davidf59

Hi all. I have a problem I've been scratching my head over.
1959 with a crate 350 small block.

When I get done driving the car, short distance, no issues. Nothing leaks.
However twice I've driven for a fairly long drive, somewhat constant 65 mph. When I get done the antifreeze spews out the overflow tube, about 1 qt, maybe a bit more. It's happened twice.
Doesn't appear to happen while driving. Stopping at stop signs/lights I don't see anything, however I haven't looked all that hard.
Short drives, or drives under a constant 65mph doesn't cause any issues.
OH - 1 more thing. Temp gauge reads under 180 (160-170 or so).

I'll probably end up putting in an overflow tank. But still - these symptoms just don't seem right.

Thoughts anyone? Where do I start looking?

Thanks
David

Powershift

What type of radiator do you have?? Normally the radiator or expansion tank is not filled to the top, but has an air space of at least a few inches above the coolant level. You fill to this level when cold so that when the coolant expands with heat it doesn't overflow thru the radiator cap to the ground.

I would also check the cap to be certain that it holds the correct pressure on the cooling system when hot.

Larry

Jud Chapin

And how's the condition of the rad and other cooling system parts?

davidf59

All the parts seem fine. Seems to cool with no issues. I just find it kinda odd that it only happens when constant driving at high speeds. I do notice when sitting in traffic on a hot day the temp climbs a bit - hitting 180-185. But once I start moving the temp drops down to normal (or what I consider normal...).
Car was restored by someone else. Type of radiator is a good question. I don't know if there are markings. Worse case I'll post a pic.
Thanks guys.

MelWff

Does the radiator have a cap on it?
If it has a cap, when completely cold, how much airspace are you leaving above the fluid level. You should not be completely filling it.

mvftw

Pull or replace your thermostat...then see what happens...

davidf59

The radiator fill has a goose-neck so you really can't see the 'water line' in the radiator. Likes like this.

Powershift

OK........then how far up to the overflow point do you normally fill it??

I would fill only until I saw a water level in the very bottom of the gooseneck turn. This should leave a few inches of air space. If it still overflows after this, just let it alone for awhile and monitor the engine temperature. It should seek its own proper level after a few heat/cool cycles.

Larry

-sinner-

When you shut your car down, it actually gets hotter than when it is running, since the block holds heat and continues to transfer it to whatever coolant is inside without the benefit of that water circulating through your radiator and giving up that heat. If your water temp is reading as low as you say, something is wrong. Check these things: is your radiator cap lined up to allow free flow of coolant to the expansion bottle? And holding pressure? Is your system overfull? Open up the radiator when it is cool, fill to where you can see the coolant covering the cores by about 1/4 inch, then put the cap on and fill your expansion bottle to the full cold line (don't have one? just fill it about 1/4 of the way up). Now start your car and let it warm up to operating temp, and top off your expansion, if needed, to the full cold mark after shutting her down and letting it cool off. When you installed this crate motor, what was the temperature rating on the thermostat you put in? And is it working? You can heat some water to that temp on the stove (use a candy thermometer) and see if that opens the valve on your thermostat. Or just replace it with a 190 degree thermostat that you have drilled an eighth inch bypass hole in the flange on. Don't get any metal bits in your motor, and make sure the hole is fully inside the water passage. This just makes sure you have some water circulating before and after the thermostat opens, or if it fails. Good luck!

BobT59

Years ago I put a 327 in my 59 and experienced the similar problems but worse. It would pick up heat at a stop light but never lose it to the point of boiling over.
I tired everything...flushing, new radiator core, etc but nothing solved the problem until I put in a Dewitts radiator about 4 years ago...best investment ever.

Ran like an ice cube but when topping off the new radiator, it would gurgle and burp out a quart or less...seems natural when the engine heat built up and the car cooling system is shut down.

Even so, I added the coolant recovery system from 62 and it "gurgles and burps" into the expansion tank and not on the floor.

Sounds like your issue is the natural expansion of coolant after shutdown. Try leaving it like that and then run it...based on what you describe, my guess is you will experience normal operation and cooling and no more fluid on the floor....

PS: I run it without a thermostat and yesterday, in 87 degree heat it ran about 160.... great radiator..

MelWff

read this thread
https://www.corvetteforum.com/forums...lp-needed.html

59BlueSilver

ohiovet

If you drive the car after it pukes and you do not add antifreeze what happens?
Does it run hot?
Does it puke any more fluid.

davidf59

OhioVet - I did run it home without adding any fluid. Kept an eye on the temp gauge. Drove it about 40 miles at highway speeds and the temp maintained 160. Got home and nothing seemed to spit out.
Apparently shorter drives at less than highway speeds doesn't heat the engine as much as the longer, high speeds.
I'll keep the fluids where they are continue to monitor the temp.
Also think I'll add a coolant recovery system to the car.
So - slight different question- has anyone added recovery system to a C1? Where/how did you mount the tank?
Thanks all for your feedback!

wraplock

It sounds to me like you have simply been overfilling the radiator, you must allow room for coolant expansion. When your coolant reaches operating temp the coolant expands and the internal pressure increases. If the pressure reaches the limit of your radiator cap if working properly the cap will allow the system to vent spilling coolant out and releasing pressure. A simple cure for your radiator without the Corvette expansion tank would be to install a cheap recovery tank. Fill the tank to the low level and if your system builds pressure it will catch the fluid and then allow the system to draw back coolant from the recovery tank as needed. Napa or most auto parts store as well as Summit sell these kits. I installed one on my hot rod 56 Chevy and problem solved.

http://www.oreillyauto.com/site/c/se...0186/C0331.oap

Don

BobT59

Like I indicated in an earlier reply, I added a coolant recovery to my 59. Got it from Zip Corvette.... pretty straightforward and easy installation...the tank mounted on the driver side exhaust manifold... had to cut and tap into the radiator drain and run the rubber hose over to the expansion tank... another hose runs from the expansion tank to drain.

I had a 13 lb cap on the radiator and I left that on... I think the one that came with the expansion tank was a 7 lb... filling the tank to the line indicated on the tank fills the radiator all the way.... don,t fill past the line otherwise you will just gurgle and burp it out...

works great...

GTOguy

Classic example of an overfilled cooling system or bad radiator cap. Make sure system is not overfilled and cap passes a pressure test. I prefer 15-16 pound caps.

davidf59

BobT/GTOguy - Good idea on the radiator cap. I'll check it as well.
Again - THANKS all.

ohiovet

David,
It sounds like your engine just puked out the excess coolant.
I did add a catch can to a modified 57 Corvette. Mounted it on the right side of the core support . The can had a fitting on the bottom to allow the excess fluid in and upon cooling the fluid was sucked back into the radiator.

BobT59

David..

here is how my expansion tank is set up.... mounted on the driver side exhaust manifold




If I remember, the only thing that did not come with the kit was the 90 degree threaded elbow from the top of the water pump...also available at Zip