1969 road runner 383.

[Kmart]

Runs good for about 30 minutes then starts overheating. Origonal #2949053 radiator. This is a origonal numbers matching mopar. Trying to keep it origonal. Any suggestions. Radiator seems to be flowing right. But haven't had it in a radiator shop. Not many good shops lift. Everyone what's to sell u a new one. Any ideals. 22inch radiator with auto trades. No a/c or power anything. Basic car , no extras.

 

[BeepBeepRR]

Do you have a fan shroud? Is the clutch fan in good shape? If the clutch is worn it will not spin faster at higher rpms hence not cool the engine.

 

[69SuperBee451]

When does it overheat? In traffic? On the freeway? Higher RPM?

 

[dadsbee]

My 383 Bee runs on the stat... 053 rad, fixed 7 blade and no shroud

 

[Kmart]

Do you have a fan shroud? Is the clutch fan in good shape? If the clutch is worn it will not spin faster at higher rpms hence not cool the engine.

No shroud or clutch fan.
Old school. 1 belt. Factory new no fan or clutch type fan.

 

[Kmart]

When does it overheat? In traffic? On the freeway? Higher RPM?

Higher rpm 60 mph. DOESNT GET HOT IDEALING.

 

[69SuperBee451]

Higher rpm 60 mph. DOESNT GET HOT IDEALING.

After 30 minutes? What does your timing look like? Base and total? Factory AVS?

 

[pnora]

Higher rpm 60 mph. DOESNT GET HOT IDEALING.

Run a laser pyrometer over the fin tubes. Most likely it has plugged tubes. A shroud could help.

 

[lewtot184]

I did something last summer that helped my small radiator/big block cooling. I pulled the radiator, layed it horizontal in the sun and filled it with a couple of gallons of 5% vinegar and waited a few hours. Flushed everything and i think it took 10 or 15 degrees out of the engine temps.

 

[6PKRTSE]

Cracked block, blown head gasket?