Technical Radiator cap on 8ba

What type of radiator cap do you 8ba guys run? I have a Walker radiator and currently running a 16 lbs. cap. Heard both ways that you should run lower lbs and also heard higher. Thanks.

 

I ran a 7 lb on my Walker without any issues.

 

16 sounds high to me, but it mainly depends on the radiator. I would check with Walker and see what they say.

 

Honest Charlie told me Walker calls for 15 lbs. But Speedway motors said 7lbs.

 

7 lbs, deep reach.
No need for anything stronger than that, earlier 8BAs had 3 lb caps.

 

At that point I guess it depends on how hot you are wanting to run it. All the pressure cap is doing is upping the temperature at which the water boils. Unless it is overheating (which should be address with other than a higher pressure cap) why run a high pressure cap?

 

Unless you have a serious cooling problem there is no reason for you to run such a high pressure cap at sea level. I live at 8000 ft. al***ude and have no boiling problems with a 7 lb. cap on my blown 8BA. For what it is worth water up here boils right at 198 degrees and with the 7 lb. cap the boiling point is raised to about 222 degrees which is comfortable margin in my case.

In your case a 16 lb. system would give you a boiling point of about 250 degrees if it ever built to a pressure that high.

 

Another consideration for the flathead is water leaking past the shaft seals if the pressure is too high. original fh's weren't pressurized.

 

I run a 4 # cap on my 8BA and AB motors, stock radiators.

 

Of greater concern is the heater (if equipped).
The Walker will handle 16#, the water pumps probably have been replaced with good aftermarket items, so they will do.
If you are using an original heater, I would limit the pressure to 7#.

 

I spoke to Walker about the exact topic recently. Their tech support told me to go no higher than 7lb with a flathead. The radiator will take the 16lb their specs call for but the motor may not.

 

Good info here, i do have new pumps, no heater, although will most likely swap it out for 7lbs cap. Thanks.

 

I run a 4 lb cap on mine and have for almost 3 years now.

 

JFYI, Ford used a 7 lb cap for automatic transmission equipped ('51) cars, while std. trans 8BA cars kept the 4 lb cap, according to the "green" book.

 

On my 8BA flatty I have a Walker Cobra radiator with a 10 lb. cap I bought from Walker. Being doing that since 1999. No problems. But, make sure your hoses are double clamped.

 

4 lbs No need for more!