1968 225 slant 6 overheat
 

Hi everyone.. thank you in advance I have a 1968 fury 1 with a 225 slant six. i can drive the car around the city and it seems ti be fine but when i get out on the highway 65 mph it overheats.. I replaced the water pump and thermostat flushed the rad and block checked timing and it is at 0 compression seems to be 120-125 across all cylinders. at highway speed i measured 248 degrees.. any ideas where to go now? someone said that it problably just tired. my email is gmaat@shaw.ca thanks

Hockey -

Make sure your fan is moving air in the right direction.
That's the opposite of what usually happens.

There was another thread on this topic a little while ago you might fing helpful..

Archer

Thanks archer. I have the original 4 blade fan and it pulls a lot of air through the rad. I check previous posts as well.

measured with what?

A digital heat gun. It seemed to be pretty accurate. The thermostat housing was reading 184 when the t stat opened.

Timing @ zero, it's been a very long time sense I've I slant six but that does not seem right. Use your temp gun to check you rad. and see if it's at temp all across the cooling surface, if not could be plugged. Finally made sure the rad is full of coolant, hoses are good not soft, rad cap is good etc.

I would recommend that you use a water Temp gauge and see what it reads....
Also.... Add 6-8* of timing.... And Make sure the Advance is working in the distributor.....
Fan Shroud is on the vehicle?

:)

Thanks cowboy. I'll try to advance the timing s bit. The vacuum advance is working. And there is no fan shroud. I don't think they ever came with one. All the hoses are new and the rad is full.

I am sure it had a shroud at one point...... Not that is 100% the fix to your problem, But it will contribute....

:)

Fan Shroud & Timing
 

YEP !! - The timing and a fan shroud may be the fix.