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

Many hotrodders remove the thermostat, but they put a brass plate with a hole in it to replace the stat. It is called a restrictor plate and the purpose is to slow the water traveling through the system to allow it time to absorb heat and then get rid of the heat in the radiator. If the coolant runs by too quickly it cannot do its job.

Here is neat trick to use when running an engine without a thermostat. Simply take a thermostat that fits the engine (opening temperature is unimportant) and remove the working parts, leaving only the outer ring. Install this outer ring as the restrictor where the thermostat normally fits. This is a more satisfactory solution than trying to find the right size washer. Removing the thermostat will only work around the overheating problem and is not a real fix; however, it may help.

Engine timing is very important. My first National meet 475 miles from home our Deluxe 8 developed a overheating problem.I changed thermostats, had the radiator flushed, replaced belt, installed new cap and was ready to replace the head gasket when a old timer came by and told me to start the car and then asked for a screwdriver. He told me the timing was off and he reset it by ear. The car performed fine the rest of the week.
Good luck

Packardtaximan,

Engine timing is very important.

Timing? Are you suggesting that if the spark is advanced TOO much, it can contribute to overheating?

DanL

Retarded timing can be a cause of overheating.

Jay writes,

Quote:


What i've been told about why an engine tends to run hotter with the thermostat removed is that the restriction created by the presents of the thermostat slows down the coolant thru the radiator allowing more heat transfer to occur. Without the thermostat there the coolant tends to travel too fast thru the radiator thus giving up less heat and delivering the coolant back to the engine hotter than it could be.

Clipper47 writesQuote:

I was always under the impression that just the opposite is true. Timing that is to far advanced tends to cause the engine to run hotter. I seem to remember one car I had where the timing was advanced to the point it would ping on a hill. When the timing was brought back down to get rid of the pinging the car seemed to run cooler too.

It's retarded timing that causes an engine to run hot. Overly advanced timing is often characterized by preignition and possibly failure of the starter motor to turn easily.

Advance the timing about a degree and try it. Don't forget that timing changes as the points cam follower wears. My 49 was beginning to run hot and I found the timing had changed over 2 degrees.