Packard Forum Index » Post-War (1946-54)

Also check the heat riser in the exhaust manifold to be sure it is not stuck closed.

I wouldn't think of an inoperative vaccum advance of being much of a significant factor in overheating in and of itself, perhaps in combination with other factors, but certainly worth checking out. But PackardV8s comment leads me something, though unrelated directly to overheating, is all to often neglected, and that's distributor lubrication. Sure we mostly remember the shaft oiler or grease cup, but the rotating bearing or sliding bumpers for the vacuum advance breaker plate motion require lubrication, as do the pivot pins and sliding surfaces for the centrifugal advance weights. Also often ignored is the felt wick below the rotor, critical to avoid wear of the cam block and shaft extension. Perhaps a downside of installing electronic ignition is that it tends to lead to "distributor neglect" with regard to these lubrication needs.

The radiator has been flow tested. However I am going to UV temp test it as mentioned earlier as a double check. The distributor was replaced so I will be checking it next. The timing mark moves predictably when the throttle is hit. This doesn't mean it can't use some grease and a checkup.
I have a pertronix electronic insert for a 6V neg ground if anyone is interested. Had it custom made before finding out that someone wired the battery wrong. Mine is a positive ground system.

One question about checking timing. I don't see a plate that has the degrees timing. All I see is a yellow line on hte balancer and a pin on the block. Am I missing something ?


OTG

The yellow line on the damper should be painted at the proper degree mark but you best verify. Just guessing, you check your owner's manual, but the timing should probably be 4 or 6 degrees BTDC.

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Owen, Can I ask you at what water temperature do you consider an engine as overheating and why?

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Late timing is another way of saying retarded timing. It is when it is too far advanced that the timing can cause an engine to run warmer and contribute to overheating. Also if the timing is too far advanced the engine will ping.

Bob1951 wrote Quote:
Late (retarded) timing is far more likely to cause overheating than early (advanced) timing, but neither is good, obviously.

Craig

Owen, Can I ask you at what water temperature do you consider an engine as overheating and why?

Sure you may ask, but my answer isn't in terms of a particular temperature but more in terms of how capable the cooling system is with coping with the engine heat under various conditons. For example, on a roaring hot day, idling in the blazing sun, if the coolant temperature rose significantly but did not boil, I'd conclude the car does not have an overheating problem.

If on a normal (let's say less than 90 degrees) day, driving at a constant and reasonable road speed, the temperature increased significantly above the normal (more or less the thermostat rating) temperature but still didn't boil, I'd say the car had a borderline problem, i.e. the cooling system was not able to fully cope with reasonably expected conditions.

My own expectation for a fully competent cooling system would be that in all but the most stressful conditions (blazing hot, minimal airflow across the core) the engine maintains a more-or-less constant coolant temperature. I'd except from that cars with shutter thermostats in the depths of winter.

If the coolant actually boils, I'd say the car has a certain overheating problem that requires attention promptly.

Those are my own thoughts, are yours significantly different?

EDIT: Let me add another example. A friend's 1950 Packard 8, on a cool (65 deg?) day, less than 10 minutes of idling from a cold start up takes the coolant temperature to about 200 degrees, though it doesn't boil. My conclusion is that this car has an overheating problem because the cooling system can't cope with a situation that the original design was expected to cope with easily.

According to my '51 owners manual, the temp gauge should be in the middle. It it goes to the H and stays there, it indicates a problem. If that is the case, I suggest you take the car to your nearest Packard dealer. LOL

It also states that unpressurized the water would boil at 212 degrees F, but under pressure it would boil at 227 degrees F. Not sure if that helps or not.

Have you checked your antifreeze to water ratio? I put too much antifreeze in a modern engine and had an overheating problem.

Ethylene glycol is not as efficient at heat transfer as straight water.