Overheating

packyusmc

packyusmc

Member
i have a '38 standard w/ '48 engine stock but with Offy heads and 4bbl. Intake. Since I've had this car I have had the radiator rebuilt, 4 core. Have electric fan with surround, Schumann 180 thermostats, overflow tank. 7 pound cap. It still vapor locks. Could it be a weak fuel pump? What else can I do? Thanks, John
 
Electric fuel pump.

Overheating normally implies high engine temperature, any idea what the engine temp is running? Or is the vapor lock the only issue? If it is just the vapor lock, it is most likely the fuel, but the electric fuel pump should help that if it is mounted near the tank and down low.
 
Wooden clothes pins on your gas line between your pump and carb...don't laugh it works
Randy
 
The mechanical fuel pump vaporizes the modern fuel. Electric fuel pump as others have advised.
 
Yes, I do have a spacer. Have Bob Drake water pumps that were on the car when I got it. I use 100 percent gas here in Oklahoma. I quit using clothes pins about 1965. I do have a hand held thermometer but forgot to use it. I know that I should get an electric fuel pump but have been trying to put that off. It will stop running with temp at 180 going down the road. It will refuse to start after a short stop, like to get gas. It will start again when then temp. Is back down to 150 .You are right, I need to get an elect. Pump but would really like to know what the real or underlying problem is.
 
may I suggest adding about 4 ozs of MMO.to each tank fill up ,or even a little diesel see if that helps .
 
Make sure it is not getting fuel. A bad coil or condenser will do the same thing.
 
What's the old saying? Most of the fuel problems are electrical. I also would check the coil or condenser. When it quits, pull a plug wire and see if you have spark.
 
Also could attach a fuel pressure gauge to see if there is fuel pressure when the suspected vapor lock occurs.
 
180 isn't that hot but vapor lock is a pain in the butt with mech. pumps, go electric and make sure your fan is either pulling or pushing depending on how it is set up. i run a larger electric fan, pulling, and i never overheat.
 
packyusmc said:
i have a '38 standard w/ '48 engine stock but with Offy heads and 4bbl. Intake. Since I've had this car I have had the radiator rebuilt, 4 core. Have electric fan with surround, Schumann 180 thermostats, overflow tank. 7 pound cap. It still vapor locks. Could it be a weak fuel pump? What else can I do? Thanks, John
Click to expand...

Your pump could be weak but you need to put a "T" in the fuel line after the fuel pump so you can read it while running. As the pump gets hot the fuel pressure drops. At 1 1/2 lbs your getting into vapor lock when the pump gets hot. It starts with a fluxuation in fuel pressure. Gas starts to boil in the 130 degree range, vapors form and with low pressure stops pumping. Check the temperature on the top of the fuel pump, the temperature in the rear of your engine will get to 325 degrees. Your engine should run between 178 and 182 with the stats you have. Stats don't cool the engine and once the temperature gets much over 180 they are just sitting there wide open. A 4 lb pressure cap is all you need or you have a cooling problem. Your water pumps may not be circulating enough water. Fill the radiator up to the bottom of the filler neck. Does it cool better driving at 45 or 50 MPH?? If so your electric fan is not pushing enough air
through the fins. G.M.
 
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