dale3in98

Sorry, for asking another question about overheating/boiling over/radiators, but I can't find the answer/help that I need using the forum search.

First, just getting the car back on the road and trying to work the bugs out after restoration. Here are the car specs:

1959 Corvette 327 4 speed, Holley 600 Carb, HEI Ignition, Manifolds,
New Dewitt Aluminum Radiator with a 50/50 mix of Dexcool/distilled water, new high flow water pump, 180 stat, dual electric fans and a Wells temp sender.

Symptoms:

After several drives the car has been puking coolant...especially when I stop and just let the car idle. It doesn't puke alot of fluid out, but it seems to do it everytime I drive it. Temp hand stays around 190 and the fans kick on at 180. I thought after several drives the car would've leveled the coolant level off on it's own.

Questison:

Any idea why the car is boiling over?

Should I invest in an overflow tank/can?

How much coolant should be in the radiator and how can a measure
the coolant level?

Any help, ideas, or suggestions would be greatly appreciated. Anxious to enjoy the car but I'm afraid to drive her very much.

Mikey1

Small block systems were designed to have an overflow tank.....

....if your replacement radiator has got a reservoir....then this might not be the cause...otherwise...add the tank and things will be ok.

wesmigletz

A bad radiator cap will allow the radiator to puke coolant.

Coves4me

Dale,

Try these.

1. Check initial engine timing....advanced = cool; retarded = hot. Check your vac advance for proper ignition advance.
2. Check carb jet mixture.....read your plugs. Tan to dark tan would be acceptable range.
3. Check for vacuum leaks at carb and manifold that may cause a lean fuel condition and allow engine to run hot
4. Radiator cap? Try a new 16-pound cap instead of original 7-pound.
5. Close all gaps around the fan shroud, radiator, and radiator support
6. Check the thermostat to make sure it is opening properly with an IR gun on the housing with engine idling; or remove thermostat and heat it in water on the stove with a thermometer
7. You say you are running a "high flow" water pump. It's possible that it is circulating the water to fast for it to absorb all of the engine heat. You might try a standard water pump if all else fails.
8. Heads torqued down properly? Possible water leak into a combustion chamber that is pressurizing the system? A long shot, but a blown head gasket or warped head can do this.

Good luck.

John McGraw

You may be just filling the radiator to full. Later C1 corvettes had an expansion tank to take the excess liquid that came out when the coolant expanded due to heat. Try this, next time you drive the car, do not refill the radiator when it pukes and see if it pukes again the next time you drive it. If not, then problem resolved. If it continues to puke then I would look at a weak radiator cap. Chances are that you are just filling it too full and the coolant has to have somewhere to go when it heats up. The radiator will have a pocket of air in the top of it when it cools down, but will displace the air when it heats up.
Regards, John McGraw

dale3in98

Thanks for the suggestions. I haven't refilled the radiator since the initial filling and have driven it about 6 times. It has puked coolant each time and that's my concern about the proper fill level. On a 59, due to the filler neck, you can't tell how much coolant is in the radiator. Seems that after 6 drives the coolant should be leveled off right?

As for a overflow tank, would one of those hot rod tanks work? I think the vary from 2 to 3 around and 10-17 inches in length. Next problem is where to mount it?

Ironcross

You are running a correct temperature stat at 180 degrees, but two things I wonder about is the pressure cap and possibly the so called high flow water pump circulating the coolant too fast. They really are not necessary. However I have no problem with the rest of your system or the other members posted observations.

0Tom@Dewitt

I agree with John M, I think you just have too much coolant in the radiator. You aren't going to "boil" until you get over 250 with a 50/50 mix. You might have a bad cap, but I doubt it. Drain out a quart and start again, if it dumps it out again, change the cap. 190 isn't a problem at all, so I wouldn't worry yet.

kabong

I got a overflow tank out of a S10 pickup, hid it under the right front fender, under the headlite and it's setting on the bumper support...works slick. I woud try this first. Fill the radiator up cold, but some sort of expansion tank on it, run the tank empty, and when it pukes, it will spit it into the tank...should be about right. Works for my 60, with the 230 hp.

dale3in98

Ok, finally got to drive the 59 today with a new 16lb radiator cap. The previous cap was new also, but was 14lb cap. I drove the car about 50 miles stopping periodically to check and see if she was puking coolant...no puking observed at all today. So, maybe it was the cap after all.

However, my temp gauge leveled off about 180-185 for most of the trip and then steadily increased to the 200 range, which made me real nervous. I've tried 3 different temp senders and thought the Wells unit was the right one until today. The temp sender is inserted into the top rear of the intake manifold. I checked the sender with a temp gun and it read around the 175 area. Water neck, radiator and inlets outlets all read lower than the temp gauge in the car. I did send the temp guage off and had it cleaned/recalibrated.

Question: Doesn't anyone make a temp sender that reads correctly? Would it be best to just run an aftermarket mechanical unit?
Anyone else have C1 overheating,temp sender, and faulty guage reading problesms?


I know we've beat this issue to death, but it bothers/worries me sick thinking the car is overheating.

Coves4me

Dale,

I am a relatively new member to the forum, but I've read a lot of posts related to this overheating issue. I am of the opinion that the gauges are marginal at best, the temp senders are close but not accurate, and a good ground is everything in these cars. I have a 59 that I will leave as stock as possible as I do not drive it much, but my 62 is being readied to be a fun driver that my wife and I can enjoy "reliably". Witha basically new cooling system, pump, aluminum radiator and proper specs it still acts like it runs hot. As such I have purchased a new thermostat housing with a temp sender outlet, a Cyberdyne digital temp gauge to mount under the dash, a 160-degree thermostat, and I'm searching for an upper radiator hose that will make the new vertical outlet housing work with the stock radiator. I'm hoping that this will solve my reluctance and apprehension to enjoy my car. Yes, it won't be stock, but the piece of mind it will give me is worth it. When I find the proper radiator hose that works, I will post the part nos. for others to use. Hope this helps.

John McGraw

Dale,
Your gauge is only 10 degrees off, You don't get much better than that!
These were not precision instruments by any means, they were just meant to give you a realtive temp. Like Tom, I doubt that you cap was the culprit, since at the temperatures you are running at, you should be able to run without a cap and not puke. The coolant is not going to boil over until close to 220 degrees. Most likely, you have now purged the liquid out that is now necessary to allow for normal coolant expansion when hot.
Regards, John McGraw

dale3in98

Coves4me...I'll be looking for those part numbers and piece of mind.

John McGraw-I actually added about a quart of coolant/water to the radiator and then replaced the 14 lb cap with the 16 lb cap. For now, it appears as though the cap was the problem. After some longer drives I'll be able to determine more.


What is a good operating target temp for a C1?

vettes1st

It should run at 180' if everything is working correctly. Somebody posted about running a 160' thermostat. That will do NO good at keeping the car cool. People have been trying this since time began and they still don't understand the function.

Coves4me

vettes1st,

You are correct about the 180 degree thermostat, but I'm in Dallas where our summers reach 100 degrees+. As an old late-model Mustang fan, we would install 160-degree thermostats in the engines to trick the computer into thinking the engine was cooler and needed to be in choke mode. This would fatten up the mixture, let the engine run cooler in the summer, and boost performance. Unfortunately, gas mileage tanked and emissions suffered, but the end result was a car than ran a lot better.

I understand the trick won't work with the Vette, but I'm hoping the engine may run a cooler.

By the way, where's Kingston? My wife is from Kingsport in East Tennessee and we lived there for 7 years back in the 70's. Nuthin' like the Smokies in the fall. I'm hoping to drive the Tail of the Dragon in NC one of these days. It sure would be sweet in my 59.

dale3in98

Ok, here is the lastest...Changed the cap from 14lbs to 16lbs, topped the radiator off, and added a mechanical temp gauge. Drove the car over 150 miles. The car stayed between 180 to 195, until I drove up hill, stopped at a traffic light, or slowed by traffic. The temp would slowly creep up to 210. Radiator didn't boil over or puke any water.

Any suggestions on why the car still wants to run hot, especally in traffic. I know these cars do run hot, but with a new Dewitts radiator, water pump, 180 stat, and dual electric fans...shouldn't you be able to drive in traffic, hills, etc. without hitting 210 temp range?

Would a 2.5 inch exhaust lower the temps...I currently have a 2 inch system?


Anyone use the Red Line Water Wetter? Does it work or is it a waste of money?

jerrybramlett

Stock '56 - '67 small block Corvettes did not run hot when they were new. Yes, I'm old enough to remember first hand.

I don't like your electric fan set-up, and you've made no mention of which shroud you're running. Some electric fans block more air than they push or pull.

If it was my car, I'd duplicate the stock '62 Corvette fan/shroud set-up on it. This means a five blade Corvette fan within the short, full-circle design metal shroud. I'd also make sure the 3" tall open area just below the radiator was blocked off. Also, your pulleys on the crank and water pump must be the same diameter.

I think you should forget trying the miracle cures like Water Wetter or Ring Job in a Can.

The myth of "water moving too fast to cool" is a crock at street speeds. Wait until you run flat-out at Bonneville to worry about that.

Coves4me

dale3in98,

Me thinks you are OK, but you don't trust the Temp gauge. The first thing I would do is add a Cyberdyne Digital Gauge under the dash to see within 1 degree what you're really running. Without the radiator hose that you will need to find, here's the part nos. to add digital gauge:

Cyberdyne 2-inch dia. Temp Gauge #A020E060N Summit Racing
Cyberdyne SENSS6E temp sending unit Summit Racing
Cyberdyne 2-inch dia. Volt Gauge #A000E060N Summit Racing
Auto Meter Black #2237 dual 2-inch gauge mount panel Summit
Murray #84908 cast iron water outlet with threaded outlet for brass fitting and sending unit O'Reilly's Auto Parts

The radiator hose will need to have a 90-degree bend at the thermostat housing to work. I've been too busy building my tranny to look, but I'm sure there is one that will work with some minor trimming. Good luck.

dale3in98

Since I am running electric fans, I'm not using a shroud...didn't think one was needed/required with the electric fans. They are "puller" fans rated at 2400 cfms combined. The fans kick on at 180 and operate fine.


Coves4me-I didn't trust the factory gauge so I installed the new stewart warner also...both gauges show the same to 180...then the factory gauge is about 15 degrees cooler. If the new guage is off, I don't think it is by much. Thanks for the part numbers, if I don't get this figured out I'll have to try your setup.

JohnZ

If the electric fans are just attached directly to the back side of the radiator, they are only pulling air through the portion of the core covered by their diameter; the rest of the core not covered by the diameter of the fans is doing nothing in stopped or slow traffic. With the factory fan and shroud setup, properly edge-sealed, the fan is pulling air through the entire core, edge-to-edge and top-to-bottom, including the corners, so every square inch of the core is working to reject heat.

You also haven't mentioned what kind of distributor and vacuum advance arrangement you have, and what your timing map looks like - initial timing, how much centrifugal advance and when it stops and starts, is vacuum advance connected to full manifold vacuum and is it working properly, etc. Retarded timing and/or inoperative vacuum advance or vacuum advance connected to "ported" vacuum instead of full manifold vacuum has a MAJOR influence on idle cooling. If you can fill in the blanks on your ignition setup we may be able to help you further on the idle cooling problem.