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

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Don't worry Bob, I'm here with you on that. When I was in the auto parts business I had some many people wanting a "160 degree" thermostat because their vehicle was overheating. I tried to tell them time and time again that it won't stop it from overheating but no one listens to a stupid parts guy.

!!!!Just because you have a 160 degree thermostat doesn't mean that your engine will maintain a constant 160 degrees!!!!

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You're absolutely right there. I've never heard the "too many fins" argument, that's a new one for me!

Just to clarify... the generic thermostat I picked up at NAPA which corrected the overheating problem on my '50 corrected the problem not by switching from 180F to 160F, but in replacing an old thermostat that barely opened at any temperature. I do understand that all the thermostat does is restrict the flow until the rated temperature is reached... that's all it does. I switched from 180F to 160F because that's what the books recommend and I had to pick one or the other.

Fin count: from 34 Eight - 12 per inch.
from 36 Twelve - 12 per inch.

Fin count: from '50 356 - 12 per inch.

!!!!Just because you have a 160 degree thermostat doesn't mean that your engine will maintain a constant 160 degrees!!!!

I just want you to know I fully agree with this statement in that a 160 thermostat will regulate the minimum temperature to 160. It will not prevent the engine from overheating. It does help cool since it restricts flow of fluid thru the radiator so it has time to cool off.

My thought of changing to a 160 degree thermostat is to see if the resultant engine temp goes down to 160 degrees or remains higher. If the the engine stays over 160 after the change than the cooling system is not good enough for whatever reason /radiator/pump/clogs/transfer tube/ blown head gasket.

I checked the entire engine with a UV temperature sensor/gun and the numbers all jive with the gage. The thermostat housing was about 180 and the front and back of the block were within 5 degrees of each other. When the gage went a little past the vertical then the UV temp was around 190.

When the engine overheated the gage was at full travel within a few (5) minutes and no it never went down.

Thanks for the fin counts sure would be interesting to see if the rad guy was right or not. Will let you know when I get the count.

We are getting snow again so I don't know when I can overheat the beast again and take a uv temp to see how hot it is.

OTG

Next time you have the temperature gun handly, pull the upper radiator splasher and check across and down the radiator. Of course you should find a good differential (perhaps 25 degrees?) top to bottom, but look for hot vertical "columns" not necessarily but possibly starting at the top which would indicate clogged tubes.

That would be one sure fire way to see if there are any clogged tubes in the radiator. Thanks for the suggestion.
Last thing I would have thought of.
OTG

Good suggestion. I would have never thought of using a temp gun like that to check for localized restrictions in a radiator. You do learn new things everyday!

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I agree with this. That is why if you remove the thermostat the engine will tend to run hotter. The system needs the restriction to slow the flow thru the radiator.

Almost thru that in myself before but felt I was being way to winded with my speech.

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All things being equal changing to a 160 degree from say a 180 degree thermostat will not change the engine temp at all. This does not mean the cooling system has anything wrong with it. The best gauge as to the status of the cooling system is weather the thing boils over on a really hot day or not. If you can drive at say 40 MPH when the outside air temp is 100 degrees without loosing water out the overflow tube you don't have a problem no mater what the darn gauge says.

Note: a blown head gasket alows coolant to be lost by it being ingested through the cylinder and dumping it out the tail pipe. The engine overheats because of the loss of water not directly because the head gasket is blown.