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Author Topic:   Running HOT!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
RCRacing #08
Member
posted August 23, 2003 11:27 AM
Okay, here is a question on over-heating.

If you ride around not pushing the car you run fine. Now if you run the car at 5800 to 6000, which is the normal rpm's that you run under green, then you start over-heating. So what would be the cause, the timing is correct.


fastrack1
Member
posted August 23, 2003 12:56 PM
possible cracked head in the exhaust seat are u losing water or temperature just climbing remove the header and see if u see a discolartion on one verses the rest if so bingo


RCRacing #08
Member
posted August 23, 2003 01:58 PM
no just climbing not losing water


2nd2none
Member
posted August 23, 2003 02:25 PM
could be your pulley's are wore out, especially the crank pulley, at higher rpm's if the pulley is wore it'll be slipping the belts. I had this problem last year!


jay116
Member
posted August 23, 2003 03:02 PM
RC 08 runs a serpentine belt
we could try a new belt but I think our culprit is in the heads. Any other ideas?

------------------
Jason Boivin
http://www.rcracing-team.com


wrenchjockey
Member
posted August 24, 2003 12:51 PM
Make sure your lower radiator hose has a spring inside, or it can collapse under the suction of the water pump. It will actually flatten the lower hose completely with no spring to keep it's shape.


RCRacing #08
Member
posted August 24, 2003 08:05 PM
I run springs in both hoses.


avila
Member
posted August 25, 2003 11:27 AM
Carb running too lean? What do the plugs look like? Broken water pump shaft.


ss99
Member
posted August 25, 2003 12:38 PM
Some things I would check - make sure the timing is not over advancing at high RPMs. It may show correct at 3000 or so, but it may continue to advance beyond that. Belts slipping, restrictor or thermostat too restrictive, air/fuel mix too lean, poorly designed fan shroud, worn out water pump.


FastEddy
Member
posted August 25, 2003 12:55 PM
Have you checked for any vacumn leaks? What about radiator flow? Is the water pump worn? Getting enough air? You could try an EGT to check temps at different rpm's.


GO 24
Member
posted August 25, 2003 02:05 PM
It's possible the water pump is cavitating at the higher rpms, I've seen this many times on stock or even cheaper alum pumps.


dirtracer7
Member
posted August 25, 2003 07:06 PM
Make sure your radiator is clean and the air is getting to the radiator.Ductwork on both sides .


ATL72
Member
posted August 27, 2003 06:51 PM
quote:
Originally posted by GO 24:
It's possible the water pump is cavitating at the higher rpms, I've seen this many times on stock or even cheaper alum pumps.

I also have the over heat issue and have done all the checks plus pressure test, 230 at 36 degree advance and 200 at 34 advance with TDC rechecked and centers correctly... WHat would cause the wtr. pump to cavitate???


ruggs66
Member
posted August 27, 2003 11:09 PM
what fan are you running?

I have had the best luck with the older 4 blade fans that came off off 60s & early 70s cars.

I was told some fans cool real well at low speeds & act like a piece of plywood at higher RPM.

just an idea....

jay116
Member
posted August 28, 2003 12:38 PM
yea we run an old 4 blade fan.
We have a friend that pits next to us who has been over heating all season. They bought a six blade flex fan and thought their problem was over. I tried to tell them that "that fan will not work at high RPM"
one its a flex and doesn't pull any air at speed and those blades become a wall stopping the air not moving it.
We think we figured out our problem. It was an air flow problem. Will find out if its fixed tomorow night.

------------------
Jason Boivin
http://www.rcracing-team.com


66jj
Member
posted August 28, 2003 04:06 PM
distilled water is good for around a 15-20 degree drop.



GO 24
Member
posted August 29, 2003 03:50 PM
I was told a stock pump obviously was not designed for high rpms and for lack of better technical words the propeller design causes the water to cavitate at the top of the pump---that comes from my engine builder after I tried a stock pump on my very 1st race motor years ago, switched to a good alum one and it cured the problem.
66jj is right on, I've seen 10 degrees just changing to distilled water.


race2j2000
Member
posted September 07, 2003 11:51 PM
i had similar problems and we move the fan closer to the radiator and the problem was gone ......we used an old ford spacer ...this might be somthing to look at ,just an idea


jay116
Member
posted September 08, 2003 06:22 AM
We have a new fan. Its a flex a lite six blade. Its plastic with the narrow blades.
We boxed in the front of the rad. And opened up the grill more. It will now pull a rag out of yout hand and stick it to the grill.
We had the week off so we dont know how well it works. Will find out on friday.
I also created a fan box and electic fan to hang on the grill to blow in air while sitting in the pits with the motor off.
Hope our hot problems are over.

------------------
Jason Boivin
http://www.rcracing-team.com


GO 24
Member
posted September 08, 2003 11:38 AM
I gotta disagree with ya on that fan Jason, I wish every circle track parts dealer would quit advertising that junk. The flex-a-lite fans do not work in racing applications period, their for street rods and I wouldn't even use them for that! A 4 blade steel fan is the only way to go, in my opinion anyway


jay116
Member
posted September 08, 2003 08:23 PM
24 I used to agree 100% with you.
BUT we keep overheating with the 4 blade steel fan. We will run this fan on Friday and if it still runs hot we will go back to the 4 blade but till then we have to try this fan. http://www.flex-a-lite.com/auto/400.htm
We are using the 18 incher.

------------------
Jason Boivin
http://www.rcracing-team.com


Dixon
Member
posted September 09, 2003 01:43 PM
66jj,

I can understand how using distilled water might drop your temps slightly, but at the same time it will lower your boiling point. Do you mix it with anything or just run it straight?

Bomber94
Member
posted September 09, 2003 08:14 PM
Had similar problems. Here's what I did.
1. Installed good shroud from junkyard.
2. Bought 6 bladed steel fan from Speedway Motors. Must fill shroud to within 1/2 in. This is not a flex fan.
3. Cut the shroud so that half of fan blade is sticking out behind.
4. The biggest improvement was installing a 21 lb radiator cap.
Never goes over 200 degrees


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