Hello ,

I have a '68 cutlass convertible and have recently had the engine rebuilt with a .030 bore , aluminum intake , 600 cfm carb , hei dist , and headers and new flex fan . My problem is if I drive it in the city , it runs about 190 -200 degrees and wants to stall out . It's driving me crazy .

any help would be very much appreciated . Thank You.

Joe

 

Is your radiator a 2 or 3 row unit and have you tried to have it flushed. I am not in favor of the flex fan. I believe you would be better off with a stock clutch fan. Less noise and if the radiator is working correctly should work fine

1. Is the fan shroud in place. Critical to focus the air flow through the radiator.

2. Is the thermostat a 180 degree unit and is it opening all the way. Simple test take it out and put in a pan of water, heat the water and use a thermometer to verify that it opens

3. take off you radiator cap and look at the tubes are they crusty and scaley with crud. feel the front of the radiator are there places were it is cool if you find any of these your radiator is not cooling correctly and needs repair

4. Is it a 350 or a 455? If you are running a 455 you should have a minimum of a 3 core radiator.

Check all of this and see what you find out

 

Pat ,

Thank you for your help . My engine is a 350 Rocket . I had a clutch fan with the 190 degree thermostat and shroud in place and it Overheated all the time. the guy at the speed shop told me to use a flex fan and a 160 degree thermo , and it runs 100 % better . I have a 2 row in the car now , but will put a 4 row in it very soon , better safe than sorry . thank you again .

Joe

 

I had similar heating issues w/the Silver Bullet, 350 CI w/a similar rebuild (.030 over and mild Isky cam). Replaced original stock radiator w/2/core aluminum radiator, running original fan shield/fan, and problem solved, period! Might want to check that out w/a/knowledgable shop/tech.