'66 Beaumont with a mild 454 (early '70s passenger car or light truck engine, built before I bought it), mounting Holley Terminator EFI, running a Cold Case aluminum BBC rad, and a high flow aluminum water pump. Dual electric fans, on at 165F, off at 160F. Fresh Prestone coolant, with wetting compound. 165F thermostat, working properly, and when I removed it, things didn't change noticeably.
Runs 190-195F @2600-2800 RPM, 65-70 mph, quickly gains temp in city driving, and climbs uncontrollably when stopped in traffic. Saw 220F on the Holley controller read out (Dakota Digital temp gauge was declaring 230+). This with the Vintage Air off.
Even fabricated a rubber deflector to seal off the flow under the bumper and direct it up into the rad, like GM did for the Gen 1 F-bodies with the BBC (396).
Yes, the ambients here are in the 35C range, but that just accelerates the overheating, doesn't change the terminal outcome.
Anybody have any suggestions? I have been hoping to run her up to her birthplace for a few days, before the Woodward Ave. Dream Cruise, but there's no way I'm braving the West Virginia Turnpike with this problem, let alone the stop-and-go profiling along the boulevard during the event.
Frustrating, and expensive. Probably more of both to come.
-- Edited by see2xu on Monday 17th of July 2023 04:46:21 PM
Are the cooling fans turning in the right direction? I looked at an overheating problem and the fans were blowing out the grille. The fans were installed on the wrong side of the radiator and werent reversible. Moving the fans so they would draw air in the front solved the problem.
On the highway air coming through the grill keep temps ok. Slower speeds depend on the fans. May need fans with more volume or better shroud. The Cold Case rad I put in my car had a smaller fitting than the original for the overflow and was letting air into the system. Was running hot until I installed new hose that fit tight to seal system. Will watch for you on Woodward. Barry
Do you know if the engine was bored out? I seem to recall too much overbore can cause an overheat issue. Blockage in the water jackets?
this is what i would be thinking also try retarding the timing
actually advancing the timing helps cool the engine. Pontiac Engineer John Sawruck indicated this in one of his presentations at POCI Nationals in the early 2000's.
Do you know if the engine was bored out? I seem to recall too much overbore can cause an overheat issue. Blockage in the water jackets?
this is what i would be thinking also try retarding the timing
actually advancing the timing helps cool the engine. Pontiac Engineer John Sawruck indicated this in one of his presentations at POCI Nationals in the early 2000's.
Not necessarily. My 57 was over heating at every stop/light. Soon as I stopped the car the temp went up. Dizzy had moved 12 more deg adv.....backed her up and overheating stopped.
Wow - that's a coincidence! Two of my pals were planning on the Southern Pines to Concord leg, but both had heating problems. One's a BBC in a '66 Chevelle, carbureted 5 speed, the other a 283 with the same EFI as my car in a '57 post. The latter had the fan-on set at 190F, off at 180F, which is the default on the Holley system we both have. Setting his lower solved his problem but hasn't fixed mine.
Hope you enjoyed the event - I ended up having to pass, despite having registered, in deference to a family celebration.
Yes, Gillis, it's got dual electric fans in a fitted shroud. Plus the deflector my pal fabricated to push the air up from under the bumper, through the rad.
The timing was too far advanced last summer, setting it back brought cruising temp down about 10F, but the peak was still warmer than I liked. Long story, but lost the EFI tune and am trying again from scratch - that, and the steamy July we've had down here have conspired to make it run too warm for comfort. Gets to 220F indicated at about 90 km/h on country roads in ~30C ambients, a/c off. That's using the programming tool readout for jacket water temperature, not relying on the instrument panel, which reads about 10F warmer under those circumstances. But, still too hot.
