VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1933-1936 33 Master running hot

My 33 Master that has not been driven much in the last 20 years is running hot. I plan to start using the car quite a bit. I flushed it and it was only slightly dirty. It is still running at 180 degrees with the thermostat removed. When I am traveling slow it gets close to the boiling point. I felt the radiator and it gets hot at the top and only warm at the bottom. I assume that this means that it is plugged.

I had it off last fall and was not aware of a problem but I still had it tested at a radiator shop. I had it off because I repainted the car.

Any suggestions on a fix without removing the radiator or any other suggestions would be appreciated.

Are you sure the temp gauge is reading correctly?

There should be a difference in radiator temp between top and bottom or the radiator isnt doing its job, a large difference may be a indication of partial blockage.
Tony

The purpose of a thermostat is too control the temperature all the time. The thermostat keeps the water in the block until the set temperature is reached then it allows the water to exit to the radiator, where the radiator function removes about 30 degrees of temperature. The water/antifreeze mix in the block then reaches the 160 or 180, thermostat opens again and the process continues.

If you remove the thermostat the water is continuously flowing , heating up and never getting a chance too cool the way the thermostat controled system is designed to work.

With the simple 4 blade fans on these motors, they just do not draw enough air thru the radiator to assist in the cooling.

Try running a 160 degreee unit. Also make sure your rad cap is sealing properly.

The biggest mistake people make is to take the thermostat out when the problem most likely lies elsewhere in the system.

mike lynch

Thanks for the help.
It was running hot and I had just put a new thermostat in it. This car had not been run much in many years. I removed the thermostat and flushed it out. The system was not very dirty. I put a 50/50 mix of Antifreeze in it.

The temp gauge moves as if it is working. It goes back to 0 when it cools down. What is the best way to test a temperature gauge, without removing it from the car?

If your temperature gauge is a mechanical unit....has a probe temp sender that fits into motor, runs thru a copper line to the temp gauge, you have a mechanical unit. You can remove the probe/temp sender and place it into a sauce pan with boiling hot water.....that will tell you right away if your gauge is correct if its showing 210--212 degrees. Without removing it from the car.

But you say your gauge goes back to 0, i would have to say its working. Make sure you have your system full to bottom of radiator fill and watch the water flow inside for bubbles. Keep vehicle running for a while and adding any more water needed until your sure you do not have an air pocket in the system. If you have a shutoff valve in your heater hose, open it fully to increase the flow of coolant.

Bubbles is not a good sign, can indicate cylinder head gasket leak. If you have them and they will not stop, you have a problem.

You can take a CLICKER TYPE torque wrench ( borrow one if you have too ) and using the ****correct torque settings**** and in the CORRECT TORQUE SEQUENCE , go over each cylinder head bolt until the snap sound is heard from the wrench. Do not under any circumstances grab an 15-18" socket bar and put a socket on it and start reefing on the head bolts !!!!!!! you will over stretch the head bolts and maybe break one. Over stretched head bolts are junk and should be discarded.

Another thing that can reduce the effectiveness of your cooling system is the radiator core. The fins must be tight against the tubes in order to extract the heat.

mike lynch

I meant to say that you bring a pot of boiling hot water to the temperature probe and insert it in the water to watch the temps rise in the hot and fall as it cools.

doesn't get any simpler than that , other than using a lighter to heat it up.

mike

You could also have air entering thru the packing on the water pump. An inexpensive heat gun (harbor frt.) can help to pinpoint hot spots and check the temp difference of the top and bottom of the radiator and also to check your gauge accuracy.

I wonder if a shroud would help the fan??? I would rather have a cool motor with a homemade shroud than no shroud and no motor.
And how 'bout our pretty radiator caps? Do they effectively hold pressure? These are the things I lay in bed and think about. :)

I do not think the stock rad cap / ornament is a pressured item. You would have to take the radiator out, have the top fill sealed and then have a pressurized 90 degree metal part and for a hnew style rad cap system.

Note...these stock radiators were not designed to be pressurised much. I would not exceed a 5 pound cap, which will raise your boiling point by 3 degrees per pound of pressure , so thats 212 + 15 = 227 degrees.

If your going to fabricate a schroud, look at the newer factory stuff or spend an afternoon at the scrap yard and see what you can come up with. you might want to check with the street rod radiator makers to see what they offer for your particular vehicle.

When i had that 33 master motor that came in my 35 , i was looking at the fan with an idea of using a 6 blade steel fan from vintage air in texas. I cannot remember what i figured out , whether it would be adaptable or not to the stock water pump ???? I will say that i used the 6 blade steel fan on another car and i cured a temp problem on the car. The fan really draws a high volume of air thru the rad. It will drag a cloth diaper at idle too the radiator from 9-12" away and hold it there.

The 6 blade steel fan is not to be confused with the aluminum fans sold by the performance shops. Just place them in the trash, they are useless except for drag racing.

mike lynch.......

The cause of the overheating, which is usually restricted flow through the core, should be corrected rather than covering it up with things like a pressure cap to raise the boilmg point a few degrees..

I also agree.

Just a though. You said that the car has been sitting for some period of time.If you havent changed the fan belt it might be a good thing to do just as a maint item.If you have access to a strobe light (one that you can set the speed)usually used in vibration diagnostics. You can check to see if the belt is slipping.I had my radiator recored as I had a very simmilar situation. My rad looked to be in good condition but it was 60%plugged. Made all the difference in the way the car ran.

In the first post in this thread , on the 20 year sitting car, the owner chevy cop, said he had the radiator checked last year.

So what your saying is he should pull the rad again and have it flow tested. I think thats the first thing one should do. But he does not want to.

mike

Is it a big job to remove the radiator? Does the whole grill assembly have to come apart?

Mike,

"If you remove the thermostat the water is continuously flowing , heating up and never getting a chance too cool the way the thermostat controled system is designed to work."

I think that removing the thermostat generally makes the system run too cool rather than too hot. So, I'm not too sure about that statement. With respect, you may want to think about it some more.

Charlie

My book suggests a reverse flush is the best way to flush the system. It might be something to look into before pulling the radiator. Some of the local old timers run the engine to 190 then add a diluted cup of baking soda for 5 minutes. Shut it down and flush two times. I never tried it. I would like other thoughts on this one!

Charlie......your 100% correct, i stated the wrong info. I telephoned the smartest auto guy i know for last 40 years and he verified exactly what you said. He said running too cool is not good as the gasoline needs the heat for the fuel to atomise properly for combustion and fuel economy. Better the car is running 180--190 temps. He said the new cars generally run at 210 and up for fuel atomisation and economy.

mike lynch

I appreciate all of the input on this subject. I have gone over everything on this car mechanically. It has a new top (it is a cabriolet) and Hampton Coach interior, that I bought 20 years ago. It was taken apart and given a new paint job. Since it has not boiled, I think I will drive it on short trips for a while before doing anything with the cooling system.

I plan to take it to the Central Meet in Port Huron MI.

Increased usage should help to determine if you do indeed have a problem. Checking the accuracy of your gauge would be a good first step. Why wait until it boils over to confirm that its accurate?

After setting 20 years I would suspect the block and head are full of rust.This rust is finding its way into the rediator core. You are going to have to bite the bullet and do the following. Remove the head and block freeze plugs and water pump. Poke and probe with coat hanger wire in all the open holes you can find. Flush and try to use some pressure. Same for the head.
remove the radiator and have boiled or rodded out. This will need to be done sooner or later and sooner is better before you end up cracking the head.

The car did not sit for 20 years but it was driven infrequently during that time. It was driven at least once every summer. The motor was completely rebuilt and balanced prior to the 20 years of infrequent usage and only has about 1000 miles on it. It was kept in running condition during that time. When I flushed the system there was no rust in it.

The radiator shop, which is run by an old timer, said that the radiator tested good. He advised me to leave it alone since this type of core is not repairable.

Running hot? Tell me about what was done with the balancing of the engine.

When I bought the car the motor was done. I have had it for about 25 years and it runs great. I have put around 1000 miles on it since I have owned it never ran hot until recently. I have discovered my problem it was something that Jack Kennedy hit on. The fan belt was slipping. Something that I should have discovered sooner.

It happened because I am getting the car ready to be judged and I took off the modern belt that I had on it and put on an original equipment type belt. I will be ordering a new belt along with some other items, from the FS.

It just goes to show, always check the basics first.