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

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Maybe I'm missing something here. What exactly do you mean by "When the engine overheated" ? Did it boil over? An engine temperature of say 220 degrees, or even higher, in a pressurized system does not mean the engine is overheated.

Quote:

Maybe I'm missing something here. What exactly do you mean by "When the engine overheated" ? Did it boil over? An engine temperature of say 220 degrees, or even higher, in a pressurized system does not mean the engine is overheating.

I used a UV tester and confirmed that the block temperature around the thermostat and at various points down the side of the block is approximately the same as the temperature indicated on the gage. This is a given. The gage had a reading of approximately 250+degrees (guesstimate) and the engine compartment was hot enough to give you 2nd degree burns if you came within a foot of the block. It did not "overheat" because the radiator didn't perk over? Interesting.. have to think about that one.

Can't wait for warmer weather so I can overheat the beast and do a UV temp check on it to see at what point the engine seizes.

BTW the Rad guy obviously never saw a REAL radiator. Mine has 12 fins per inch like yours. WELL so much for that idea ;) Kinda glad since I don't have $1000+ to replace the core. Definitely going to check the radiator with the UV.

No doubt different people have different definitions of "overheating", and of course there are degrees of overheating. Just in my own mind, the coolant doesn't have to boil to say the car is overheating. I'd say a car has an overheating condition or propensity if the cooling system is unable to recover from a temperature excursion and in a reasonable time return the coolant temperature to normal, however you'd like to define that.

Just curious. How far away from the radiator is the fan?

Very good question Kev! There was a rule of thumb we used to hear, if you halve the distance you quadruple the air flow - I suppose that has some diminishing returns factor to it, but if the fan was more than 1 inch from the core, I'd consider making a small spacer - most fan to core distances I've measured are about 7/8, give or take.

I'll check. I agree good idea.

The fan is 7/8 inch away from the radiator.

That sounds within spec.


Has the radiator been flow tested?

Check the vacuum advance on the distributor. Also the mechanical advance inside of the distributor. If the ignition timing is too late at crusing speed it will cause overheating.