nailhead cooling issues

new2buicks · 07-02-2006, 10:24 AM

Hey everyone. I have a '63 Riv with the 401 and it has A/C, so there is a condenser in front of the newly re-cored rad. I am running a Flex-a-lite electric fan that turns on at 180 degrees (2800 cfm). I have installed an Auto-meter mechanical temp gauge in the front of the passenger side head , where the factory cold/hot light sensor was. The problem is that even when running down the highway at 65 mph the engine still creeps up to 210 degrees, and it was only about 80 degrees outside temp. I am looking for any suggestions you guys have including some tips on where to find a set of underdrive pulleys or something that could help.

Thanks in advance.

**Robert Bates** · 07-02-2006, 03:16 PM

What else do you have under the hood besides A/C?

Are you getting good airflow across the radiator?

Is the A/C Factory or aftermarket?

Where is the sensor for the fan?

Does it run off the sensor location for the gauge or from somewhere else?

What was the airflow rate for the factory fan?

Sounds like an airflow issue but it could be something else entirely, I might have some more insight if you can answer the above questions.

Bob

**mottrodder** · 07-03-2006, 08:27 AM

Since you are having overheating problems at highway speed as well as at slower speeds, I suggest doing the following: 1. Make sure the fan belt is tight. 2. Inspect the fan belt at both the water pump and crank pulleys. The belt should contact the sides of the "v" on the pulley. This means the "v"s or sides of the pulleys should be clean and shiny and the base of the pulleys darker. To verify this, remove the belt(s) and coat the entire "v", including the bottom, with a magic marker. Reinstall the belt and run the engine. Verify that the belt is contacting the sides of the pulley. If the belt is contacting the bottom of either pulley, you are getting slippage and reduced water pump RPM. Replace the belt with one that contacts the sides or replace the worn out pulley. 3. With the engine at operating temp (or higher), look at the lower radiator hose and rev the engine, if the hose "sucks in" or collaspes, replace the hose. To further check the lower hose, if you are confident you can do this safely, manually squeeze the lower hose with the engine running. If it collaspes or deflects easily, replace the hose. 4. Replace the thermostat on general principles. Since you have an aftermarket electric fan, I would consider this as suspect. If you still have the parts, reinstall the factory fan and fan shroud if the car came with one. Install the electric fan on the front of the AC condenser and wire it to come on when the compressor comes on. However, since you are having problems at highway speeds as well, I would not think the aftermarket fan is the root cause of the problem. Look at the way air flow is "managed" starting at the grille. Try to determine if the air is flowing through the radiator and not around it. This may take some careful analysis. Retarded timing can also cause an engine to run hot. Time the engine to specs. Remove the cap and rotor and make sure the advance weights are moving freely. After you solve the problem, consider adding a container of "water wetter" such as Redline, it really works and is added insurance. The challenge on 40 year old cars is that anything could be the problem. People change things over the years and weird things wear out. It would be appreciated if you stay in touch and let us know how you solved the problem. Good luck.

new2buicks · 07-04-2006, 09:28 AM

Here are some more details on the car, as Mr. Bates requested.
It has the usual Riv stuff, like power steering, A/C compressor, alternator and waterpump running off the engine. As far as "what else is under the hood"- power brakes, cruise all the regulars.
I am certain that I have good airflow through the new rad because when the fan is on and I hang on of those "heavy" blue paper towels in front of the grille it gets sucked to the grill and will stay there as long as the fan is on.
The A/C system is 100% factory.
The fan sensor is one of those little "bulb" style ones that sits between two fins on the rad. You just gently push it through the core. It is located right below the coolant inlet port on the rad. I think this is a good location for it because when I have the fan set to turn on at 160 degrees it comes on when the gauge reads about 165. The gauge sensor is in the head, where the factory "hot/cold" sensor belongs, it is NOT on the exhaust side but I would still believe that this is one of the hottest areas of the engine.
I have read that nailheads do like to run on the hot side, but how hot is too hot (what is normal operating temp for you guys?).

I have checked for belt slip but had kinda ruled it out due to the wear pattern on the freshly painted pulleys. The belts do not seem to be bottoming out in any of the three grooves.
As far as the bottom hose collapsing, that was a concern of mine when I sent the rad out for recoring so I went and got myself one of the coiled wires that newer vehicles use in the bottom hose. So that is definately not an issue. As I stated in the relpy to Mr. Robert Bates, I also do not think the airflow of the fan is suspect because of the huge amount of air that it pulls through the grille.
Now for the issue of timing as Mottrodder suggested. I would tend to believe that this may be part of the problem. When we put the car back together and I was trying to time it I realized that the outer ring on the balancer had slipped out of alignment. I put the #1 cylinder at TDC, marked the balancer at zero, and timed the engine to 12 degrees BTDC. Now, last week when I installed the MSD distributor I found even my new TDC mark had moved so far out that I had to set my digital timing light to 90 degrees advance to even see the old/facrory timing mark. So to time it this time I just got it running and set it by ear. However, I am sure that it is not retarded since I have 22 degrees of advance set in the distributor and I took the car out anf when I floored it the engine rattled a little bit. I took the car home and backed it off until it would stop pinging at full throttle. Definately not the best way, but it'll do the job until I get the balancer rebuilt. By the way, who rebuilds them?
Now, onto the Water Wetter. I plan on trying this once we figure out the actual problem. It seems like a band-aid type of fix to me. Once the car runs reliably at about 190, then the Water Wetter will go in.
Sorry I wrote so much but I wanted to answer the questions as well as I can because I need to get this fixed properely.
Thanks for the quick replys guys. Sounds like we may be getting somewhere.

**Robert Bates** · 07-04-2006, 12:10 PM

Ok..........what degree thermostat are you running?

I run a 180 degree thermostat in my 1955 264 and never have a problem, but the motor is completely factory stock, for now. When I got the car it had no thermostat and ran about 160 degrees all the time

Does the fan manufacturer have a recomendation for sensor location?

Bob Bates

**mottrodder** · 07-04-2006, 02:05 PM

You have done a lot of troubleshooting already. So now that the "easy" stuff is out of the way, the fun begins. This is where I would start looking for odd stuff. The new mechanical gage be be reading too hot, you may not have a problem at all. Verify the gage by placing the bulb in boiling water and see how close to 212 it reads, or place a hand held thermometer on the top hose (or wherever you think is best) and see what kind of temp reading you get. A meat thermometer with some kind of insulation over it may work. Also, the reading may be accurate but maybe Buick put their sensor purposely in a hot spot. The coolant temp overall may be within an acceptable range. Again, you may not have problem. Does the car eventually boil over or continue to run hotter and hotter? I am running out of ideas. Maybe someone else can contribute more.

Regarding rebuilding your damper: There was an excellent article in the Oct 1996 Street Rodder magazine about an outfit named "DAMPER DUDES" There are (or at least were in 1996) at: 1055 Parkview Ave, Redding Ca 96001. Info phone 916-244-7225 Order phone 800-413-2673. The article was very complimentary to the point that I saved it in case I needed a rebuilt damper. I have never had to contact them, so I can't recommend, critcize, or even confirm they are still in business. Please continue to keep us informed on what you are doing. It is always fun to learn something when someone else is doing the work! Please note, my recommendation for water wetter was for AFTER the root cause was found and the problem corrected. I get the impression you do not like band aid fixes and neither do I. Good luck.

**telriv** · 07-04-2006, 05:15 PM

Damper Dudes do a good job of revulcanizing new rubber on the old balancer. ONE CAUTION!!!!!!! Make absolutely sure where the fine balancing pins are located in the small outer holes of the damper. On a piece of paper mark down the specific locations & also tell Damper Dudes to please replace them in the exact same spots. When they rebuild these dampers most always the pins are removed. If you don't know where they were or how many you will be fighting an engine vibration that you didn't have before & will drive you as crazy as this cooling system thing.
Too little timing is just as bad as too much timing. With most stock NailHeads total timing should be about 30*-34* total mechanical. Add another 10*-14* vacuum advance & timing issues related to cooling should be irrelavant. One thing many forget is that the coolant can flow TOO fast & not have time to transfer the heat. In this case a restrictor needs to be installed. This could be as simple as a big washer in the upper hose to slow down coolant flow. Try different size openings in the washer. I use 5/8ths. of an inch.
Just more thoughts.

Tom T.

**62BuickFan** · 07-05-2006, 06:38 AM

I have a 62 401 with a 160 thermo, and the hottest it gets is about 180 going down the highway. I don't have a/c or anything on it. It has stock fan and no shroud. In stop and go traffic in the summer, it gets hot on me. But, driving down the road it hasn't overheated.

How old is the water pump? Could the impellers be corroded down and not circulating water as it should? Are you for sure that the thermostat is opening all the way, and what temp is it? It maybe stuck in one spot. Could you have an obstruction in your water jacket?

What gas are you running in it? If you are not running minimum 91 octane, then you will ping way early. Therefore, you might have the timing set to far back. I would definatly get the harmonic balancer figured out before I drove it anymore. That still could be your issue.
Next would be to try an aluminum radiator.

Can you bring the temp down with the electric fan?

**mottrodder** · 07-05-2006, 06:50 AM

Telriv, thanks for the info on the dampers. I knew dampers had a lot to do with engine balance, but didn't know what the real world solution damper repair/replacement was. Some additional thoughts: Could the thermostat in upside down? Also, too lean an air/fuel ratio can cause overheating. Has the carb been altered or replaced? Very remote possibility, but easy to check item-replace the fuel filter, it may be causing a lean condition at speed. Ask the radiator shop if the new core has sufficient rows of tubes and if the fins per inch are near what the factory unit had. If the problem still exists after all items have been checked, it is time to recheck and then start over. Some questions that may offer more info: When did the hot running condition begin? if the car is left to idle for a long time, does it still go to 210, or does it stay at a lower temp? How hot will it actually get if you drive it for a long time? Why was the core replaced? rot, old age, leaks, or overheating? How did the coolant look when you drained the system? Could the engine be crudded up" If you flushed the engine, could crud have left the engine and plugged the new core? From your remarks, it sounds like you did a lot of work, did you rebuild the engine, change the cam etc? Can head gaskets be installed improperly, blocking some passages? If you have access to one of those hand held battery powered infared thermometers, you could get a reading on coolant temp in the radiator. Since you have new information, (actual temp from the new gage). You may be suffering from excess information syndrome. Maybe at always ran that hot and was OK , you just didn't know the actual temp. Thanks for keeping us informed. Good luck. Hope your next post details your success.

**SFC ROCK** · 07-05-2006, 02:14 PM

Just a thought , but you said that the fan thermo switch in between some core tubes in the rad.It would seem to me that it should be installed in the water jacket of the engine block.That is where most are placed on the eletric fans setups I've worked on.If this is how this is ment to be then I would feel both hoses (upper and lower)and see which one gets warmest before the themostate open.I believe you will find it will be the lower one.

Rocky