VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1933-1936 still have overheating problems with my 34 chev

Hi there,
despite fitting a recovery tank, my chev overheats within 4 mins and the fluid bubbles out of the overflow tank big time.

I thought that maybe the tank was mounted to low for the natural process of vacuum to occur and suck the fluid back into the radiator.

So today, I remounted the tank on the bulkhead and reconnected the hoses.

Started up the beast and behold, within 4 mins it boiled and spued out the fluid from the overflow tank all over the engine...bugger.....

The engine was chemically cleaned during the engine rebuild (18 years ago) and the radiator was also renewed at the same time (new) so I am now leaning to the theory that the rad is blocked and the water is not being allowed to circulate?

What is your opinion on this matter?

I may have to remove the rad and have it cleaned out,now that is one very big job, remove headlights, unbolt guard bolts and many radiator cowl bolts and eventually lift out the rad core...I estimate at least a day and running into the next. Same for replacement.......OMG how did I get into all this in the first place?

as for the oil leaks see my next post.

Peter

Do you have the correct thermostat in this engine ?

You should be able to see fluid flow across the top of the radiator thru the rad cap hole. Can you ?

Open & remove the rad cap and let the motor run, its possible you have air trapped in the block or thermostat is not opening. Look to see in the water if your getting a lot of air bubbles.

The check for the thermostat function is too remove it and boil some water on the stove and place the stat into the water using needle nose pliars and watch to see if it opens and remove it and watch it close. Repeat to make sure.

mike

Many issues can cause overheating, but in your case I would bet on a stuck or defective thermostat. As a test, remove the upper outlet on the front of the motor and remove the thermostat. Clean the surfaces an cut yourself a cardbord gasket and reassemble. Replace the coolant and fire it up.

If this solves your problem, I recomend a new thermostat (180 deg.) and prior to installation drill a 1/8" hole in the mounting flange just inside the mounting gasket area. This allows the air bubble to pass from the top of the engine and also allows the thermostat to "see" what the engine is doing during warm up due to the trickle of coolant through the 1/8" bypass hole.
Good Luck !!
Jerry

Mike and Jerry

Peter,

After checking the thermostat without finding the problem, I suggest the following:

a. Check that the bottom hose is not collapsing .

b. While the thermostat is out, remove the top hose and fill with water. Start up to check for bubbles indicating one of the following:

1. Cracked head
2. Cracked block
3. Bad head gasket

c. Check with the radiator full of water. Rev up the engine, the water should not overrun (until it heats up) because the radiator capacity to take the water should be greater than the water pump can supply it.

d. Take both the bottom and top radiator hoses off. Use a garden hose to fill the radiator. The water should go out as fast as it comes in. Similar to "c" above. Now, put your hand over the bottom outlet and let it fill up. When full, take your hand off the water should spring out with a good gush of about 5-6 inches. Listen for any sucking sounds coming from the top of the radiator. Such sounds will be produced by partially stopped up flues.

e. If any of the radiator checks indicate trouble, then take it out and have it boiled and rodded. That means that the top tank is taken off and the core boiled, and with water running up through the core a flat rod (similar to steel strapping material) is run down through each flue to get it cleared up. Any competent radiator shop should be able to do it. If you end up with the radiator having a bunch of tiny pin holes on the flues, just add a little (half-tube) of Solder Seal.

f. Clean out the block via water down the top inlet and blowing compressed air back up through the blocks drain plug. You'll be suprised as to what amount of rust will come out.

Keep in touch and let us know how the above checks work for you.

Good luck,
Charlie

BTW: The problem is not in your overflow reservoir.

If the car has the original type lower hose it can not collapse as it consists of two short pieces of rubber hose with a metal elbow in between.
I would not run a 180 thermostat in a 1934, a 160 is just fine.
I wouls suspect the radiator core is plugged with rust.
Is the baffle in the block behind the water pump?

Thank you ALL for you comprehensive reply's.

Firstly I removed the thermostat earlier in the year for testing in boiling water and it opened and shut.
I did not replace it because I live in a tropical zone and consider that it is not really needed!
2 months ago I used a hight quality radiator cleaner that had to be run in the engine for 30 mins and then drained. The water was clear an clean.
I am now leaning to the fact that the core is blocked with 18 years of corrosion, despite it being a new install.
I noticed that the water does move across the top of the rad, so conclude that the pump vanes are indeed working and moving water.

Is there a way of removing the radiator without dismantling the front of the car, such as headlights, both front guard attachments, and many other nuts and bolts that hold the grill cowl to the rad?

I think that I will have to bite the bullet and go for gold, undo everything and extract the radiator and have it rodded?

thank you ALL for your ideas and support

Peter

.

****I did not replace it because I live in a tropical zone and consider that it is not really needed!****

thank you ALL for your ideas and support

Peter
[/quote]
===========================================================

You need to run a thermostat in your car.....160. You need to understand what the thermostat is in there for and how it functions within your cooling system.

Not running a thermostat is just plain dumb.!

mike

I agree a thermostat is a good idea, but not sure if they were standard original equipment. I am of the opinion that without it the temp should be cooler and that's what I experienced when I did not have one in my 32. The thermostats purpose is to maintain a constant and optimal heat range that promotes the best efficiency from the engine.

My all original 1932 Special Sedan came from the factory without a thermostat and after 80 years with the original radiator the car runs very cool in the summer. Most of the time the temp. gauge will not even get up to "Normal".

If the water in the system is allowed to just keep circulating and never allowed to be cooled down, then the motor will overheat if insufficient air is not passing thru the radiator as the water is moving down from top to bottom.

The thermostat keeps the water in the motor until it has reached the specified temperature of the thermostat (160 ?) and at which point it opens allowing the heated water ( 160 ) to move to the radiator. When the water temperature in the motor is sensed by the thermostat to be less than the 160 the thermostat closes keeping the water inside the motor until it again reaches 160 degress.

In the meantime the radiator takes the 160 degree water and with airflow and the fan removes about 30 dregrees temperature from the water as it moves down the radiator, and gets ready to re-enter the motor, where the cycle is repeated.

IF the thermostat is not present in the system, there is nothing to stop the constant flow of the water around and around , it never properly get cooled and eventually comes to a boil at 212 degrees. From there the temperature just keeps rising.

A pressurised system with a radiator cap will raise the boiling point of water by 3 degrees for every pound of pressure. 12 pound cap X 3 degrees = 36 degrees + 212 water boiling point = 248.

This is why thermostats and pressurised systems were brought into use back in the day and are still used today because the no thermostat, no pressurised system is/was not a good system. The guy with the properly functioning cooling system, is never the guy on the side of the road on the old car tour, in 95 degrees outside heat.

mike

The early six-cylinder cars did not come with a thermostat as standard equipment from the factory. A thermostat could be ordered for cars in cold climates. Another type of thermostat was available if an accessory heater was installed. According to the parts book, the thermostat was 145 degrees.

One thing to keep in mind that on the early six-cylinder engines there were no water jackets in the engine block so many of the earlier six-cylinder cars tended to heat up over the years, therefore a thermostat may or may not solve your heating issue. I know on my '32 it runs cold so there is absolutely no need to run a thermostat to make the car run hotter....and possibly cause an overheating problem. However, having said that, on some early Chevrolets installing a thermostat has actually made them run cooler.

Hi there Jerry,
I like that idea of the 1/8th hole and will try it if I install a thermostat....I have never heard of that before, and it has a smell of rocket science to it.

To me, a simple country boy,
thermostats are to control the water temperature when starting the vehicle from cold.

It holds the water system in a closed state until a predetermined temperature releases the flow of the coolant into the system, to then flow and conduct heat away from the water jacket and radiator. Thats is purpose...

By not having a thermostat, the water just flows as normal, rising with the heat generated and falling down through the radiator, being cooled by airflow through the radiator and back into the engine. Thats the end of the process...

If the downward flow is not constant ( blocked tubes) the water will stall and overheat, thus causing my problems (just a guess).
Time will tell what it is, I will keep you posted.

Peter

Your explanation is spot on!

As long as the laws of thermodynamics are not repealed the heat transfer process will be as described. Heat transfer is when heat is transferred from a hotter body (or surface) to cooler one. When dealing with liquids or gas (except for very high flow rates that are not within the capability of an auto water pump) the transfer rate is directly proportional to the heat differential and flow rate (volume and speed).

We be interesting to find what Peter discovers is the source of his overheating and what the fix is.

mike

Never had a cooling problem with my 32 without the thermostat and had it on several 6 cyl tours that averaged around 500 miles in 5 days. The gauge hardly moved off the cold reading and yes it is/was working correctly. I added a thermostat as with the original carb was only getting about 10 mpg and was hoping that would help-which it might have but not enough to be noticeable. I may be incorrect but I'm of the opinion the thermostat is fully open at its designed setting but the opening varies with the temp otherwise it would continualy open and close, thus some manufacturers refer to it as a "water regulator". I don't think the water pump capacity is sufficient enough to cause overheating due to high flow thru the radiator, at least it never did on my car. This system is fairly simple as it has coolant- a pump for circulation and a radiator for heat transfer. If the pump is working properly then blockage is the culprit. The next step is to determine where the blockage is-could be the radiator or the engine. Discussions of later systems will not help solve his problem, although interesting.

With everything being correct In most cases the water pump is capable of moving more coolant than most completely clean radiators are capable of flowing. The thermostat further restricts the flow up to predetermined temperature to provide quicker warm up and then is only there for the ride.
Tony

Thanks you Mike for your very comprehensive reply's, I do appreciate you input and advice as do many others in this forum.
I am at a quandary as who to follow and will try many ideas.

My main one now is to probably have the radiator cleaned in all respects and I will definitely let you all know via feedback what the solution is..........if I ever find one
(in the fullness of time Minister)

regards
Peter

Peter.........over heating and finding the cause is a multi step process of elimination as voiced by myself and others with possible solutions.

To get rad out you need to : remove hood assy, headlights & headlight bars as units, rad shell, rad support rod from firewall, top and bottom rad hoses.

Hardest part is getting the radiator side mounting 2 bolts out. Its not necessary to remove fenders or bumper.

You might also have to consider ***back flushing with water pressure *** the actual motor itself thru the thermostat or top outlet.

Your rad shop should be able to identify if your getting full flow without having to take top rad tank off . They will also advise you if your louvers/fins are making full contact with the tubes to remove the heat.

Its almost full summer time there now and nice time to be out putting around in car not thrashing away in hot summer temps.

Let us know what the fix is.

mike

howdy guys

one thing i didn't see mentioned here is that if your engine is out of time it will over heat.i had this problem when i first put my 1935 truck engine together and fired it up.
i have been running now with no thermostat all summer and truck
runs at about 140 degrees.all though i have read that 160 to 180
the engine smooths out and runs better,and i beleave this.
but if i had to guess, you are out of time and your exhaust valves are not letting all exhaust gases out. this will heat you right up.did you mess with the distributor lately???

jeff korner
southeast indiana

My 31 Chev was overheating and i tried everything. I finally got my own torque wrench and retightened the head. That did it. It runs cooler like it is supposed to. Just sayin'.....

Thanks, that sounds like a good place to start...!

Hi there Jeff

A neighbour mentioned the very same thing, if it is too far advanced it will over heat very quickly.
Before doing anything with the radiator I am going to check the timing. It has not been done in 16 years, since the engine was fully rebuilt and balanced.
I think that it can only be static timed from memory.
Using the aperture in the bell housing to display the pointer and the timing marks on the flywheel, and adjusting the distributor to just open the points, method. I dont think it has marks on the crankshaft pulley at the front for use with a timing light?
I will investigate further today.

Peter

hello again

on the ring gear fly wheel there should be a round ball beiring
looking mark that you line up with the pointer sticking out in
the hole in the bell houseing.
turn the engine over with the fan until the pointer points to the ball beiring ,then take the distributor cap off and see if your rotor is pointed at the number one fireing position.if not it's probably off another full turn,so make another full turn till ball shows up again.
i don't know if it is possible for the distributor or the timing chain to jump a gear and still even run but this may have happened maybe one or the other,just a thought.
i hope it's timing = easy fix.

jeff korner
southeast indiana

Peter
The timing is only done through the front of the bellhousing with the "ball" insert. The timing light will work on this set up and is much easier than a lot of alternative methods.

Tony

Hi peter,
Can't say I had overheating after 4 minutes but I had the same problem with over heating and blowing water out.
1. Had radiator back flushed by radiator specialist still had problem.
2.removed 180 deg thermostat and replaced with 160 deg may have helped.
3. Pulled out tap in back of block and shoved a piece of wire up the hole dislodged a heap of rust. Flushed block . May have helped.
4. The main problem I had was a leak in the rear welsh plug i believe this was allowing air to be sucked into the cooling system then blowing out the overflow. The leak seamed to get progressivaly worse over time, i think the coolant caused the acceleration of the corrosion. I used some leak sealer which stopped the leak and the car has run 10 deg cooler since . No more overheating and filling up after every run.
I think the160 deg thermostat helps as the 180 deg seemed to allow the motor to get to hot and then struggle to cool. Prior to my attempts motor used to run at about 190 deg and up to 212 deg, now sits on 180 or less.
Hope this helps. ( ps 1937 year model).