TEMP too high.

[Don Becker]

What should I do to get my engine temp down?

If I run the car over 5000 rpm is really gets too hot. It will keep going up until infinity. I do have a restrictor, old cut out thermostat. Should I take that out or restrict it more?

Is it the pulleys or pump?

It is a merlyn 17 which has vents out behind the radiator. I am not using the frame tubes, but aluminium external tubes.

[DKRock]

Could you provide a little history? Is the car new to you? Has it always done this? Any recent changes? Check to make sure no hoses are or could be partially crimped against frame tubes or could suck shut on the supply side. Are the bleeds open and moving water when the engine's running?

Just guessing.

[size="1"][ September 09, 2002, 01:15 PM: Message edited by: Doug Black ][/size]

[LenFC11]

Joe,

Have you had the rad down to the radshop for a good boil out? while there you can inquire if the rad has had a recore or is still running the old style heat exchanger. I recently acquired a Reynard which had been a chronic overheater, a trip to the radshop confirmed 1982 cores. He matched the core thickness to the header tanks (about 3/8 thicker) and it has run perfect all summer. My 11A needed a good cleanout on the rad as well to operate efficiently.

[timmy]

Could be many things...

At 5000 rpm, is the car in gear and moving, or parked in the paddock... [img]smile.gif[/img] just kidding. But airflow to the rad(s) is a consideration.

Cracked head?
Bad head gasket?
Too much spark advance?
Too much anti-freeze?

Back to the cooling system...

I once put a brand new rebuild into a car and immediately had heating problems. Went crazy chasing things. Even ran a water hose through the radiators to make sure they weren't clogged.

Turns out the block had been sitting a while before the rebuild. The water jackets had not been shot peened. When we started the new motor the rust flakes fell off and clogged about 75% of the radiators. A water hose would flow through them fine, but they had lost 75% of their cooling surface. You could look into the inlets and not see the blockage. We didn't spot it until the tanks were taken off the radiators.

Turns out this happens to a lot of engines that sit for a long time...

Also, check for worn out water pump impeller blades. It won't be the first time.

I'm sure you have tossed the thermostat by now...

[Hvonert]

If it is a crossflow like my Mk11A then it is possable you are trapping air in the upper right hand corner of the rad. tank. (water is traveling on drivers left forward to upper inlet then across rad. to lower outlet).
If this is your set up are you running a bleed hose?
I soldered a 3/8" 90* nipple to the upper right corner of the tank, then ran a 3/8 hose back to the water pump inlet were the rad. hose clamps to. (there is a boss on the top. It may be drill and tapped or not.
This should pull the trapped air out of the rad.
I think :-0

Hope this helps,
Chris

BTW how hot is to hot????

[size="1"][ September 09, 2002, 04:31 PM: Message edited by: Chris Campbell ][/size]

[Jay Elardo]

Don’t for get the radiator cap. I had one go south on me in my Winklemann. Car cooled fine until the August and September.

Mark

[Rick Brannon]

Not to beat a dead horse, but check the gage. Pull the sender out and put it in water just starting to boil.

[Don Becker]

I do not have a bleeder, although my wallet will be.

I never had the rad cleaned.

How hot is hot, it went over 230. But I got third place, on the last corner of the last lap.

[DKRock]

Bad head gaskets do not necessarily show up in either a leak down or a cooling system pressure check. I've chased some of these and they can be a bear to determine without taking the head off and reading the gasket. There used to be a kit for detecting carbon monoxide in the cooling system. Big help. Maybe someone remembers a source for this kit. First hint is the amount of water you'll have to replace each session. Also, some leaks only push water at a load with wide open throttle (max cylinder pressure). Therefore, just because the CO test is ok idling in the paddock does not mean you're out of the woods. Here's hoping it's not a head gasket or cracked head!

[zcar72]

I just went through that with Karen's Lola. It had not been raced for 9 years. The first time out it was good on Saturday and got a bit hot Sunday and had to keep it below 5500 to avoid 115 degrees C. It was worse on the next test day. I had the radiator taken apart and rodded out. Got about thirty pounds of flakes out of it. The next test day at Willowsprings it was 98 degrees F air temp and the car never went over 95 degrees C. [img]tongue.gif[/img]

[Don Becker]

I restored the whole car except for the radiator. Maybe a cleaning is all it needs.