Spinning the water pump faster?

Spinning the water pump faster?

I think you may be right 1968FormulaS340,

I found out about the hot air recirculation when I put the second aluminum radiator in my car. It was sitting in the driveway with the hood off and not goining above 170. I thought that the first aluminum radiator that I put in was bad and that this new on had cured my problem. Well I left the car running and put the hood on and went upstairs to wash my hands by the time I got back down to the car it was at 200 degrees. That's when I started playing around sealing the hood to the rad support. As I said it mad an improvement but still manages to creep up in traffic. I was thinking along the lines of what you were thinking. The aftermarket rad is a universal 26" and it does have a gap between itself and the rad support. I'm gonna get a roll of foam tape and seal it to the support and additionally I will also try to seal off the holes where the wires come through temporarily with duct tape and see what happens. Also I wanted to get your opinion on this. My hood scoop is there mearly to allow for clearance for the blower/carb and it is not sealed to air box for the carb. Do you think that this could also be an issue? I can't remember if I had this problem with the stock power bulge hood but I'm thinking I didn't.

THANKS to all of you for your valuable imput. I have been putting up with this for several years and I've finally decided that I'm gonna find the problem.

1968FormulaS340 said
If you had improvement with restricting hot air from getting to the front of the radiator I would look to see if you can do more in this area.

Block off all the holes in the core support leaving just enough open to allow wires to pass through. You can do this with duct tape when testing.

Some after-market radiators leave a big gap between themselves and the core support. If yours has this gap, it can be nicely filled with adhesive foam tape (found at RV supply stores).

How is the fit of the fan to shroud? Blades should be just inside the shroud and the fan diameter should be close to the diameter of the shroud opening.

Fan pitch could also be working against you. If you have a cheesy flex fan or one of those small bladed, plastic ones you may not be moving the air needed.

I really think getting all the hot air away from the front of the radiator and getting more air moving will solve your problem. I think this because...... When you get the car going and air is being naturally bushed in, your problems go away.