34 ford running hot. Advise???

[yankee mike]

34 ford. Stock car 100%. Starts and idles beautiful. On a 55 degree day it overheats after about 10 minutes of idling. Engine rebuilt, checked water pumps and are ok. Drained radiator and fluid was clean. Any ideas???

[petehoovie]

How are you measuring the engine temperature? Is it boiling over? Why are you idling it for 10 minutes?

[WestCoast]

most common problem is a plugged radiator, an infra red heat gun can tell you if that is the problem, if the radiator is hot at the top and cold at the bottom, or even luke warm, restritcked water flow in the radiator, you can use your hand if no heat gun is available, put your hand on top of the out side of the radiator fins, if top is hot and bottom is cold plugged radiator, it should be hot at the top and fairly warm at the bottom, slow timing, cracked head or block, bad head gasket, check for water in the oil, bubbles in the radiator, a compression check will determine what is wrong, a weak flowing water pump or carb running to lean, or even the engine is idling to slow to recirculate the water thru the engine and radiator, take your pick, just check one thing at a time till you find the problem, my guess its the radiator, and as a side note, there is not a radiator cleaner sold in parts houses that work, save your money. and I forgot to say a bad temp gauge

[yankee mike]

Used the infra gun. Also used a thermometer dual temp read hot at 190. Above hot at 200 and then boiled over after that. Had it idled up a little around 900 rpm. Car has been sitting up about 10 years. Previous owner (friend)!said it never ran hot before. Ordered new drake pumps and going to check for a head gasket leak first. Than I guess if not that the radiator will be the next thing

[jetmek]

original aluminum heads? corrosion never sleeps....

[Straightpipes]

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If it was setting for ten years I would pull the heads and flush the bock and radiator. Heads are probably full of crap especially aluminey ones like guru jet me sez.

[yankee mike]

Yes aluminum heads. Looked like a little corrosion barnacles in there. Not much though.

[bobH]

Does this all imply that there is, somewhere, somehow, a stock 34 that does NOT boil, with several minutes of idling??

[yankee mike]

This is my first 34 so I don't really know the ins and outs with them. I've always had 32's. So is this common for a 34. I know flatheads have the reputation to run hot but I've never had one run over 195 I've had stock to Ardun powered

[JSeery]

The problem can be from several sources.

Junk in the block, casting sand, casting wire, corrosion, etc.

Partially plugged radiator.

Poor preforming water pumps.

These are a few of the more common issues.

[Strick]

engine rebuilt? new water pumps? clean unrestricted radiator? air pocket in the cooling system???

[JSeery]

Originally Posted by Strick

engine rebuilt? new water pumps? clean unrestricted radiator? air pocket in the cooling system???

Could be air pockets, but rebuilt does not mean that the casting core material was cleaned out of the block. My current block had been through several rebuilds and it was hard to believe the amount of junk that came out of the water jackets when cleaned specifically to remove the core sand and wire.

[Terry,OH]

There are many flatheads that do not overheat at idle. I can't get my 21 stud over 140 unless I install thermostats. Also check the distributor timing make sure the mechanical advance is working properly and not stuck and the vacuum brake piston for the advance is free to move.

[A bones]

Originally Posted by WestCoast

most common problem is a plugged radiator, an infra red heat gun can tell you if that is the problem, if the radiator is hot at the top and cold at the bottom, or even luke warm, restritcked water flow in the radiator, you can use your hand if no heat gun is available, put your hand on top of the out side of the radiator fins, if top is hot and bottom is cold plugged radiator, it should be hot at the top and fairly warm at the bottom, slow timing, cracked head or block, bad head gasket, check for water in the oil, bubbles in the radiator, a compression check will determine what is wrong, a weak flowing water pump or carb running to lean, or even the engine is idling to slow to recirculate the water thru the engine and radiator, take your pick, just check one thing at a time till you find the problem, my guess its the radiator, and as a side note, there is not a radiator cleaner sold in parts houses that work, save your money. and I forgot to say a bad temp gauge

I'm saving this, Thank you.

[rockfla]

To JSeery's point
A Friend here in town specializes in Flatheads, I've seen several flat heads he's done, as Jseery said, been rebuilt at least once, if not more and get a Folger's 16oz coffee can worth of sand, scale and gunk out of a block that had been cleaned before.

[FlatheadTed]

If you still have a relatively full radiator when this happens its likely a plugged Radiator ,as others have said .Its Air flow water flow verses thermo conductivity . there are a few I did it fixes that you can experiment with you can add a over flow tank with a 3to 4 1lb cap, or a valve or you could add high flow pumps that will force more water through ,or you could add a shroud that will suck more air. or get the Radiator rodded out . Ted

[Chris]

I agree, I'd guess radiator

[Ken Bull]

When my 21 Stud V8 was started after after more than a decade of sleep, I found out the CARB. WAS RUNNING too rich & flooding-- besides water steaming its way out of the radiator after 10 or so min. With idle at approx 700-750 RPM. Rebuild of carb with Daytona float valve-cured flooding & only filling the radiator about 1 1/2" over the tubes Cured the hot water loss & turns out to be the level the cooling system can live with without a overflow. Likes to run hot -190 0r less on the road around town in Florida.

PS Radiator was recored,Water Pumps & Coil Rebuilt by Skip & heads checked before start up.

[GSCOV]

check timing