41 Ford Radiator

[41Fordor]

I'm ready to bite the bullet and replace my radiator for overheating at highway speed. I see Griffin "39-41" aluminum and Walker lists different part numbers for 39-40 and 41. Is the 39-40 interchangeable with stock 41?

I know aluminum isn't original, but I need a reliable radiator for driving. Is Griffin aluminum or Walker Z series better?

Thanks!

[41LjH]

I believe the difference is the location of the filler cap. The 40 (39-40?) is on the driver's side and the 41 is in the center. I'm sure about the Pick ups and it's probably the same for the cars.

[G.M.]

If your original radiator is in good condition just have Skip rebuild your pumps and get almost twice the flow through the radiator. I drive at 65 to 75 MPH for 10 or 12 hours at 95 degree outside temperatures and it runs at 170. Skip@fordsrus.com for info. G.M.

[41Fordor]

Thanks GM, already done. My 221 is bored out to 239 with Isky 77-B but otherwise totally stock with 500 miles on rebuild. So far I've tried: my original radiator recored; Skips pumps and distributor rebuilt (and retimed by him after I messed with the advance); 94 jetted up to 51 which should be way too rich for this altitude; wires in lower hoses to prevent collapse; Gadgiteer's thermostats in upper hoses, but it overheats even without thermostats; Best graphtite head gaskets even though no leaks were found on pressure testing; new muffler just to make sure it wasn't plugged.

The temp gradually climbs at 55 mph to 205-210 degrees with plenty of air moving through the radiator. I can't think of anything else it could be

[V12Bill]

May overheat without thermostats because there is no restriction and the water flows too fast thru the core. When you used thermostats did you test them to see if they opened at the proper temp?

[nospartsman]

My local radiator repair shop (who are street rodders, flathead too) say the an aluminum radiator will cool 40% better than copper/brass. The 1941 Ford stock radiator is dimensionally a larger radiator than a 1939 Dlx, 1940 radiator. I have had several 1940 Ford cars with 1941 radiators in them, the tank likes to bump the hood on Dlx, fit is close. If you are ordering a new radiator, specify for a 1941 Ford. American Parts

[G.M.]

No Bill the water don't go through the radiator to fast. 41 make sure the fan belt is tight enough, 1/2" play. You could have a compression leak and do you fill the radiator up into the neck? G.M.

[Straightpipes]

I've got a 41 radiator in the barn. Don't know where you are but you could try it. Also, Is yours a split core?? Take temps off both sides of the block maybe you can pin it down.