How do you cool your big block with a 22" radiator??

[65DODGE]

just a thought but make sure you dont have an air pocket in the cooling system it may need burbed get the air out of the system its worth a try anyways.

 

[Hemirunner]

Most cooling system problems seem to be a combination of things that aren't right. Check the cooling system pressure and make sure you have the correct pressure cap. Pressure raises the boiling point and without it, you will heat up quick. You need a decent radiator ( I use a factory 26" hemi radiator), a good shroud, the factory one will suffice. I run a factory fan (most flex fans move very little air and for the most part only work with a drag only car) with a clutch. (verify the clutch is good) You need good water flow and a working thermostat as well as a good state of tune. The fan should be lined up with the opening in the shroud, not jammed up against the radiator. You need plenty of airflow at idle and highway speeds and the engine needs tuned well to not generate heat at idle. Check simple things like the carb idle settings and timing at idle. If it has little to no timing at idle, that could be a big part of your problem. I cool a 9 second, big cube, pump gas hemi with a stock cooling system and no issues. Most electric fans (even duals) won't move much air and block more airflow than anything. They may be fine as an auxillary unit, but I've never had a need for one even going rounds and hot lapping.

 

[no462of12K]

if all else has failed go chemical--redline water wetter-drops the temp 10 to 16 degrees-won't harm h2o pump-flex fan with long spacer-works for my x( 440 /410 gears)

 

[wedgie]

I have absolutely no overheating problem in any weather with my '65 B body. Stock 1965 426 radiator, 496 inch stroker motor, 906 iron heads, hemi aluminum waterpump and housing. I have a stock type shroud and stock type fan. You must have another problem. Do you have an auxilliary trans cooler that may be blocking air flow? Mine did run warmer with the automatic trans than with my current 4 speed.

 

[Cranky]

[FONT=arial,arial,helvetica]A 50/50 mixture of water and ethylene glycol antifreeze in the cooling system will boil at 225 degrees if the cap is open but as long as the system is sealed and holds pressure, a radiator cap rated at 15 psi will increase the boiling temperature of a 50/50 coolant blend up to 265 degrees. If the concentration of antifreeze to water is upped to 70/30 (the maximum recommended), the boiling temperature under 15 psi of pressure goes up to 276 degrees but I've always heard that straight water cools better than EG/W mix.

One thing most don't think about is [/FONT][FONT=arial,arial,helvetica]poor heat conductivity inside the engine because of accumulated deposits in the water jackets. IF the block and heads are not cleaned when rebuilt, you can have this problem and the old style caustic vatting does not remove rust accumulation and sometimes the newer pressure wash vats don't either. I hope this isn't your problem but if all else fails, you might have to address it. Years ago I decided to dig into an old set of 906 heads and was surprised at all the scale that came out AFTER they were 'cleaned' for rebuilding at a shop.

There's a lot of info on the net and I think this site is good but the more you know, the better off you are. http://www.arrowheadradiator.com/overheating_causes_and_cures.htm
I didn't know about the boiling point that 50/50 coolant offered but knew about the rust/crud buildup in the block and heads. Also, you didn't say how much your engine was bored iirc....? Do you know exactly how much it was bored? I got an engine in once that was having heating problems that was supposed to be .030 but it turned out the shop that did it took it to .060. Did you have the block sonic tested before rebuilding? This can also be a problem. Core shift is another reason why an engine should be sonic tested.

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