Got a 62 super 88 394 that is over heating I have tried orginal rad and electric fan then added orginal fan blade. Car idles to 210 plus and when shut off pukes out anti -freeze out the over flow. Then tried new aluminum rad and electric fan same thing happened. Then tried aluminum rad and 7 blade fan and the same thing happened. It has rebuilt water pump looks good not sure how to check it out. Does anyone have any ideas Thanks

 

Hi Eric, just wondering if you still have the original frost plugs, I found that when I removed the plugs and flushed the block removing all the rust and scale from around the cylinder walls and replaced the plugs with new ones the coolant flowed better and the engine ran cooler.The rust and scale won't allow the coolant to flow and the cylinders heat up.
Steve

 

How much antifreeze pukes out after you shut it off ?
If it is a small amount, , then it is probably due to the cooling system being overfilled .
That's right , the systems without the coolant recovery bottle were never supposed to be entirely filled when cold.
The Olds service manual calls for a level of 1/4 inch below the top of the filler neck AFTER the engine reaches operating temperature.
As you can imagine, this means that the level when cold may be at least an inch below the filler neck.
A good idea is to add a recovery bottle. One from a 70 or later car might work. Or they sell aftermarket recovery bottle kits too. Make sure you also have the proper radiator cap for a recovery system.
Then you can fill the radiator plumb full and the recovery bottle to the "cold" line .

 

Like was stated above it's probably overfilled. 210 is not abnormal if the car has been sitting there idling for a while on a hot day. What is the temp while driving? What temp is the thermostat that was installed? And what temp is the gauge reading while driving?

 

Good advice so far.
Have you tried a cooler thermostat? One that opens at 180 degrees?
Also, if you do not have a surge tank, you need an old style radiator cap that holds higher pressure. Fusick sells the correct originals.
However, since you have an aftermarket radiator, I might add the surge tank, like suggested above.
I added one to my '68 Toronado, and no more puddles.

 

The motor has been rebuilt everything is new. Great idea for the surge tank thanks. Car only needs to run 5 to 20 minutes before heating up. Car runs about 190 when on Highway running a 160 thermostat in the car now.

 

Sounds normal to me, the 160 temp rating on the thermostat is the minimum operating temp. The upper level temps are controlled by your cooling capacity.

 

Have you resolved the problem? What was the solution?

Agree you have either a blockage in the engine or the wrong radiator cap.

 

don't have the problem fixed yet
does anyone know what the max you can bore a 394 engine before the cylinder walls are to thin thanks

 

I've seen guys bore them out to four and a quarter inches and run them at a dragstrip. That's 418 cubic inches at the stock stroke.
Jahns Pistons (out of business) used to make 4 and 1/4 forged pistons for 394's.

 

problem still there went about a mile in the city the other night and car went up to 230 when i got to my destination. Still working on it

 

Doubtful its a bore and piston problem sounds more like a blowen head gasket but what is your logic on taking it out that far for a heating up issue or did you do this already do this and are afraid its to thin? 394's can be bored way over 100 thousands without problems if you can find pistons. Eggie machine may be able to make you something if you have to go there but I would explore other things first....Tedd

 

At the Grand Rapids cruise show I noticed many overflow bottles improvised from AL water bottles, plastic water bottles, etc.

 

Are you running a fan shroud with the 7 blade fan?

 

Thanks for all the info I have been working on it over the winter and I think it is finally figured out will know soon. Had to reset timing, new flex fan, adjust operating temp so electric fan kicks on and add a pressurized overflow tank with new rad and a shroud.

 

You've got many good ideas to explore. Here are a few more.
Put the thermostat in a pot of water on your stove with an accurate thermometer. Verify that it opens completely when it's supposed to.
If the problem started after the rebuild, check the leaking head gasket possibility as suggested. Also some rebuilders will set tolerances a bit on the "tight" side which can generate more heat.

 

One thing that causes over heating is incorrect timing. Even though the timing is set properly with the marks it can still be wrong. I had to rebuild the vibration damper on both my 1961's because the dampers had failed. The crankshaft pulley is bolted to the crankshaft. The vibration damper is mounted to it with vulcanized rubber. Over the years the rubber fails and the vibration damper slips. Consequently the timing marks move.
The only way to check this is to find top dead center on compression stroke on number one cylinder and see if the timing pointer points to TDC. If not, the damper has moved and the timing marks are no longer correct. You can mark TDC on the crankshaft pulley as I did and time the engine to that mark if you don't want to rebuild the damper.
Surprising how much better and cooler the engine runs when timing is corrected.
My dampers were so far off when at TDC you could not see the timing marks.

Hope this info helps. Good Luck, Dave