How to prevent overheating during parades

[starfireelvis]

Need some advice regarding obtaining an additional fan for my '62 Olds Starfire, 394 V-8, has air conditioning, with a six-blade fan and fan shroud. I am fortunate that because of the A/C, the '62 Olds was the first for the marque to have an alternator, which is a definite advantage over a generator regarding the application of low-speed travel as inherent with a parade.

For the record, I have driven approximately 2,000 miles in the past month, round trip from my home in North Canton, Ohio, to the NAOC National Meet in Lansing, Michigan, and the OCA National Meet in Sturbridge, Massachusetts. The car ran great, only thing I couldn't pass was the gas station...however, I can't make it 2 1/2 miles in my hometown for about an hour without having a problem. Could not have asked for a more perfect day to take part in the Pro Football Hall Of Fame Grand Parade in Canton, Ohio; the overnight low was in the upper 50s, and the morning temps could not have gotten above the low '70s at the most by the end of the parade (today's high was calling for near 80).

I have had to stop well short of the end the last three times I've taken part in the Grand Parade, only being able to finish about half of the route before the "hot" light came on, and according to others in the car and along the parade route, there was apparently some steam apparent, though I've never seen it any of the times I've had to pull over and quit.

I have taken part in this parade about four or five times prior to these problems without any problems, and have even been stuck for an hour in Chicago construction traffic after driving over 300 miles, without any problems, but whenever any extended idling takes place since these problems began, I now worry.

Had an engine rebuild about six years ago, with a radiator replacement at the time; I know the first couple of times in the parade following this, I had no problems.

I have tried additives that supposedly lower the coolant temperature 20 degrees, changed the thermostat (165 degrees), newer hoses, have the radiator flushed and changed every couple of years, and this year put a 12" diameter fan on, but apparently, to no avail. Put the proper-pressure radiator cap on (I believe it's a 15 PSI), know all about running the heater when this happens, revving the engine to try to increase circulation (maybe I shouldn't?). Of course, once I pop the hood, I see no steam, no signs of overheating other than the always-toasty Olds engine that is par for the course, and once I take off down the road, the light goes out after a quarter to a half-mile.

Don't want any comments about not taking part in the parade for whatever reason you think I shouldn't--it is a grand event, and next to Hershey is one of my favorite things to do, as it brings out a sense of pride in the town which I live, and connects with my other favorite hobby (To get an idea, I shook hands and obtained an autograph from Franco Harris of the Pittsburgh Steelers this morning--my favorite player as I was growing up--what a highlight for me).

Any suggestions for an additional fan, what diameter and design I should get (will try to get the biggest and fattest blade that will fit); should it be a "pusher" fan or a "puller" (I figure if you're going down the highway at 60 mph, that air is "pushing", isn't it??). Are the "S" blades better than the conventional blades? If you've had experience with this, let me know what does (and doesn't) work. Of course, want to know if there are other "tricks of the trade" that work.

The nice thing about the Olds is that there is a shelf between the radiator and the front grille, which hides the appearance of an auxiliary fan, thus keeping a "stock" appearance.

Sorry for the long-winded description here, just wanted to clarify any potential questions you might have in responding to this. Got a year to figure this one out, but do NOT want this to happen again; and again, given that I've done this several times before without any problem, there HAS to be a fix for this.

Thanks again,

Mike

[PONTIAC1953]

hi, could your problem be just a bad tempature sending unit ?, you say you're not seeing any steam, you might add a good mechanical water temp gauge to see what your old's temp really is. do you have an overflow tank ?, charles coker.

[rocketraider]

Mike, is this a clutch fan? If it is that would be the first thing I'd check. You should hear that fan roar when the clutch engages and that should be enough increased airflow to keep it cool in extended idling. I would think a factory air 62 would have it; I know my factory air 64 does.

Also check base timing and distributor advance.

I expect this nonsense we have for fuel now has some effect on it too since it makes these cars run so lean.

I've had more than one sender unit go wacky on my 64s. The temperature bulb would get offcentered just enough that when things heated up and it expanded, it could ground against the sender body. Had one that would do it immediately after the cold light went out. I took a hammer to that one to make sure it could never offend again...

[Guest pfloro]

I would check the ignition timing. If it's retarded, the engine will run hotter. If it's set to factory specs, you might consider advancing it a couple of degrees & see if there is any improvement.

With our '66 Mustang (289 V8), I speak from experience. This car had a hot running engine for several years. It was especially troublesome at idle. Cutting to the chase, I finally tried advancing the base timing from 6 degrees BTDC to 12 degrees. The hot running immediately disappeared. It was amazing. Please note that TDC for cylinder #1 was verified against the harmonic balancer timing mark (the outer ring hadn't slipped).

Keep us posted.

Paul

[starfireelvis]

Thanks for all the responses; I will check these suggestions out accordingly. I did change the temperature sending unit about six weeks ago (best deal I ever got on e-Bay, by the way--thought I had bought one for $12, and ended up receiving 12 of them for $1 apiece). Cold light works fine, hot light (apparently) works fine as well...

Interesting to note the timing and the fan clutch, I will check those things out for sure, along with anything else that comes down the pike.

Thanks again for your help--still welcoming other suggestions as well, of course...

Mike

[bill pritchett]

You definitely have a clutch fan as I have a 61 with factory air and had to replace the clutch fan.

[starfireelvis]

Just following up here; is there any way for me to do some simple troubleshooting at home that could help determine my problem? For example, could I test to see if the clutch fan is working by trying to rotate the fan while the engine is off; i.e., would that tell me something one way or the other if it moves/doesn't move?

As for the dieseling, I understand I would need to get the timing light out and see if I'm doing OK (again, car runs f-i-n-e except for that morning going 5-10 mph down Cleveland Ave. in the heart of Canton), but would there be any other sorts of "adjustments" I could pursue that might help?

Thanks again,

Mike

[stealthbob]

Just following up here; is there any way for me to do some simple troubleshooting at home that could help determine my problem? For example, could I test to see if the clutch fan is working by trying to rotate the fan while the engine is off; i.e., would that tell me something one way or the other if it moves/doesn't move?

As for the dieseling, I understand I would need to get the timing light out and see if I'm doing OK (again, car runs f-i-n-e except for that morning going 5-10 mph down Cleveland Ave. in the heart of Canton), but would there be any other sorts of "adjustments" I could pursue that might help?

Thanks again,

Mike

Here is a short write up on clutch fans....

The fan drive clutch is a fluid coupling containing silicone oil. Fan speed is regulated by the torque-carrying capacity of the silicone oil. The more silicone oil in the coupling the greater the fan speed, and the less silicone oil the slower the fan speed.

Two types of fan drive clutches are in use. On one a bi-metallic strip and control piston on the front of the fluid coupling regulates the amount of silicone oil entering the coupling. The bi-metallic strip bows outward with an increase in surrounding temperature and allows a piston to move outward. The piston opens a valve regulating the flow of silicone oil into the coupling from a reserve chamber. The silicone oil is returned to the reserve chamber through a bleed hole when the valve is closed.

On the other type of fan drive clutch a heat-sensitive, bi-metal spring connected to an opening plate brings about a similar result. Both units cause the fan speed to increase with a rise in temperature and to decrease as the temperature goes down.

In some cases a Flex-Fan is used instead of a Fan Drive Clutch. Flexible blades vary the volume of air being drawn through the radiator, automatically increasing the pitch at low engine speeds.

Do not operate the engine until the fan has been first checked for possible cracks and separations. If there are signs of leakage, then it needs to be replaced.

Run the engine at a fast idle speed (1000 RPM) until normal operating temperature is reached. This process can be speeded up by blocking off the front of the radiator with cardboard. Regardless of temperatures, the unit must be operated for at least five minutes immediately before being tested.

Stop the engine and, using a glove or a cloth to protect the hand, immediately check the effort required to turn the fan. If considerable effort is required, it can be assumed that the coupling is operating satisfactorily. If very little effort is required to turn the fan, it is an indication that the coupling is not operating properly and should be replaced.

If the clutch fan is the coiled bi-metal spring type, it may be tested while the vehicle is being driven. To check, disconnect the bi-metal spring, and rotate it 90 degrees counterclockwise. This disables the temperature-controlled free-wheeling feature and the clutch performs like a conventional fan. If this cures the overheating condition, replace the clutch fan.

Another way to check it is to listen to it. Let the engine idle and when the clutch fan heats up enough to engage, you'll hear a change in sound. It will sound like a roar which indicates that it is actually pulling air.