever sees 200

bbracer17
Dirt Freak

Total posts: 252
posted February 07, 2002 08:41 PM
With a 16 lb cap the radiator should be completely empty by the time you reach 300 degrees.

Gene
Dirt Maniac

Total posts: 183
posted February 07, 2002 08:43 PM
At 300 degrees you would think the thing would smell like its burnning up! If there is no oder, and you're not steaming, I'd think the gauge is bad. Use your wife's oven temp gauage on the oil filter, it is usually close to the water temp. Are you burning the oil also?

uforacing51
Dirt Freak

Total posts: 240
posted February 07, 2002 11:24 PM
When I ran my modified, it had a 12.5 to 1 alchy engine with a corvette water pump and a 3 core aluminum radiator with a 22lb cap. I had trouble in cool weather getting it to start. I had to use gas until it was running then let the alchohol run in. Later in the season I had a head gasket go bad and my engine ran but did some strange things, some in the area of temps. Do a compression check on the motor first, if that doesn't show anything you may need to take the motor apart and have all your parts checked. but its the off season and you should be doing that anyway, right... right??? (I should mention that we did use a BG carb with 99 jets) All of the info above is good info. I have also had a guage tell me that I was overheating all of the time till I found out the guage was bad, stuck a new racing guage in and surprise!!! 200

[This message has been edited by uforacing51 (edited February 07, 2002).]

dirttrackracer
Dirt Forum Racer

Total posts: 77
posted February 09, 2002 05:49 PM
Remember science class when you talked about the boiling point of water(212 at sea level).All you have to do is take the sending unit out of the intake and stick in boiling water to see what it reads.Eliminate the easy things first.

LITTLEMAN
Dirt Maniac

Total posts: 130
posted February 10, 2002 12:24 PM
I'd use a 3/4 inch reducer in the thermostat first thing and what condition are your hoses in?one year i was having alot of problem keeping my temp down and i found out through pure luck my radiator upper hose was sucking shut nowadays i make sure the springs are not sliding down the hose and getting a weak spot.Also the belts can slip pulling that big of a fan and defeat the purpose of it causing all sort of heating problems.

sideways34
Dirt Full Roller

Total posts: 40
posted February 15, 2002 12:42 AM
My opinion on the subject is this. Get rid of the thermostat. Put in a 3/4 reducer. Put a 22-26 lbs cap on the rad. And run a 4 or 5 blade fan. I have all of this but I run a 5 blade carbon fiber composite fan on my mod. I also have a moroso aluminum water pump, with reduction pulleys. I don't sugest this but I don't run a shroud, and I run alky and my car never sees over 200. I have had a guage go bad on me and tell me I was at 260 and wasn't. Just my opinion.

[This message has been edited by sideways34 (edited February 15, 2002).]

bkap
Dirt Full Roller

Total posts: 61
posted February 18, 2002 01:18 PM
These are all good suggestons. I would add that you should make sure the radiator fins are not clogged. You can either take the radiator out and shake it front side down or use a garden hose (not car wash wand) and spray from the back to the front while it's in the car. This is a good practice on a regular basis, anyway. Also, make sure your hoses are not crimped. And I've had bad gauges in the past. It happens. Make sure you don't have a sending unit wire shorted out someplace.

DirtDobber
Dirt Full Roller

Total posts: 53
posted February 21, 2002 10:10 AM
At 300 deg you should be burning oil pretty bad.
Change temp gauge. You must have reliable tools to help you troubleshoot on the track and off.
If you are experiencing temp problems the most common issues are:
Clogged engine/Clogged radiator/collapsed/kinked hose (restricted water flow).
Exhaust getting into the water due to a cracked head or blown head gasket.
Stuck thermostat/incorrect thermostat. For you restrictor plate fans too small hole.
Bad water pump.
Incorrect water pump speed (too slow/too fast).
Radiator too thick. Note not same as too wide!?
Wrong pressure cap.
No shroud around fan. Improper fan positioning within shroud.
Bad fan design
Air in the cooling system. Find the high point and bleed it after every race.
Like dirttrackracer started science is Kool! The boiling point of water, the temperature at which the vapor pressure of a liquid equals the pressure on its surface. If the pressure of the liquid varies, the actual boiling point varies. For water it is 212 degrees Fahrenheit. That is water at sea level exposed to air. If we contain it within a pressurized system that boiling point is then raised. A very common myth that was brought up by a previous comment was to contain the water in the radiator a little longer possible for cooling time. K lets think this through a bit further. This is a closed pressurized system. If we slow the water down in the radiator that means we are going to slow down the water in the engine. Now you have a serious heat generator there creating hot spots around the cylinder walls. Fuel burning engines produce enormous amounts of heat; temperatures can reach up to 4,000 degrees F when the air-fuel mixture burns. However, normal operating temperature is about 2,000 degrees F. The cooling system removes about one-third of the heat produced in the combustion chamber. If we stop or slow the flow of water too much here then the water will vaporize causing gaseous pockets. If these gas pocket move to the water pump then it will just spin around cavitating itself not doing the work it was designed to do, move water. Temperatures here then begin to exponentially rise to the point of metallic breakage. Rings, pistons, cylinder walls and such. These temperatures are also greater than the breakdown or burnt value of oil. Save that for another discussion. Oil is a crucial part of cooling too.

AAGHEE my head hurts! Where did that come from? Oh yea its part of my ***. (job)

Result
Largest surface cooling area you can mange thickness is not always the answer as the efficacy of the subordinate rows are not as the fir and it is easier to move warm water the cold water.
Keep hoses in top shape
Check/calibrate gauges often
Do not restrict flow too much
Cold water warm oil!

Oh yea one more thing do you run a puke tank? If not you may be sucking in air as the machine cools.

Food for thought!

One part courage
Two parts nuts
Stir counter clockwise till fun!

Chad
Dirt Forum Racer

Total posts: 82
posted February 21, 2002 11:45 AM
This sounds stupid, but I've seen it happen on more than one occassion. Make sure the pitch on the fan is going the correct direction. Guys get in a hurry when they put on the fan, and I've seen them get the fan on backwards. This would definitely cause an overheating problem. No one mentioned so I thought I would.

modman97
Dirt Full Roller

Total posts: 45
posted February 21, 2002 01:22 PM
There is alot of good info on this site, thanks to some real knowledgeable racers.
I encountered this same problem myself a few years back as a rookie. (Overheating with an alcohol race engine.) Being totally green as a driver/owner, and not very mechanically inclined, I learned the hard and often expensive way. I ended up doing just about everything that was mentioned previously.
I was embarrassed to tell people what the solution ended up being. It was a plugged radiator. Just like someone on here mentioned. There was NO visible clay in the radiator but over time it had plugged form all the dust.
I had the carb rebuilt, new water pump,bigger fan etc.
My advice would be to always start with the simple and /or least expensive suggestions. Also, when I would throw a bunch of stuff at a problem at once, I never new exactly what the problem was. You then have spare stuff ,and dont know if its good or bad.
My guess- BAD GUAGE
Let us know the outcome!

dirtracer14
Dirt Freak

Total posts: 333
posted February 22, 2002 02:03 AM UIN: 23443678
One thing i found with a rad was that if it is allum and had a head gasket go bad it will swell the cores and not allow the water to be cooled as it flows threw. Take a look at the cores if they are swelled up in the center that would cause it to run hot. Just thought i would toss it out there!

pipes
Dirt Roller

Total posts: 17
posted February 22, 2002 07:35 PM
quote:
Originally posted by new8:
I WOULD LIKE TO KNOW HOW TO CURE MY COOLING PROBLEMS? FIRST OF ALL MY TEMP HITS 300 DEGREES. I HAVE A NEW 3 CORE COPPER RAD,A HIGH FLOW WATER PUMP,A 7 BLADE SOLID FAN,A GOOD SHROUD WITH THE FAN IN IT ABOUT 1". TIMING AT 35TO 37 DEGREES ADVANCE,AND A 190 THERMOSTAT AND A 16 LB CAP.
THANKS.

make sure you still have a spring in the bottom rad hose, use a 3/4inch or 7/8 restrictor in the stat housing instead of a t-stat, get rid of the 7 blade fan and use a 4 blade at speed the 7 blade acts as a wall and wont let air thru also keep a 22 psi cap cause you might need it
hope some of this helps

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