Overheading problems - WHY?

If you lasered the radiator (tank) and it is 210 degrees, the coolant will be 210 or close to it.

 

Sounds Like You Might Be Getting Some Air In Your System.
You Might Try Some Water Wetter And See The Results.also Could Be A Faulty Radiator Cap.

 

I think I might agree.

 

does the car have a hood and hood sides, or is the engine exposed ?
a fan shroud is very important, flex fans are junk. sounds to me like the thermostat is stuck closed.
that this is getting way too hot.

 

'65 Mustang radiators come in 2,3 and 4 core. Which do you have? I believe 2 core were strictly for 6 cylinders cars.

 

two inches away from radiator and no shroud.
I'm suprised you don't have old faithful erupting regularly.
If you can't have a shroud, it needs to be REAL close.
Get a shroud on that bugger and move some air through it.
I'm guessing that when you put a hose on it, it dries uniformly and cools down like nobody's business.

 

I always cut the thermostat apart, so it only slows the flow down, and can't be stuck. might take an extra 5 minutes to warm up, but it doesn't "fail". and a shroud helps a ton. get some 3" wide sheet metal, wrap it around the fan, make some tabs for mounts and see what happens.

 

Whether flex fans are junk or not, it depends on what type you have.

I run a 17" Hayden stainless flex fan with wide blades on my 32 with 462" Buick engine.
The fan hangs pretty low, but the engine runs cool.

I'm guessing that the narrow fiberglass fan blades don't do as well, but I do see cars running them and not having a problem so I'd guess that the overheating may not be due to a flex fan, but to how the engine is set up and is the radiator suitably sized and is it flowing well internally as well as having proper airflow through it.

I've run with and without a shroud and there's not too much difference.

The car does have hood sides and a top and that seems to help, but I've run without hood sides with and without a shroud and it still runs cool.

The big secret in my case - and a whole lot of other cases I've been involved with - is having a vacuum advance distributor and selecting the vacuum source to full time vacuum and not ported vacuum.

When I had the vac advance selected to ported vacuum the car got hot in about five minutes in summertime traffic.
After swapping to manifold vacuum, no more cooling problems....

 

I had some of the same issues on my v8 swap. it never boiled over but it was dam close. I bought a better fan, and i shrouded it. made all the difference in the world. the deal with the thermostats is a first thing i would look into. I have had them go bad like this even if they were new. I now drill a small by pass hole in them before installation just to get some flow until I can get it replaced. Much better than a total lock up.

 

Note as well the air in the cooling system comments.

My 32 only ended up with an air bubble one time.
I cracked the sending bulb fitting open a touch until only coolant came out.

The air bubble bit can be self-curing if you drill one 1/8" hole in the thermostat flange so the air and then coolant can pass through.
It doesn't affect cooling in hot or cold weather.

One's enough though, I drilled two holes initially and it took four miles of 40 mph cruising to get the coolant up to 180 degrees.

With one hole it only takes one mile at the same speed.

Both times, at an ambient temperature of 16 degrees F.

 

Car doesnt have hood or sides.

I have replaced the thermostat, drilled holes in it, and taken it out. Doesnt change anything.

I have a new 3 row mustang radiator.

I am starting to think that the radiator would be the only thing that could bring it down 50 degrees.

Two row 1 in tubes or 4 row brass/cooper. What do you think?

 

<TABLE id=HB_Mail_Container height="100%" cellSpacing=0 cellPadding=0 width="100%" border=0 UNSELECTABLE="on"><TBODY><TR height="100%" width="100%" UNSELECTABLE="on"><TD id=HB_Focus_Element vAlign=top width="100%" background="" height=250 UNSELECTABLE="off">I had that problemand this is what we did, we pulled the radiator had it boiled out. We removed the FLEX fan and enclosed the shroud, no more problem. The clutch fan and shroud plus boil out fixed the problem. Quite frankly the flex fan is a piece of crap don't use one. Rags
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Other than pulley diameters, you've covered it.

Any chance you somehow got a high flow water pump for a late model with serpentine, and it's reverse rotation?

 

My setup sounds very similar to yours,Mustang 3 core ,15 inch aluminum fan for clearance,283 stock water pump, fan is right up to radiator. No hood etc. 180 stat. Lower hose is one of those bendable stainless deals.
(DTBD mentiond lower hose restriction) It sounds like that could be an issue. I dont run over 190 even in 100+ weather.

 

Check your Cap,make a shroud-eveery bit of air going past your rad is wasted engine power,you are stiring the outside air nothing more. You need a good thermostat-1 hole nothing more.pull yoiur radiator checkit for blockage.if nothing works- get two electric fans it aint cool but neither is walking home.

 

If your thinkin about replacing the the radiator, I have aluminum radiators in both my Model A and our Anglia. Neither of them overheat.

I was wondering what kind of high flow water pump you have? A 'Flow Kooler' type with the plate on the impeller, or something else? It's possible to get one that's for a serpentine setup (as mentioned before). Could it be flowing the water too fast? I always understood that problem to exibit itself as boiling over while the temps are still low, but you've tried everything else.

 

Make sure you don't have a water pump for a serpentine belt system on there!

The serpentine pumps are made for a reverse rotation at the blades. Plays hell with trying to cool a motor. And don't ask how I know this!


jerry

 

Lower hose is not blocked. It has a wire in it.
Pump is not a reverse flow model.

Scott's set up that is very similar to mine and his works.

Guess I will start with a new radiator. What do you think aluminum 2 -1" tubes or 4 row brass???

 

I have read/heard that to fast of a flow can be just as bad as to slow. Coolant does not have time to lose its heat before going back into engine.

 

Just an odball shot... Did your intake gaskets have blocks for the coolant passages? Maybe put them in with the blocks to the front when they should have went to the back? I know I did that on my daily with a 350 not paying attention (I wish I still had that truck....) and it over heated to about 230-240 no cure... Took it apart to see I put the gaskets in wrong (was doing the job in like 30 degree weather outside in the wonderful windy city....) Intake gaskets are cheap, give it a check... the coolant blocks should be in the back.

 

Bought a PRC aluminum radiator -$420 and put a SPAL electric fan $100 on it. No overheating problems now.

Thanks for your help

 

CAn you tell which one really fixed it? Or does it take both? Does fan ever come on while driving?