The Ford Barn

drolston · 08-17-2019, 10:02 PM

Summary: 284 inch 59A/B with Offy 425 heads, mild Schneider 248f cam and Champion aluminum radiator with 7lb cap. Block was cleaned by flathead expert at overhaul. With summer temperatures in the 90's, it would overheat badly at idle in a few minutes. Also overheated badly at highway speeds over 60. 220+ degrees. Here is what did not work:
- water wetter additive; no effect
- spacer to get fan closer (1") to radiator; no help
- shroud and baffles to prevent air from going around radiator; no help
- Dennis Carpenter water pumps; helped a little at idle - took longer to boil
- advanced timing; no help
- richer jets (.045 to .047); helped a little at highway speeds
- removed 170 degree thermostats; helped a little at idle and at speed.
- but, still running way too hot!

With plenty of water flow and plenty of air flow, and all the other little factors ruled out, that left the conclusion that there was just not enough radiator. The car came with a 01T 122" wheelbase truck radiator in it. That should have been a clue. I cleaned it and sealed it and put it back in. It has 462 square inches versus 399 of the Champion. That is 16% greater, plus the truck radiator is 5/8'" thicker, for a volume increase of over 50%.

Drove it to my 60th High School reunion today with temperature in low 90's. It idled for 20 minutes while classmates admired my latest hot rod, and the temperature never got to 200. At 55 it runs at 170 degrees, and at 65 to 70 it got up to 195 on a long grade. I declare victory! The cross-country road trip plan is back on.

08-17-2019, 10:02 PM	#1
drolston Senior Member Join Date: Jun 2014 Location: Williamsburg, VA Posts: 1,628	Finally got it to not overheat! Summary: 284 inch 59A/B with Offy 425 heads, mild Schneider 248f cam and Champion aluminum radiator with 7lb cap. Block was cleaned by flathead expert at overhaul. With summer temperatures in the 90's, it would overheat badly at idle in a few minutes. Also overheated badly at highway speeds over 60. 220+ degrees. Here is what did not work: - water wetter additive; no effect - spacer to get fan closer (1") to radiator; no help - shroud and baffles to prevent air from going around radiator; no help - Dennis Carpenter water pumps; helped a little at idle - took longer to boil - advanced timing; no help - richer jets (.045 to .047); helped a little at highway speeds - removed 170 degree thermostats; helped a little at idle and at speed. - but, still running way too hot! With plenty of water flow and plenty of air flow, and all the other little factors ruled out, that left the conclusion that there was just not enough radiator. The car came with a 01T 122" wheelbase truck radiator in it. That should have been a clue. I cleaned it and sealed it and put it back in. It has 462 square inches versus 399 of the Champion. That is 16% greater, plus the truck radiator is 5/8'" thicker, for a volume increase of over 50%. Drove it to my 60th High School reunion today with temperature in low 90's. It idled for 20 minutes while classmates admired my latest hot rod, and the temperature never got to 200. At 55 it runs at 170 degrees, and at 65 to 70 it got up to 195 on a long grade. I declare victory! The cross-country road trip plan is back on.