Technical 1930AA Rad with a 241Hemi

What I was wondering has anyone else done this and if so can you tell me how it has worked for you.
I just want to put a cap on the stock rad and run it, having trouble getting a cap to seal. Got speedways 30-31 cap and it leaks, so am thinking about putting in another rubber gasket, any help would greatly be appreciated

 

anyone with info?

 

Probably wrong, but I thought the early Ford's had unpressurized cooling systems.
-Dave

 

Unpressurized, sure; but the cap sealed, the overflow tube was internal to the filler opening.

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If it leaks the radiator is to full.

 

You see what Sunbeam is telling you?It's not supposed to seal. You know how water expands into the recovery tank as your stocker warms up? Water in an A expands also. It has to go somewhere. Out at the cap or out through the weakest seam.

 

While it may be news to people unfamiliar with stock early Ford (and other) radiators; as I said in post 4, the caps are supposed to seal. The overflow is in the neck of the radiator, exits the upper tank, and runs to the bottom of the radiator. This are borrowed pictures of a deuce radiator; but other than the style cap; the idea is the same.

 

Is your vent tube open? Seems as though water would run out of there rather than the cap.

 

I have just air tested the rad and bubbles came out of the cap and overflow vent tube, when submerged. I know of 1 person who uses a stock 30 rad with a 302 and he said it overflowed once

 

We used stock A radiators with sbc engines quite a few times with no problem. Aren't the old hemis supposed to run cooler anyway.

 

I'm going to ***ume you have not had an actual heat issue, just a water loss. If that's the case I'd let it find it's own water level and then see if it want's to get hot or not. Make sure you have a working Temp gauge and go drive it. (carry a jug of water with ya first time out)
The Wizzard

 

The open overflow system finds it's own level and holds it if you don't have a problem elsewhere. You fill it once, and it will blow out the expansion water as the engine reaches normal heat. The resulting level holds as long as everything is normal, and any attempt to fill the thing above its chosen level will be blown right out.
Ford had some troubles with cap leakage...obviously the seal was less than perfect...caused by the pump throwing water at the cap too hard, if I remember correctly. There is a major bulletin on this in the Model A Service bulletins.
I forget the details but a shielding baffle in the cap opening and a shift in the overflow tube were the official solution. Read the bulletin.
I've had some thoughts a slight pressurization and maintaining level in these that I might try someday:
Shim the cap gasket til it seals.
Run a line from the overflow tube to an overflow tank.
Using a T fitting build a pressurization/recovery widget...T fitting holds 2 pressure valves, probably streetrod type brakeline valves...one would be OUT, sprung for light pressure like 3-5 pounds. The other would be IN for recovery and would be very lightly sprung. This would allow pressure to hold while running, and when the pressure cools down water will overcome the backflow valve and the cooling radiator will draw its water back in.
I think.

 

The hemi wants a pressurized fuel system. In most cases today that means a new core and a different filler neck. Model As were not pressurized, but they also did not have much of a pump.

Best bet it take the radiator to a reputable radiator shop and have it converted for pressure. a couple of hundred dollars down the road and you are down the road.