Ron Pope Motorsports                California Custom Roadsters               

Hot and bothered in Portland


New Member
I finally fired up my project last week- TOO HOT ! I had to shut it down after the temp started rising past 210*F. The radiator is one of Bill Isley's (Wellbaum's) trick "T" units with an electric fan hidden inside between two cores. The engine is a Chevy 355 with some goodies (Comp Cams 274 advertised duration hydralic flat tappet, Holley 780 cfm 4160-3310 list- RPM Air Gap, yada yada yada). I was able to break in the cam by putting a bigass box fan in front of the rad. I'm running a 7lb. cap (any more and the top tank will bulge out- so I'm told). I'm also running a second 7lb. cap up at the high point of the system- a special water outlet with ports for senders and a Moroso air bleed (Jeg's). I know a new engine will run hot- but I don't want to cook it either. The pump is a Speedway "high volume" unit. Could it be overpowering the 7lb. cap?- It keeps puking out the upper overflow. I'm running straight water with water-wetter and a little EG coolant to start. Anybody running Evan's NPG+ coolant? THANKS !
I had this problem when I first got mine on the road. I fought it for a year or so then I drained the system, added a bigger late model modified fan I got from Speedway and put in a new thermostat. The fan and thermostat helped but I think the real problem might have been air in the cooling system not allowing for a complete fill. When it all got sorted out I could start the car and let it idle all day and it would run out of gas before it ever got hot.
If you have just filled the system then I would definetely agree that its air in the system. When I first got mine together It wanted to run hot and puke fluid. It took a little time but once I got all the air out its been 180 to 190 degrees.

I run that very same radiator but only one 7 lbs cap on a high compression 327 with tunnel ram and two 500 CFM carbs and that radiator has worked perfectly even over in eastern Washington with temps over 100... I suspect you have air in the system, or something else going on... but that's good news cause I know how much that radiator costs! :eek:

Here is mine...

Thank you all for your responses to my cooling problem! How do I get all the air out of my system? I did a slow fill while having a intake plug removed. I also used the pushbutton air bleed up at the water outlet while the engine was running. Yet after I shut it down and let it cool, I open the upper cap (at the water outlet), and theres air down to the stat almost (and air in the upper rad hose). Lumen Al: I followed your build at and found it very interesting- my T is very similar but I started years ago. I got to know Bill Isley down in Eugene as he was building my radiator- a real hotrodder and of course a very talented craftsman- he was working on a center door T project when he died suddenly. I need my wife to help me post pictures here! Or one of my kids!
You leave the upper cap off let it warm up (while idleing) and keep adding water. Well, thats how it has worked for me. An overflow tank would be a good investment.
I had the same problem as most people do when the engine sits higher than the rad.After three boil overs a buddy came over with his Snap On preassure fill system.Go to Snap Ons web sight and youll see it no muss no fuss and the car now rarely gets to 180 even in cruise traffic.
hotrodman said:
... I got to know Bill Isley down in Eugene as he was building my radiator- a real hotrodder and of course a very talented craftsman- he was working on a center door T project when he died suddenly.

Bill Isley... Wellbaum Brass


Yep, Bill's sudden passing was very sad indeed... for people that have not seen some of his work... here ya go!


this is how i do it i drill a hole in the thermostat about 1/16. take the upper rad hose off the thermostat housing leaving your rad cap on hold the hose up above the rad and engine add your antifreze till it comes out of the thermostat housing what this does is fill from the bottom up and will push the air out the hole in the thermostat run the engine till the thermostat opens let it cool add antifreze if needed to overflow tank.

     Ron Pope Motorsports                Advertise with Us!