Buick `41 running hot.

[falco]

Hi, my `41 46S with dual carbs is still running hot after a Hyway drive from about 50 mls at 55 mph. This at a outside temp from 71 degrees, water temp rises to 215 degrees. It only happens at hyway use. I think I have everything done to make it alright. A new block in the radiator, rebuild the waterpump, cleaned the cylinder head and engine block, adjust the ignition, installed a colder thermostat, and make closer the valve under the thermostat to have a less mixture from hot and cold water. Also I`ve checked the temp gauge and installed a electric fan in front of the radiator. I put also 2 new edelbrock 94 carbs on the car and make them simultaneously, it runs great and save`s fuel. Last week I put the car on the dyno for fine tuning and it has 94 Hp on the rear wheel, not bad I think. Has anyone a suggestion for my temp problem? Thanks, Bert (Netherlands)

[Guest Grant Magrath]

Hi Bert.

Did you put a new core on the radiator before you did everything else? Your radiator may have become blocked again after all the junk was loosened from the engine.

Cheers

Grant

[Mark Shaw]

The bottom radiator hose can become soft over time and collapse under load.

If you can squeeze it together with your fingers, it needs to be replaced.

[g-g-g0]

Bert:

Sorry to hear that you are still experiencing problems with your car. How about posting some pictures of your car now that it is road worthy? I hope to have my '42 running in time for the show in South Bend in July. It is as the pictures you last saw of it except it now has brakes, getting the fuel system cleaned out and hopefully running by July.

Hope you find a simple solution to your over heating issue.

Gary

[falco]

Thanks for your reactions. I`ve cleaned the engine during overhauling and rebuilding last year. After that I cleaned the radiator ans engine several times, but no result. I`ll check the lower radiator hose but it`s one year old. I can drive the hole day with 45mph with no problem but 55 - 60 mph on the hyway give problems. is it possible that the vacuum advance gives the problem? I`ve 32 degrees advance at 3000 rpm. Thanks, Bert

[Vila]

I am not a Buick guy, but there is one the list of cars I would like to own.

Yes it could be any of the issues mentioned above or several other things including the oil you are using.

Your rebuilt engine may have a lot more internal friction until it gets fully broke in and the increased friction may have increased the operating temperature beyond what the cooling system can handle.

I had a similar issue with the 1933 Chevrolet I have owned for 42 years, and the engine had been rebuilt just prior to me buying it. No matter what I did, it always ran hot until I change from (and I hate this term) "Old School" oil to Valvoline VR1 Synthetic Racing oil back around 6 years ago. I have never driven the car more than around 100 miles per year because of the over heating issue. In fact from 1972 to around 1992 I drove it a total of around 250 miles. This Valvoline oil has a high ZDDP level for older flat valve lifters and must be slicker than H, and "I believe" the reduced friction in the engine is what eliminated my over heating issue.

Visit my website at: http://mysite.verizon.net/vze114b79/id1.html

Vila

1933 Chevrolet Master 5 Window Coupe

1962 Triumph TR4

1984 BMW 633 CSi

[superbuick]

You have the classic signs of a poor radiator. With age it get clogged in several places. After that the efficiency goes down. You can drive an old car with 40-60% efficiency at low speeds, but when driving at highway speeds, or a longer grade it will heat up rather quickly. Then should go down just as fast when slowing or going down hill.

You can check the temp of the radiator when is hot with a temp gun. It should be the same temp all the way across. You will find plugged spots were there are low temp areas. Good money spent to have it boiled out and re-cored ass necessary. Your ignition timing sounds OK to me.

Good luck, Steve

[Guest Grant Magrath]

Vila makes a good point. The internal friction on a newly rebuilt engine makes for hotter running at first. I replaced the engine on my daily driver, and it runs hotter than the old one over hills. So as an experiment, I flushed the radiator and put an additive in the oil. And it worked. Ran a lot cooler. And Mark is right about the lower hose. They have a spring in them to prevent collapsing, and they can rot away. Either way, you have plenty of ideas to work with!

Cheers

Grant

[danhar1960]

Interesting to hear about different oils.

These problems most times come back to a partially blocked radiator.

When you say "a new block in the radiator", do you mean you had a new core fitted ??

Danny

[Brian_Heil]

At highway speeds, you have more than enough (ram) air flow, unless one or both of your fans is backwards (hey it happens, is the puller pulling and the pusher pushing?)

How did the vanes on the water pump impeller look? All there? In the correct direction and not backwards? And the belt is tight?

Agree, about the classic signs of plugged core. Heat rejected to the coolant is proportional to the brake HP. At higher speeds, it takes more HP and you reject more heat. The cooling system can handle the heat rejection rate at 45 MPH (ie you have enough air flow, coolant flow and radiator dissipation capacity). Assuming good air and water flow at 55 then things point to the radiator not keeping up.

Cars that won't cool in parades or at idle often suffer from a lack of air flow, you are not putting out any coolant flow to speak of so even your tired and plugged radiator can keep up with the low coolant flow and low heat dissipation load at idle but that half dead radiator needs more air flow to work so they add a pusher fan to cover up the radiator and solve the idle problem.

The missing wire in the suction hose is a good one.

You can do a 'poor man's flow check'. Remove both radiator hoses and stick a garden hose (full on) in the radiator, it should easily handle this amount of flow without burping back or building any pressure as you seal the garden hose at the top of radiator with your hand.

The problem with plugged core paths is they stay plugged even as you try to flush things out.

OK, 'war story' time. Engine would not cool, would only run a few minutes. Guy tried everything, even bought a new radiator. Engine even went back to re-builder where it again ran and cooled fine on their stand because they thought they had a 'friction issue'. I got a call, to please come look because he was ready to sell the car and his wife was ready to divorce him from all the stress. Car did overheat but the radiator was not that hot. Hmmm no flow, boiling the coolant in the engine only. Poking around, I found a plastic shipping plug from the re-builder stuffed in the water pump inlet, Re-builder put it there each time he had the engine done and on the pallet to keep the engine from dripping in his spotless shop. After I fixed his car I heard the guy continued to overheat and she left him.

The other odd-ball I once found was an impeller that was perfect but was no longer attached to the shaft, the drive pin had sheared. Shaft and fan spun like hell, the perfect impeller just stayed put inside the pump. Pulling off the upper hose while running (and no flow) helped me find that one. Pump looked perfect on the bench. Always check to see if the impeller is attached to the shaft soundly, press fit, pin, whatever.

You may laugh, but the toe of a panty hose over the engine out hose going to the radiator will catch all sort of stuff. Clamp it in there and leave it there for a hundred miles. Good trick to do on any old car you buy and cheap too. So is a garden hose back flush of the radiator. Buicks had a reputation for excellent cooling systems. If your car does not cool, there is something wrong, it's not due to a poor design or weak system.

[Guest Grant Magrath]

Great post Brian! Bought my wife an old BMW that had overheating issues, but they're well documented. Plastic water pump impellors get old and shed vanes, leading to overheating and blockages. New ones are metal and are good. Maybe Franklin cars were onto something back in the day? (air cooled)

Cheers

Grant

[falco]

Hey guys, thanks for all information. Yes with "block" I mean the core. Also I`ve put the garden hose in the radiator, it comes out just so fast as it commes in. The spring in the lower hose is a good one. I will check the water pump again on the flow. The both fan blades turned in the right direction. Now I think, maybe the flow is to low. Thanks, Bert

[falco]

Hi Gary, Good to hear from you here. I`ve a picture in my photo gallery. In february I bought also a `42 Buick Century 4 drs in New Mexico, sadly the car is still in the States. On the last moment it seems there is no Title with the car. Lucky me, I don`t have paid for the car jet. The Motor Vehicle Division is investgate now foe 3 month. Succes with your car, and let me know. Bert

[danhar1960]

Could it be that the new carbs are jetted to small and it is running lean??

You say "I've 32 degrees advance at 3000 rpm"

Going by the book, full advance should be 13@1500 rpm. Did you check the springs in the centrifugal advance ??

Danny

[Aaron65]

Could it be that the new carbs are jetted to small and it is running lean??

You say "I've 32 degrees advance at 3000 rpm"

Going by the book, full advance should be 13@1500 rpm. Did you check the springs in the centrifugal advance ??

Danny

13 degrees distributor advance at 1500 RPM means 26 degrees crankshaft advance at 3000 RPM. Therefore, if you have 4 degrees initial, your total advance is 30 degrees at 3000 RPM. Then you must add your vacuum advance at cruise. Bert, I assume you checked the vacuum advance...??? If that's not working, you'll run a little warm. Additionally, did the dyno operators check the air-fuel ratio when they were tuning the car? I would think the carbs would have to be lean enough to cause driveability issues if they were lean enough to cause higher engine temps. Did '41s have a pressurized cooling system?