I rebuilt the 292 Y block in my 64 Ford pickup, it now overheats. I have checked the thermostat, it is working correctly. The radiator has been flushed. I confirmed the headgaskets are correctly installed. The timing is set at 5 degrees initial and the centrifigal seems to be coming in correctly. The radiator seems to have good flow when the thermostat opens but after a few minutes it starts getting bubbly then boils over. It will only idle for 15 to 20 minutes before overheating. The heads and block were both milled flat, little material was removed so the compression should not have changed much. The motor went together well, all the tollerances were in spec. The guage is only showing 185 degrees but a second thermometer is showing 200+.

Any tips would be appreciated. I was hoping I wouldn't have to take it apart again.

Confused.

Assuming everything you have said has been done correctly, then how about cracked head? can you get chemical head check done, it is a clear tube with blue liquid that reacts with ex gas, it sits in radiator top and basically inhales any gas in the cooling system, which obviously shouldnt be there.and turns green. keep in touch! how about a little more timing also.

  AussieBill            YYYY    Forever Y Block     YYYY

 Down Under, Australia

I think Bill is probably right. If you get a big burp of air in the radiator and it then overflows you must be be getting air from the compression cycle leaking. What head gaskets did you use. I always retension all head gaskets after the engine has run for a short time. This may stop the leak. Did you deck the block.

Regards

Rick - West Australia
Do Y Blocks Downunder run upside down? Gravity Sucks!!

Sorry didn't notice you milled the block as well.

Regards


Rick - West Australia
Do Y Blocks Downunder run upside down? Gravity Sucks!!

I had the heads and block checked for cracks.......but that doesn't mean something got missed. Thanks for the tip on the gas checker, I will give that a try. I had planned on checking the valve lash again and the head torque after 500 miles, I will do that now and see what I get.

Thanks for the help.

Four of the long head bolts are longer than the other six.  The longer four go in the end holes of the heads.  If a longer bolt is installed in a shorter hole, it will bottom out and not clamp the head gasket, causing a compression leak into the cooling system.  The difference in length is about 1/4".

John - "The Hoosier Hurricane"

The gas checker that Bill mentioned is dead on. Fastest, easist way to check for that type of problem.

Dan      Kingman Az.      86409