Overheating question

[racerkrp1]

Mid seventies camaro street stock. All steel sbc.. New Triple pass radiator, New racing 22lb cap. New stewart stg 3 water pump. 1-1 pulleys GM 4 blade fan. Good shroud ect.. Timing at 34 degrees. Plug color fine. The problem is No heating problem until about 10 laps or more in the feature, Then the temp starts climbing to about 250 and pushes water out. This happens in warm and cool weather. I have pressure tested the engine no leaks. I was about to give up until last week I got in a little altercation on the track and my hood got bowed up in the middle and my car's temp went right down. The nose was still the same, nothing clogged with plenty of air to radiator. I am thinking that I am pulling too much hot air from my radiator and going right down the air filter into the engine as my hood is solid and the air cleaner is under the hood. Any other ideas? Next time out the air cleaner will be out of the hood for something to try. Thanks in advanced for your thoughts..

[rubbinsracin]

i would put my paycheck on it that the problem is the triple pass radiator. get rid of it and go to a double or single. also, i would get a heavier lb cap. we run the 28-32lb cap, double pass by afco, a speedway waterpump with no problems.

the triple pass takes to much pressure for the RPM and the cap that you are running. just do a quick search for overheating and you will realize that the triple pass radiators are for the cup boys.

[racerkrp1]

Started out with a single pass radiator, Done the same thing. Also had a speedway alum. pump on at the start of the season, same thing. Also the cap is a new stewart and it doesn't start to push water out till over 250 degrees.

[Egoracing]

Go to Stewarts site, He does not like tripple or double pass.
Are you running a T stat or anything in the housing?

[rubbinsracin]

Ego, I disagree with you on the double pass. there is nothing wrong with a double pass. just need to have a good pump to push the water and a 28-32lb cap. the double pass takes more pressure than the single pass. you will more than likely need the stronger cap.

I agree with ego that the next question is, do you have any type of restrictor or any type of t-stat in there? if so....get rid of it.

[parrot69777]

If your hood bowed up and your temp went down......it's telling me you don't have adequte air flow through the front of your car.....keeping all the heat in the engine compartment. If you can't get the outside heat away from the engine while your racing....the radiator isn't going to cool very well either.

[usafracer]

I had the same problem with a Camaro that I ran. I had to pull the inner fenders. So the air had a place to escape the engine compartment.

[racerkrp1]

I don't have any restrictor or stat. No fenderwells either. I guess we will see if putting the air cleaner out the hood helps this weekend. Thanks for all the input.

[Graff Spee]

I don't think that this would apply to you but make sure that the engine is at a 5 degree downward angle from front to back. If you don't do this you will have oil windage problems that can increase heat very quickly. i like the single pass radiator in all cars I race. Never had a problem.

[racerm146]

Definately an air flow issue. Make sure the hot air is able to escape from under the hood.

[Egoracing]

Ego, I disagree with you on the double pass. there is nothing wrong with a double pass. just need to have a good pump to push the water and a 28-32lb cap. the double pass takes more pressure than the single pass. you will more than likely need the stronger cap.

I agree with ego that the next question is, do you have any type of restrictor or any type of t-stat in there? if so....get rid of it.

I did not say anything either way, I said Stewarts did not like them. We tried a double and tripple and ended up with a single pass in everything from a crate up to the super motor.

[Egoracing]

I guess we will see if putting the air cleaner out the hood helps this weekend.

Air coming into the carb has VERY little to do with engine temp BUT you are loosing HP. For every 10 degrees of air going in you are loosing 1% of your HP. If you have a 400hp engine, it is 100 degrees outside air temp and your racing with the air cleaner breathing 250 degree under hood air your engine is down over 60hp.

The bow in the hood let air out which allowed air to flow. What you need to do is push the front of the wheel well opening out and the rear closest to the door in. This will create a low pressure area at the wheel well opening and it will pull the air from under the hood. You can see this on Dire late modes and even Nascar cars bey they have rules to how much they are allowed to do it.