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I've been around here for over 10 years and this topic comes up every summer like clockwork. People expect the 50-60 year old cars to perform like a 2017 MBZ during the summer heat. These cars overheated back in the day, and today's conditions with more people and heavy traffic just make it worse. The car gets hot sitting in traffic and everything under the hood gets heat soaked, not just the radiator water. With everything under the hood blistering hot it would take a heck of a cooling system to bring the temp back down at 60 miles per hour on a short ride after sitting at 220* for any length of time.
If you want to enjoy a stress free ride on a warm summer afternoon you need to upgrade your cooling system to match your expectations of your car. A/C on, 90-110 outside? You need to draw a lot of air through the radiator. Go outside and disconnect the electric fan on your 2016 BMW, run the A/C on a warm day and get back to us on how long that worked out for you, even on the freeway with all that air blowing through the radiator.
You can fight it or justify it all you want, but for me I got tired of having one eye on the road in my old Corvette because it has manual steering and manual drum brakes in traffic where everyone else has 4 wheel power disc brakes and can stop on a dime, while having the other eye on the water temperature gauge praying that it doesn't get any higher than 220*.
Like I said, I hid a 16" Spal electric fan against the radiator inside my shroud in front of the original fan and fan clutch, and I have driven it in 105 degree days in very heavy L.A. traffic and it never gets much over 180*. I have a Dewitts aluminum restoration radiator. The engine is a Blueprint crate long block 383 stroker (435HP with 465 ft lbs of torque per dyno sheets) with a roller hydraulic cam hooked to a lock up torque converter and a 700R4 automatic overdrive meaning I can't even push in the clutch to give the engine a break. To make matters worse I put a Hayden transmission cooler in front of the radiator for the auto trans. I monitored trans temps and on the hottest days it never gets over 125*
As the original poster let me add a couple of more factors. First. The car with AC on and moving at a decent speed DOES NOT OVERHEAT! On the highway at 95 degrees with the AC on, temp (checked with IR) does not exceed 210 degrees. In stop and go traffic. the temp will reach yellow, headed for red, so I turn the AC off. I have a Harrison aluminum radiator, seven blade fan, which is entirely in the shroud, so I think that I have covered all the bases. I'm beginning to think that the '66 without an electric fan is going to be a chronic overheater. Since the car is an NCRS car, I have been hesitant to install an electric fan. The problem is a pain in the *** in this hot weather.
As the original poster let me add a couple of more factors. First. The car with AC on and moving at a decent speed DOES NOT OVERHEAT! On the highway at 95 degrees with the AC on, temp (checked with IR) does not exceed 210 degrees. In stop and go traffic. the temp will reach yellow, headed for red, so I turn the AC off. I have a Harrison aluminum radiator, seven blade fan, which is entirely in the shroud, so I think that I have covered all the bases. I'm beginning to think that the '66 without an electric fan is going to be a chronic overheater. Since the car is an NCRS car, I have been hesitant to install an electric fan. The problem is a pain in the *** in this hot weather.
First off, the fan should be half in and half out of the shroud to optimize its' efficiency. Secondly, how old is your radiator? And third, listen to those telling you about your fan clutch. I went thru this same hair pulling process three summers ago. New DeWitts restoration radiator, new hoses, flushed the cooling system, new 180* thermostat, seven blade fan (half in/half out) and still experienced 220* plus in stop and go traffic when 95* plus ambient. Finally installed a new K&B fan clutch...problem solved. I barely see 200* in Dallas summer heat. Give it a try as I thought my fan clutch was functioning, as well
As the original poster let me add a couple of more factors. First. The car with AC on and moving at a decent speed DOES NOT OVERHEAT! On the highway at 95 degrees with the AC on, temp (checked with IR) does not exceed 210 degrees. In stop and go traffic. the temp will reach yellow, headed for red, so I turn the AC off. I have a Harrison aluminum radiator, seven blade fan, which is entirely in the shroud, so I think that I have covered all the bases. I'm beginning to think that the '66 without an electric fan is going to be a chronic overheater. Since the car is an NCRS car, I have been hesitant to install an electric fan. The problem is a pain in the *** in this hot weather.
When I went to A/C on my 63, I put a thermostat controlled puller fan in the shroud, ahead of the belt-driven one. You can't even really see it (or tell it's there) until the car gets hot and it kicks on. The gauge says 180 even after a long drive (my measurements say that's about 5-10 degrees lower than reality, but its and old gauge). I haven't seen 95 ambient outside yet, but I don't think that'll be a problem.
If your car cools well at speed, you just need to keep the air flowing well at idle and it'll be cool then too. The electric fan will do this, so put the electric fan in and take it out for any future judging. It's not an irreversible change and it's not that big a job to take it out.
As the original poster let me add a couple of more factors. First. The car with AC on and moving at a decent speed DOES NOT OVERHEAT! On the highway at 95 degrees with the AC on, temp (checked with IR) does not exceed 210 degrees. In stop and go traffic. the temp will reach yellow, headed for red, so I turn the AC off. I have a Harrison aluminum radiator, seven blade fan, which is entirely in the shroud, so I think that I have covered all the bases. I'm beginning to think that the '66 without an electric fan is going to be a chronic overheater. Since the car is an NCRS car, I have been hesitant to install an electric fan. The problem is a pain in the *** in this hot weather.
I don't know about C2's, but installing one in my '62 wasn't too difficult and won't "ruin" your car if done right. I made an upper and lower brace for the fan out of 1/8" x 1/2" strap from Lowes, drilled 4 holes in the radiator support, countersunk them on the face of the support, slipped the straps on the inside lip of the support on each side of the radiator, used countersunk allen head bolts so the shroud when reinstalled would still sit flush on surface of the support, and ran the wiring so you'd never see it. If anyone wanted to remove it all that would be left would be the four 1/4" countersunk holes in the support that are hidden when the shroud is in place. All that for piece of mind.
Unless you point it out no one will ever see it unless they hung over the center of the engine and looked directly into the radiator through the shroud like this photo. The round water pipe insulation between the radiator sides and the support ends that helped seal the radiator were later pulled out. Didn't need them.
Thanks for all the input. The Harrison radiator is relatively new, and the seven blade fan is partially in, partially out of the intact shroud. New thermostat installed last year. I really think that everything that needs to be done, has been done. I will have a mechanic check the fan clutch. When the motor is off the fan can be turned, but there is a small amount of resistance when I manually do this. I'm not much of a mechanic and have to rely on professional help. Thanks again.
Thanks for all the input. The Harrison radiator is relatively new, and the seven blade fan is partially in, partially out of the intact shroud. New thermostat installed last year. I really think that everything that needs to be done, has been done. I will have a mechanic check the fan clutch. When the motor is off the fan can be turned, but there is a small amount of resistance when I manually do this. I'm not much of a mechanic and have to rely on professional help. Thanks again.
If you can take one finger an easily move the blade with little effort forward it's bad.
It should take some effort to move it that you can feel, and will stop as soon as you remove your hand if you really try to spin it if it's good.
Hope your professional not like the one my friend with EL Camino was using, and the guy was no spring chicken.
I'm an "X" professional from the 70's. Gave it up in the 80's for more income and an benefits working with my mind...LOL
I think new Fan clutch was around $30.00 dollars for my friend car.
People are asking to much from their radiator it they have air and on a 90 degree day and in traffic. It's going to get hot, esp a 63. At least on newer C2's you have the open louvers on the fender side.
I've been around here for over 10 years and this topic comes up every summer like clockwork. People expect the 50-60 year old cars to perform like a 2017 MBZ during the summer heat. These cars overheated back in the day, and today's conditions with more people and heavy traffic just make it worse. The car gets hot sitting in traffic and everything under the hood gets heat soaked, not just the radiator water. With everything under the hood blistering hot it would take a heck of a cooling system to bring the temp back down at 60 miles per hour on a short ride after sitting at 220* for any length of time.
In 10 years of driving my '61 dual quad car in Orlando's steamy summers my car never got over 190-200; it never approached that third tick mark. You had something else amiss. In cooler weather the temp stayed on the lower end. My car did not have A/C but several mods to enhance cooling.
Last edited by Frankie the Fink; 07-16-2017 at 07:10 AM.
People are asking to much from their radiator it they have air and on a 90 degree day and in traffic. It's going to get hot, esp a 63. At least on newer C2's you have the open louvers on the fender side.
My 63 coupe with Vintage Air A/C in Orlando summer heat might creep up to 200* at a stop light but quickly goes down to 185* or so once moving. Again, I run a 7 blade 18" fan with a Haydan 2747 truck clutch with an original radiator. I hate the look of electric fans on a stock car...but would do it if I had to.
In 10 years of driving my '61 dual quad car in Orlando's steamy summers my car never got over 190-200; it never approached that third tick mark. You had something else amiss. In cooler weather the temp stayed on the lower end. My car did not have A/C but several mods to enhance cooling.
What kind of gearing do you have to turn that low an RPM at 65 mph?
I have an overheating problem with my A6 when in city traffic and the temps are in the 90's. Car is NCRS, and I do not want to have to install an electric radiator fan.
Timing has been checked. Temp overheating is verified by IR gun. Fan shroud is intact, and fan clutch works. New thermostat. A6 compressor has been checked and charged.
Car is factory AC/ 327-300hp/ auto tranny/ 3.36 gearing/ and the AC does no overheat on the highway ..... only stop and go city traffic.
Think that I have covered it all. The car had the same problem with hot summer temps last summer, so I just run the AC on the highway, and sweat in city traffic.
Define overheating. What is the gage reading and what are the corresponding IR gun readings on the upper radiator hose.
What is the timing value? Also, what is the number on the VAC and does it meet spec? (If by chance it's a California K-19 car, engine code HR, with ported vacuum advance, the severely retarded idle/low speed portion of the spark advance map is definitely a problem.)
Does the radiator cap hold rated pressure? Is it expelling coolant out the overflow hose?
Have you tested the fan clutch for proper function - gets much tighter when the coolant temp is over 200-210?
With a 15 psi cap and a 50/50 glycol/water blend the boiling point is 265, and it should not expel coolant until very close to this.
Simply shifting into neutral and bringing revs up to 1500-2000 when you are stopped should bring the temperature down assuming all cooling system components are in proper working order, and it has a proper spark advance map.
Every year we go to Cruising the Coast in southern Mississippi. This is by far my favorite event. You go knowing full well it's going to be be hot and you are going to be in major traffic. When I say major you know it's gona take 3 hrs to travel 6-8 miles. It will test every cars cooling system to the max. I used to go in my C4. It's 100% stock. The fans don't come on until 230 & 237* I think it is. It would get very close to over heating. So as Randy G. correctly stated when everything gets heat soaked it's not going to cool with a marginal system. Every year we see cars pulled over to the side puking water or reving them up in traffic trying to keep them cool. On my 66 GTO I just sit and wait to move forward at 180*. I have 2 11" puller fans and an 18" pusher. So it's pretty simple move enough air and it will cool don't and watch it overheat. Myself I would go with trying to hide it in front of the original fan.
I have been driving factory air cars since the mid 70s. In mid 90s temps driving in heavy city traffic my cars would hit 235 and level off but never boil over, a proper coolant mix with a good 30# cap wont boil till about 260. Midyear temp gauges have always been inaccurate a IR gun is a most. I have put the Hayden 2747 clutch on several cars and seen a big improvement and a 15 min job to swap out for NCRS events.
Mark
I had a C1 that overheated, the only way to bring temp down during traffic stops was to turn on heater. Made for a very hot day in the summer. They have really came a long way in design of engines/cooling systems. My new Toyota, the temp gauge will jump up to the mid range and stay there, summer or winter, traffic of traveling.
What kind of gearing do you have to turn that low an RPM at 65 mph?
Tremec TKO-600 5 speed w/ overdrive and a 3.70 rear end. The car has been sold but it was (is) a magnificent high-speed cruiser...
I spent a lot of time in 4th gear w/o overdrive...you pretty much had to hit 50+mph for the car to stay in the sweet spot in 5th gear and not lope...still ran cool..
The Hayden 2747 (truck) fan clutch kicks in at lower temps and runs at a higher percentage of engine speed than the stock set up. I've changed fans and fan clutches as one piece without even loosening a fan belt; a bit tricky but it can be done.
Here is a ton of info on fan clutches by a premier expert:
People are asking to much from their radiator it they have air and on a 90 degree day and in traffic. It's going to get hot, esp a 63. At least on newer C2's you have the open louvers on the fender side.
People are using a system designed 65 years ago for 200 to 300 hp cars. Horsepower is heat, and many have raised their horsepower much higher than the original amount. Ever wonder why the big blocks use a larger radiator and the 396 and the L88 used an aluminum radiator that was much larger than the small block aluminum?
People have also added air conditioning, which introduces both drag and air flow restrictions with the condenser.
And you are dealing with a system designed by guys who didn't really understand airflow and cooling as evidenced by the story of the '68 and its cooling problems.
In 10 years of driving my '61 dual quad car in Orlando's steamy summers my car never got over 190-200; it never approached that third tick mark. You had something else amiss. In cooler weather the temp stayed on the lower end. My car did not have A/C but several mods to enhance cooling.
Frankie you were part of all this. Almost two years ago if you remember I was posting almost daily what was being done to fix the overheating issue, including a new DeWitt's restoration radiator, Hayden 2747 fan clutches, distributor, vacuum advances, water pump, etc. I did everything you and everyone else suggested including sealing the radiator all the way around like you showed me you did in your pictures. You can find my thread on the subect if you do a search, which ended up being multiple pages. One by one people said they gave up on ideas to help.
The last thing I tried was duct taping every single joint and gap between the radiator, shroud, support and everywhere else. It still got hot unless you were moving. I took out the 350 targetmaster engine and swapped it for a brand new Blueprint 383 and when the gauge started climbing with it I said enough is enough.
Oddly enough, we had a restored top flight fuel injected '57 Corvette with a 100% stock cooling system that never got hotter than 190 degrees no matter how hard you tried. It's as if some cars are fine, and thousand of ideas and thousands of dollars later some aren't.
Chasing an overheating car when the goal is to be able to take stress free rides in them sucks. For just a very few bucks and a little fan noise my car will never ever overheat again. And the way I hid the fan no one has ever spotted it unless the topic of overheating comes up and I tell them to lean in over the engine and look in front of my fan and fan clutch.
In regards to the hidden electric fan, how many point would he lose for judging, or is an electric fan a major no-no for NCRS judging?
Also, you said you have a 7 blade fan, that's not NCRS either, is it? One of the major suppliers sells a 5 blade fan with additional pitch, has anyone tried one? Try a new radiator cap, may be that simple, hot is hot, however if it's not puking, it's ok, Just some thoughts.
07-15-2017, 04:46 PM
