Can't keep my ZZ4 engine cool

[Bonzi]

Hi all. This has been the most frustrating part of my engine swap. I own a 1989 Toyota Supra and yes I replaced the engine with a ZZ4 from GM. I wanted a muscle car feel in a well handling car. And i am very happy with the project. I have working A/C and power steering along with a t-5 trans that fits perfectly. My only problem is cooling. I installed an aftermarket aluminum Supra radiator. A 160 Thermostate ( I tried a 180) I built a custom fan shroud with two fans that pull. I have a fan in front of the A/C and hood scoop for air.

I live in Flroida which does not help. What happens is as long as I am moving the car will run at a constant temp between 200 and 220. I would like it to run no more then 200. The problem is when I stop for a light. The temp slowly rises until it it approaching 230. To get by I have to shut off the engine and keep the fans running. It will drop fast and off I go. In the evening it runs great. In the winter it runs cool. It's the hot Florida days that kill me. I have tried adding cooling fluid. NO Good. I have tried adding two heater cores for all water, no good. I even added a second radiator where the intercooler used to be. No Good. My next step was to add as many hood vents as possible. I really do not know what else to do. I tink the second radiator did not work because it throws hot add to the original one so I am not accomplishing anything.

Please any ideas. The car looks good and sounds great. Handles like a dream. Just to Hot.
The installed said I am paranoid. Running 220 in not that hot.



Any ideas. First time poster.
John