I have a '56 F-100 with a 351 Windsor, .030 over and a mild cam. The engine has about 2,500 miles on a complete rebuild, done by a certified mechanic and myself. The problem is the engine block gets extremely hot and the oil pressure drops to about 10 psi. If I shut the engine off it will not restart until it cools down. The coolant temperature runs about 180 to 185 degrees. Presently running 5W30 oil in an 8 quart oil pan. Thinking of trying 30 weight and/or an oil cooler. Any suggestions?

 

Welcome to the forum. When does it "run hot?" The temperatures you mention is not that hot. What kind of a gauge are you using? What kind of radiator? Radiator known to have good flow? We need a complete description of what configuration you have. An oil cooler will help carry heat away from the engine.

 

10 psi at idle? What's it like at various points in the operating range? A pressure drop is normal since oil viscosity decreases at hotter temps. Synthetic oils are affected less by temp.

Like raytasch said, 185 coolant temp isn't too hot. It's actually too cold for efficiency.

 

I agree, 180-185F on a new engine is great. I don't know how your engine block can be unusually hot if your coolant temp is normal. Engine not starting when hot could be caused by several things, like bad starter, bad coil, weak battery, timing too far advanced, etc. I think we need more information to advise further.

PS, Welcome to the forum!

 

I agree with 52 merc on all those points, we need more info

 

The 351's were not designed for 5w30, especially in Florida's temps. 10w30 would have been spec'd. Why are you running 8 qts?? With that much oil, it's essential you get the engine above 180 for extended periods to drive off condensation.

 

Yes, please more info fatfenderford. What carb are you running with the engine?

 

10 PSI at idle wouldn't necessarily concern me, but on a new rebuild unless he running race clearances, it seems low. none of my motors have less than 25 lbs. at idle and most are far from being fresh. 185 degree temperature is not an issue.

 

Here's the information all of you ask for:
Raytasch: it runs hot if I let it idle ( without driving it) and when it's under power. I'm using an auto meter (non-digital) gauge and a new Gibson aluminum radiator that is sized for the 351.
91 F-Body: operating range of oil pressure is 55-60psi at start up and drops to about 10 psi as engine heats up. Oil pressure if I let it idle (not driving) follows the same pattern. Idle when hot after driving is about 10 psi. When engine is under power (normal driving) this will happen in about 10 minutes time.
52 Merc: there is a new high torque starter, new coil, and a new battery. I just had the timing checked recently.
Carb is a Barry Grant 4 barrel.