envoy_to_the_stars

31-57 Getting Hot

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Hello Everyone,

 

I just took delivery of Mark Shaw's old 1931 Buick 57.  It's in great overall shape, with just a few minor things that need to be looked at.  The most important of which (being that the car is now in Southern Texas) is the temperature.

 

When the car is sitting/idling, the temperature climbs slowly, and never really levels off.  This morning in 80 degree heat I watched it get up to 190 before I got nervous and pulled the plug.

 

It has the original honeycomb radiator.  The louvers on the front work properly.  Mark mentioned that has gotten hot in the past, and it may need a chemical de-scaling.  I'd like to try that first before I start getting more intense.  I've done this on other modern vehicles using a Prestone pre-mixed bottle that you let run through the coolant system for 30 minutes....I am happy to do that again on this vehicle, but I want to check and see if there are any intricacies I'm unaware of, or if there is a different method I should be using.

 

This is my first pre-war car, and I'm very excited to get started!  Thanks in advance for everyone's help.

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I have not found that  just running radiator flush through the system  on these early straight 8's solves overheating problems.  There are two problems that cover most of the overheating issues.  Radiator or sludge in  teh water jacket around the cylinders.  

 

My suggestion is start with the radiator.  drain the system.  remove the bottom radiator hose and plug the bottom radiator outlet with a ball or tapered plug.  fill the radiator with water, pull the plug and time how long it takes for the water to drain out.  Under 2 seconds is excellent.  Over 4 seconds means you have plugging problems in the radiator.  The honeycomb radiators have small openings and no straight path to the bottom.  Small particles that can't be dissolved end up preventing good flow through the radiator.  I removed my radiator, stood it upside down over a 5 gallon bucket.  I plumbed a hose from the bottom hose connection to an old hot tub pump.  I  rigged a suction line from the bucket to the pump. I filled the bucket with 4 gallons of 200 degree water and radiator flush.  I back flushed the radiator for 6 hours changing the water when it had cooled  room temperature.  When I was done I had found about a half cup of particles that looked almost like sand in the bucket.  I then did the drain down test and it would drain in less that 2 seconds.

 

On the engine water jacket, the cylinders are almost siamesed together.  Water from the pump enters the center and flows out the front of the cylinder head. This design does not get good flow the the # 8 cylinder.  I have worked on 7 cylinder blocks from 31,32,33 50 series cars.  Everyone of these engines had heavy sludge buildup in the back right corner.  To check this area, drain the cooling system, remove the rocker arm cover, remove the Passenger side rear head bolt.  This bolt hole is not blind and goes into the water jacket  The water jacket is about 3" deep.  A rod dropped into the head bolt hole should be able go in the head 8" and hit the metal water jacket floor.  I have found most of the engines I worked on to be plugged up to the bottom of the headbolt. With no water flow around the back 2 or 3 cylinders the engine overheats.  Remember, the temperature is read  off the back corner of the engine.  To clean this area is a pain.  I removed the oil temperature regulator in the center of the block and bent coat hanger wires to gouge back along the inner water jacket.  I also used a rod in the cylinder head bolt hole to break up the sludge. I flushed water down through the bolt hole to move the sludge up to the opening for the oil temp regulator.  

 

After these two processes, radiator and cylinder block I found the temperatures to run at 160 to 180.

 

The good news is that these processes can be done at low cost.  Don't let a modern radiator shop near your radiator.  They will apply too much pressure to the radiator and possibly damage the core.  A damaged core is a very expensive proposition.  There are people that claim there are certain chemicals that will break up the sludge.  I have not found them to work.  

 

I hope this helps you with your overheating problem.

 

Bob Engle

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I would also verify accuracy of the temperature gauge. It can easily be done with the infra red hand held guns. My 29 gauge shows about 15 degrees more than the actual coolant temperature.

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can u simply take the water jacket cover off the drivers side of the engine and the temp regulator off the passenger side and start flushing all the crud out and use a coat hanger and spray nozzle to clean it out good?

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The cylinders are so close that there is no good access to the passenger side of the water jacket. There is some room at the front and rear to snake a wire around #1 and #8 cylinders.  It is a good idea to check the cover plate as they are a rust problem.  While working on the water jacket, would be a good time to check the condition of this cover plate.  

 

Bob Engle

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I checked with my elderly father (it was his car) and he does not believe the cooling jacked was rodded-out when the engine was rebuilt.  However, this car was driven without overheating issues mostly in California where the summer temperatures are similar to Houston. 

 

Running slightly retarded will also cause overheating; so I would double check the timing first as it is much easier to advance the distributor.

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Hello everyone,

 

Just wanted to follow up here.  The timing and Air/Fuel mixture on the car have been adjusted to the exact specifications provided in the manual, and the temperature still climbs consistently past 180 and doesn't level off.  I cut it off at 195 to avoid damage. 

 

I did take a laser temperature gun on the radiator and found the 190+ degree temperature reading to be accurate.  I am going to try Bob's "upside down radiator fix" above next weekend, and see if that works. 

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When this car lived in central California, it had an overflow tank mounted on the firewall.  I believe it was in the trunk when it shipped to TX.

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When this car lived in central California, it had an overflow tank mounted on the firewall. I believe it was in the trunk when it shipped to TX.

Yep! I have it installed. The radiator isn't overflowing, it's just not flowing that well in general. Probably just some crud in there that needs to be washed out. I'm going to use this as an opportunity to re-pack the water pump as well.

Edited by envoy_to_the_stars (see edit history)

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My suggestion is start with the radiator.  drain the system.  remove the bottom radiator hose and plug the bottom radiator outlet with a ball or tapered plug.  fill the radiator with water, pull the plug and time how long it takes for the water to drain out.  Under 2 seconds is excellent.  Over 4 seconds means you have plugging problems in the radiator.  The honeycomb radiators have small openings and no straight path to the bottom.  Small particles that can't be dissolved end up preventing good flow through the radiator.  I removed my radiator, stood it upside down over a 5 gallon bucket.  I plumbed a hose from the bottom hose connection to an old hot tub pump.  I  rigged a suction line from the bucket to the pump. I filled the bucket with 4 gallons of 200 degree water and radiator flush.  I back flushed the radiator for 6 hours changing the water when it had cooled  room temperature.  When I was done I had found about a half cup of particles that looked almost like sand in the bucket.  I then did the drain down test and it would drain in less that 2 seconds.

 

Bob Engle

 

Bob,

 

I will be away from home this week, and won't have access to a pump to recirculate water in the manner you mentioned, but I will have a hose with a hot water tap!  Would it be worthwhile to turn the radiator upside down, stick a hose with hot water in the top, and flush fresh water through it overnight?  I could stop every once in a while to slosh some chemical cleaner through there...

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I had a '32 - 56 that ran hot when I bought it. In place flushing it didnt help. I removed the radiator, turned it upside down and flushed it that way. The amount of crud that came out was incredible. The car ran to cold after that until I got the radiator shutters working properly.

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I had a '32 - 56 that ran hot when I bought it. In place flushing it didnt help. I removed the radiator, turned it upside down and flushed it that way. The amount of crud that came out was incredible. The car ran to cold after that until I got the radiator shutters working properly.

 

That's promising.  I'll see if I can get the radiator out today.  I haven't looked at it too closely yet, but I imagine it involves removing the hood cowling and the radiator shroud, right?

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On 32 buicks, you need to remove the entire front grill assembly.  It's fairly easy as there are only 2 bolts on the bottom and the tie rod at the top.  Remove the hood assembly, disconnect the hoses, remove the tie rod, remove the bottom nuts (they are cotter keyed) and lift out the assembly. Keep track of the shims on the bottom as they locate the height of assembly for good hood aligmanent.

 

On back flushing, the key is lots of waterflow  to promote flushing across the entire width of the radiator.  A small amount of water will flow  just down the center.  Do the flow test first.  The entire radiator should drain in less than 2 seconds.  After back flushing, you can see if you have improved the flow.

 

Bob engle

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On 32 buicks, you need to remove the entire front grill assembly.  It's fairly easy as there are only 2 bolts on the bottom and the tie rod at the top.  Remove the hood assembly, disconnect the hoses, remove the tie rod, remove the bottom nuts (they are cotter keyed) and lift out the assembly. Keep track of the shims on the bottom as they locate the height of assembly for good hood aligmanent.

 

On back flushing, the key is lots of waterflow  to promote flushing across the entire width of the radiator.  A small amount of water will flow  just down the center.  Do the flow test first.  The entire radiator should drain in less than 2 seconds.  After back flushing, you can see if you have improved the flow.

 

Bob engle

 

 

I finally had time to get the radiator out today.  I'm going to start flushing it upside down tonight, and then run some hot water and CLR through it.  A few gallons of not-really-that-bad water came out of it when I drained it, and the engine was recently rebuilt so there shouldn't be much scale in the system from the block.  I'll report back shortly!

 

FYI - this video shows the process fairly well if anyone is bad at visualization:

 

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I dont get it it is a radiator you take it to a radiator shop and get it boiled.the risk of overheating is to great.

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I dont get it it is a radiator you take it to a radiator shop and get it boiled.the risk of overheating is to great.

 

Most radiator shops in town quoted me $750+ to get the radiator steam cleaned with a few weeks of lead time, due to the age and complications of working with honeycomb.  All of them were very clear that they couldn't guarantee they wouldn't break it in the process.  So I decided to pass on that unless absolutely necessary.

 

Before I ran any water through the radiator, I hosed it down with cleaner/degreaser and sprayed water through the honeycomb fins to clean it out.  A disgusting amount of bugs, dirt, rocks, and general dirt fell out of the fins.  A big portion of the area 3 inches on either side of the top inlet didn't even let pressurized water pas through from one side to the other.  Now, water flows easily from front to back, and after running water through the radiator upside down and letting hot water and CLR sit in it for a few minutes, the radiator empties in 4-5 seconds.  I'd call that "good!" 

 

I feel confident that the radiator is in good shape now - I'll re-install, add new coolant, and see how it does!

Edited by envoy_to_the_stars (see edit history)

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Gents, I have some [preliminary] good news!  After cleaning out the radiator and checking flow and filling up with 3 gallons of Peak Green Conventional coolant (mixed 50/50), the car maintains 160 degrees even when sitting still!  Before in a similar situation, it would reach 190 and keep climbing. 

 

It looks like spraying all of the crud out of the honeycomb made a huge difference in the ability of the radiator to transfer heat, and flushing upside down with CLR cleared out some sediment that may have been causing issues as well.

 

I say "preliminary" good news because it's rather chilly outside (60s) and I have not put the hood back on - so there is a bit more natural airflow over the engine right now than there wood be with the hood on, obviously, and it's about 45 degrees hotter outside in the summer than in the winter.  But I'm excited about what I'm seeing so far! 

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Another update:

 

Today was about 70 degrees and sunny outside.  I put the hood back on Betty and took her out.  She maintained 175 degrees without issue with the hood latched - both idling and driving.  It appeared as though the louvers didn't need to open all the way to maintain that temperature, so we may still have a ways to go (which will be helpful in the summer). 

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