1925 Chrysler four cooling

[marbeton]

My 1925 Chrysler four keeps the engine warming up a lot. I replaced the seal under my head, I had the radiator cleaned in a specialist workshop, but the temperature is still just below 100 ° C. The water pump does not have this type. I don't know what else to do and where the problem might be, so it occurred to me that I could replace a two-blade fan with a four-blade fan from a six-cylinder B-70. Not sure if that would be possible? My fan has a diameter of 17 ". Thanks for advice.

[viv w]

Hi Marbeton,

 I had a Model 52 for years and did some long trips of over 450km in a day, with summer temperatures in the mid 30c. The car ran pretty hot most of the time and at night the exhaust pipe from the manifold would glow red hot . At times it would occasionally boil and spit a bit of coolant from the radiator cap, so at least I knew it still had water, but it ran happily and never let me down from overheating.

 That was over 20 years ago and I have learned a lot since then.

 Check your spark plugs to make sure they are the right heat range, plugs of the wrong type can cause overheating.

 Check for cracked manifolds or faulty inlet or exhaust manifold gaskets, if they are sucking air, it will run hot.

 Try retarding the ignition a bit, you may have advanced the timing too much causing it to run hot.

 What carburettor are you using? maybe your jet sizes are too small causing it to run lean and hot. I ran my model 52 with a model A Ford carburettor, you could adjust the mixture from inside the car depending on your driving conditions.

 The last thing I recently read about is the octane fuel you are using, and I believe this may be why my cars exhaust got red hot. The old cars had low compression engines, that during their heyday used fuel with probably an octane rating of about 65. Todays modern fuel has octane ratings of 85 (regular) and 93 or 95 for super grades. They say the low compression motor, when using high octane fuel, does not burn all the fuel inside the combustion chamber and when the exhaust valve opens the still burning fuel gets pushed out the motor into the manifold. This can cause a motor to run hot and may explain why my manifold got red hot. They say use as low an octane fuel as you can buy and even suggest lowering the octane by adding some paraffin up to 20 percent. I have not tried this out, so I'm only telling you what I have read. Perhaps google this subject , I came across it when researching problems with ethanol/ alcohol fuels .

Regards

Viv

 

[marbeton]

Hi Viv,

thank you for your experience. I have new spark plugs type AC 78S. You should be right for my type.

The manifold cover is new, as is the exhaust and intake manifold seals. But the fact is that the intake manifold that is bolted to the exhaust is always very hot. I put a heat-resistant pad between the intake and exhaust pipes (some were there, but they didn't last). So maybe the problem could be here too.

I adjusted the ignition advance by listening, because I now use petrol with an octane number of 95 (in our country it has the lowest octane number and I have to add a special lead supplement, because the current petrol is unleaded) and then it was in Year 1925 about 65. Therefore the advance value given by the manufacturer must be today's petrol smaller. So a smaller lead value.

I have an original Stewart carburetor. There could probably be a problem as well. Unfortunately, I don't have any documents from him, so I don't really know how to properly disasemble and set it up. So far, I've only cleaned it and fixed the needle at the very bottom. I also adjusted the saturation of the mixture just by listening so that the engine ran smoothly and at the lowest possible speed.

I know that there shouldn't be a problem with the original radiator propeller, if the manufacturer supplied it that way, and that the problem will be somewhere else. That propeller replacement was my last idea of what to do. But I'll try some of your advice.

I hope I wrote it correctly in English🤨

Thanks

marbeton

 

 

[28 Chrysler]

You can lower the octane by adding 5 -10% fuel oil (diesel fuel). Also lead will raise the octane a bit, that was an octane boaster in the late 1920s.

[marbeton]

I'm still thinking about how to prevent it from overheating. Now I had another option. There must be a seal between the intake and exhaust manifold. There is an opening in the exhaust manifold where the exhaust gases go directly to the intake manifold and thus also heat the petrol mixture into the engine. Should there be a seal to prevent that direct heating, ie full, or has the manufacturer already anticipated this, and should there be a seal only around the perimeter? When I disassembled the engine, there were only some rests of the seal, from which it was impossible to tell what it originally looked like. So I put the seal there only around the perimeter. The photos show the exhaust manifold with the hole and also two variants of the seal, which I made. Don't know what's right? And how do you have it with your cars, for example.

Thanks

marbeton

[hchris]

Given that you don't have a water pump, cooling will always be marginal on a thermo syphon system. 

 

The fact that you've done the radiator would probably suggest that the block might need a good flush out, after all the cooling effectiveness is very much dependent on good circulation, do you know what condition the block is in ?

 

A bit of online research will give you various product options for a flush out, you might want to be a bit creative with the flushing by disconnecting the radiator, be a shame to fill it up with crud.

 

Also invest in one of the hand held infrared thermometers and move it over various parts of the engine looking for hot spots, the back of the block for instance.

 

While your at it you can check the effectiveness of the radiator by noting the temperature difference between the inlet and outlet ports of the radiator, ideally there should be around 25 degrees drop between the two, if that's the case then the radiator is doing it's job. 

[Max4Me]

Marbeton,

I have a 1925 Maxwell/Chrysler Four (made in Canada before Chrysler completely took over. The firewall plate does say "Maxwell/Chrysler." Nevertheless. I'm betting my car is basically the same as yours. I live in the foothills of Southern California mountains and our temps range from 17-20 degree F. (about 6-7 degrees C, I think) winters to more than 110 degrees F. (40-41 degrees C, I think)in summer. I have a 17" two-blade fan. (Though I'm confused about your statement The water pump does not have this type.) Mine does not have a water pump, it is convection type.) Even in the heat of summer on a stop and go drive around the neighborhood the mercury thermometer never goes up higher than 2/3 of the way, so I'm guessing the fan blade is not the issue. I will take it out tomorrow and check with a digital thermometer and give you an exact temp reading.

 

I can't add much to what's been said except that I agree it could be timing and/or lead. From what I've researched fuels in the '20s did not have lead in them. Also, because fuels of the  day probably were not manufactured as carefully as today, some people did put in lead additives to raise the octane level to stop pinging. I have not had the manifolds off so I can't speak to the issue of seals. Best wishes on your issue.

 

 

 

[marbeton]

Thanks for the help. I renovated the car to the condition it left the factory in 1925. So it does not have a water pump and the fan is also the original two blades. As you write, the engine must cool down even in high temperatures, as you write that it is at home with you. So it should work for me too, where temperatures are at most 30 ° C. Unfortunately, there is a mistake somewhere and I am still looking for where. The radiator is cleaned, the seal under the head is new, and when it was replaced, I also cleaned the inner primers of the head and engine block, where there is coolant. The radiator hoses are new. Now I will try to see if the overheating of the heat seal between the intake and exhaust manifold does not affect this. I don't know what to look like yet. I have two options (photos are also here). The spark plugs are new (they have driven only 8000 miles) and are AC78S, so correct. I'll try to find out the temperature differences at the top and bottom of the cooler, as "hchris" advised me. Then I don't know what to do next.

Can you please send me some photos of your car? Especially what the engine, floor and curtains look like. If you have them original, it would be a good inspiration for me. In all period photographs, the car is only from the outside, but nowhere is what the floor looked like. And if there are curtains, it is not proper to know how they are attached and how they originally looked. I am also sending you a link to photos of my car, which is listed in the catalog of world cars, which is made by one person in our country.

https://auta5p.eu/lang/en/katalog/auto.php?idf=Chrysler-Four-Touring-22322

If you wanted to bring your car there too, it could be arranged.

marbeton

 

 

 

 

 

 

 

 

[viv w]

Hi Marbeton,

 First thing, the picture of your exhaust manifold shows what looks like a hair line crack on the left side of the opening, this crack needs to be welded or the manifold replaced.

 Secondly, the gasket that goes between your exhaust and inlet manifolds, I seem to recall it just went around the edge of that hole.

 When replacing the above gasket, it is critical that the correct thickness of material is used, and once you have replaced that gasket make absolutely sure that all the exhaust and inlet ports are an even height before bolting it up to the block. Failure to do this will result in either cracking one or both manifolds or sucking air into the block. If you are not sure, then bolt the 2 manifolds together with a new gasket and ask a competent machine shop to make sure they are level, they may have to grind them, the same way they would skim a head or block.

Viv.

[Max4Me]

Hello, Marbeton,

Here's some followup information for you. I took the car for about a 15-20 minute drive (83 degree F air temp, 23 C) and then checked the water temperature. I used a digital probe thermometer and an infrared thermometer. They read slightly off from each other but not significantly (just a degree or two Fahrenheit), so I'm giving you the average of the two. At the fill opening with cap off, the temp of the water is 183 degrees F (84 C). On the outside of the upper return fitting on the radiator inside the engine compartment the temp is 171 degrees F (77 C). Interesting that there would be such a difference. I did not check the temp at the fitting at the bottom of the radiator, but will be glad to if this helps. One interesting thing that I never noticed is that the fan blows air forward through the radiator and not back toward the engine. Not sure what to think of that. I may try reversing the fan blade and see what happens. I have Champion W 14 spark plugs which are exact replacements for the AC 78s plugs you have so I don't believe that's an issue. I have a Zenith carburetor on mine. In one of the manuals I have (darn if I can locate the info right now) it lists the carburetors on the 1925 Four as Ball and Ball, Stromberg and Zenith. Though interestingly enough, the owner's manual illustrates and gives adjustment info on a Stewart, even though it does not specifically name it.  Go figure.

 

Beautiful car you have. Mine is not nearly as finished so I doubt I can send pix that would be of any help to you. I 'rescued' it from a gentlemen whose grandchildren wanted to chop it into a street rod. It's a popular thing here in Southern California (and maybe else where) because the pollution controls required are based on the VIN/serial number of the car, NOT the engine. Hence people put a heavily modified big block engine in old cars and don't have to meet any smog requirements.

 

VIV has much more experience than I so that is a voice to which I would pay heed. Best wishes and good luck with your troubleshooting.

Marbeton, 

 

P.S., in my original post I stated I'd read people in that era put lead additives in their cars to prevent pinging. It is true that I read that at least twice, and having not lived in the 20's, I can't personally swear to this. However, in retrospect, l even with 60-70 octane rating back then, I can't believe an engine with such low compression would have trouble with pinging. But again, I wasn't there.😬

[28 Chrysler]

On a engine with a 6 to 1 compression ratio the octane rating should be around 60,  10 to 1 around 100 octane, this is all in general.

As for turning your fan over all you are doing is changing the leading edge not the flow.

[hchris]

6 hours ago, Max4Me said:

Hello, Marbeton,

Here's some followup information for you. I took the car for about a 15-20 minute drive (83 degree F air temp, 23 C) and then checked the water temperature. I used a digital probe thermometer and an infrared thermometer. They read slightly off from each other but not significantly (just a degree or two Fahrenheit), so I'm giving you the average of the two. At the fill opening with cap off, the temp of the water is 183 degrees F (84 C). On the outside of the upper return fitting on the radiator inside the engine compartment the temp is 171 degrees F (77 C). Interesting that there would be such a difference. I did not check the temp at the fitting at the bottom of the radiator, but will be glad to if this helps. One interesting thing that I never noticed is that the fan blows air forward through the radiator and not back toward the engine. Not sure what to think of that. I may try reversing the fan blade and see what happens. I have Champion W 14 spark plugs which are exact replacements for the AC 78s plugs you have so I don't believe that's an issue. I have a Zenith carburetor on mine. In one of the manuals I have (darn if I can locate the info right now) it lists the carburetors on the 1925 Four as Ball and Ball, Stromberg and Zenith. Though interestingly enough, the owner's manual illustrates and gives adjustment info on a Stewart, even though it does not specifically name it.  Go figure.

 

Beautiful car you have. Mine is not nearly as finished so I doubt I can send pix that would be of any help to you. I 'rescued' it from a gentlemen whose grandchildren wanted to chop it into a street rod. It's a popular thing here in Southern California (and maybe else where) because the pollution controls required are based on the VIN/serial number of the car, NOT the engine. Hence people put a heavily modified big block engine in old cars and don't have to meet any smog requirements.

 

VIV has much more experience than I so that is a voice to which I would pay heed. Best wishes and good luck with your troubleshooting.

Marbeton, 

 

P.S., in my original post I stated I'd read people in that era put lead additives in their cars to prevent pinging. It is true that I read that at least twice, and having not lived in the 20's, I can't personally swear to this. However, in retrospect, l even with 60-70 octane rating back then, I can't believe an engine with such low compression would have trouble with pinging. But again, I wasn't there.😬

 

Yep, definitely need to turn the fan around.

 

In reality once your moving, most of the cooling will be from road draught, the fan comes into play at slow speeds and when stationery. 

 

Pretty sure that octane ratings aren't in play here, as mentioned compression ratio is well below the threshold and whilst the cracked manifold definitely needs fixing i doubt it would be affecting the radiator temp.

 

If the engine was rebuilt is it possible the timing is out ?

[marbeton]

9 hours ago, viv w said:

Hi Marbeton,

 First thing, the picture of your exhaust manifold shows what looks like a hair line crack on the left side of the opening, this crack needs to be welded or the manifold replaced.

 Secondly, the gasket that goes between your exhaust and inlet manifolds, I seem to recall it just went around the edge of that hole.

 When replacing the above gasket, it is critical that the correct thickness of material is used, and once you have replaced that gasket make absolutely sure that all the exhaust and inlet ports are an even height before bolting it up to the block. Failure to do this will result in either cracking one or both manifolds or sucking air into the block. If you are not sure, then bolt the 2 manifolds together with a new gasket and ask a competent machine shop to make sure they are level, they may have to grind them, the same way they would skim a head or block.

Viv.

Hi Viv,

the exhaust manifold in the picture is old, which I had to replace with another one. So that I don't have to disassemble the new one from the engine, I took a picture of the old one for illustration. When I put it together, I leveled the seal so that the exhaust and intake manifolds were level. So in your opinion, the seal between the intake and exhaust manifolds should only be along the edge, and so the exhaust gases preheat the gasoline mixture in the intake manifold. That's how I did it. So there probably won't be a problem here. I have to keep looking.

Thanks

marbeton

[marbeton]

8 hours ago, Max4Me said:

Hello, Marbeton,

Here's some followup information for you. I took the car for about a 15-20 minute drive (83 degree F air temp, 23 C) and then checked the water temperature. I used a digital probe thermometer and an infrared thermometer. They read slightly off from each other but not significantly (just a degree or two Fahrenheit), so I'm giving you the average of the two. At the fill opening with cap off, the temp of the water is 183 degrees F (84 C). On the outside of the upper return fitting on the radiator inside the engine compartment the temp is 171 degrees F (77 C). Interesting that there would be such a difference. I did not check the temp at the fitting at the bottom of the radiator, but will be glad to if this helps. One interesting thing that I never noticed is that the fan blows air forward through the radiator and not back toward the engine. Not sure what to think of that. I may try reversing the fan blade and see what happens. I have Champion W 14 spark plugs which are exact replacements for the AC 78s plugs you have so I don't believe that's an issue. I have a Zenith carburetor on mine. In one of the manuals I have (darn if I can locate the info right now) it lists the carburetors on the 1925 Four as Ball and Ball, Stromberg and Zenith. Though interestingly enough, the owner's manual illustrates and gives adjustment info on a Stewart, even though it does not specifically name it.  Go figure.

 

Beautiful car you have. Mine is not nearly as finished so I doubt I can send pix that would be of any help to you. I 'rescued' it from a gentlemen whose grandchildren wanted to chop it into a street rod. It's a popular thing here in Southern California (and maybe else where) because the pollution controls required are based on the VIN/serial number of the car, NOT the engine. Hence people put a heavily modified big block engine in old cars and don't have to meet any smog requirements.

 

VIV has much more experience than I so that is a voice to which I would pay heed. Best wishes and good luck with your troubleshooting.

Marbeton, 

 

P.S., in my original post I stated I'd read people in that era put lead additives in their cars to prevent pinging. It is true that I read that at least twice, and having not lived in the 20's, I can't personally swear to this. However, in retrospect, l even with 60-70 octane rating back then, I can't believe an engine with such low compression would have trouble with pinging. But again, I wasn't there.😬

Hi Max4Me,

Thank you for your help. Our temperatures are now about 10-15 ° C, so I don't have a problem yet. The engine only overheats when the outside temperature is above 20 ° C. So I'll measure it later and see the difference from your measurement. I have an infrared thermometer and I measure it with that. I usually had about 98-99 ° C on the upper inner side of the cooler. I didn't measure it below, but I'll try to do it when the temperature outside is higher again. The fact that your fan is blowing forward through the radiator is probably wrong. It must suck air through the boiler and push it around the engine through the ventilation openings in the hood. Don't you have a fan mounted upside down? Look at photos of other engines to see if they have it just like you. According to the operating instructions, there should be a Stewart carburetor, Zenith was installed for export only. I am sending you a picture of the page from the instructions where it is written. We have to put the lead additive there because the lead lubricates the valve seats. This is not possible in unleaded petrol and the valve seats would break out.

marbeton

Edited April 19, 2021 by marbeton (see edit history)

[Max4Me]

This is interesting. As I noted before, my car was built in Canada, after Chrysler bought out Maxwell Motors but before everything was nameplated 'Chrysler.' My car has (is!) somewhat of a mystery. Your car has a FEDCO plate on the dash, mine only has a "Maxwell/Chrysler" serial # tag on the firewall inside the engine compartment. Your manual on p. 55, 'SPECIFICATIONS' clearly lists a Stewart carb with Zenith for export. My 'SPECIFICATIONS' page is p. 61 and only says, 'Vertical type, adjustable.' My manual is a second edition, August, 1925, published by The Chrysler Corporation of Canada, Ltd.,Windsor, Canada. Therefore, I have to conclude that your car was built in America, and mine, having a Maxwell plate, a different manual, a Zenith carb and built in Canada, had to be considered and "export." What has this to do with your cooling problem? Beats me!🤨 I just found the different manuals of interest and thought I'd share the oddities with you. I sincerely hope you get it solved. I really enjoy driving mine and want you to be able to do the same with yours.

 

[C Carl]

On 4/11/2021 at 3:31 PM, viv w said:

Hi Marbeton,

 ......................................

 The last thing I recently read about is the octane fuel you are using, and I believe this may be why my cars exhaust got red hot. The old cars had low compression engines, that during their heyday used fuel with probably an octane rating of about 65. Todays modern fuel has octane ratings of 85 (regular) and 93 or 95 for super grades. They say the low compression motor, when using high octane fuel, does not burn all the fuel inside the combustion chamber and when the exhaust valve opens the still burning fuel gets pushed out the motor into the manifold. This can cause a motor to run hot and may explain why my manifold got red hot. They say use as low an octane fuel as you can buy and even suggest lowering the octane by adding some paraffin up to 20 percent. I have not tried this out, so I'm only telling you what I have read. Perhaps google this subject , I came across it when researching problems with ethanol/ alcohol fuels .

Regards

Viv

 

The octane police are on shift change, but are kind enough to issue a correction anyway. Octane in the mid ‘20s was in the mid 40s. And yes, indeed, a low compression engine cannot extract all the BTUs from too high octane fuel. Therefore the EGT is too high, you can burn your exhaust valves also. We learned this in flight engineers school 55 years ago. There were still some recip’s making money back then, so we learned a bit about them. Were taught not to take on any more too high octane fuel than needed at an intermediate airport refueling stop if the proper lower octane was not available. Could burn the exhaust valves. I wish I could afford a DC-6 to play with. 72 cylinders, 11,200 cubic inches to keep you busy.    -    Carl 

[marbeton]

3 hours ago, C Carl said:

The octane police are on shift change, but are kind enough to issue a correction anyway. Octane in the mid ‘20s was in the mid 40s. And yes, indeed, a low compression engine cannot extract all the BTUs from too high octane fuel. Therefore the EGT is too high, you can burn your exhaust valves also. We learned this in flight engineers school 55 years ago. There were still some recip’s making money back then, so we learned a bit about them. Were taught not to take on any more too high octane fuel than needed at an intermediate airport refueling stop if the proper lower octane was not available. Could burn the exhaust valves. I wish I could afford a DC-6 to play with. 72 cylinders, 11,200 cubic inches to keep you busy.    -    Carl 

72 cylinders, 11,200 cubic inches, ooh it must be a wonderful sound.

[marbeton]

8 hours ago, Max4Me said:

This is interesting. As I noted before, my car was built in Canada, after Chrysler bought out Maxwell Motors but before everything was nameplated 'Chrysler.' My car has (is!) somewhat of a mystery. Your car has a FEDCO plate on the dash, mine only has a "Maxwell/Chrysler" serial # tag on the firewall inside the engine compartment. Your manual on p. 55, 'SPECIFICATIONS' clearly lists a Stewart carb with Zenith for export. My 'SPECIFICATIONS' page is p. 61 and only says, 'Vertical type, adjustable.' My manual is a second edition, August, 1925, published by The Chrysler Corporation of Canada, Ltd.,Windsor, Canada. Therefore, I have to conclude that your car was built in America, and mine, having a Maxwell plate, a different manual, a Zenith carb and built in Canada, had to be considered and "export." What has this to do with your cooling problem? Beats me!🤨 I just found the different manuals of interest and thought I'd share the oddities with you. I sincerely hope you get it solved. I really enjoy driving mine and want you to be able to do the same with yours.

 

My Instruction Book is for cars according to No. F-1001 up made in Detroit. According to FEDCO, my car was actually made in Detroit in September 1925. The numbering for cars made in Canada was different. I am also sending you a table with the serial numbers and places of production. I used to get it here on the forum. Our cars should be basically the same, only with small deviations according to the year and place of production. But the main thing is definitely the same. It should be nice with us today, so I'm getting ready for a little test drive. I'm going up a long, long hill to see what it does. I mounted a thermometer there (I made a replica of a Boycé motometer with a mounting on the steering wheel) so I can monitor it continuously. So I'll see what it does.

marbeton

[stakeside]

Great discussion.

I have a new long block Dodge DA-6 completely cleaned out with acid dip, 4-blade fan, 160 degree thermostat, and a water pump. After about 3 miles the water temp goes to 200 +. Is this possibly a timing problem? I have Autolite 3076 plugs and not sure what is AC or Champion equivalent. 

[marbeton]

If your temperature fluctuates after a short drive, it will be:
1)Thermostat. 
  Try to disassemble it, test in a container with hot water and a thermometer to measure when it opens 
  and when it closes.
2)Water pump 
  you have to disassemble and check

3)The radiator may be clogged 
  You have to clean it and test it by pressurizing. If that doesn't help, it has to be replaced. 
  I have to do that with my car now.☹️

5)If you don't lose water from the radiator, the seal under your cylinderhead is OK

Spar plugs equivalent can you find here:

https://www.sparkplug-crossreference.com/convert/AUTOLITE/3076

 

Good luck with reparatur

marbeton

 

 

[viv w]

Just a word of caution. 

Antique cooling systems did not run a pressurised system, if you are having the radiator cleaned, make sure the repair shop you take it to know about antique radiators.

Vintage radiators should be tested for leaks with no more than about 2 PSI pressure, if they test them using 15 to 20 PSI, as they do with modern radiators, it will most likely destroy the core.

Viv.

[marbeton]

• 
• Members
• • 827

Posted 46 minutes ago

Just a word of caution. 

Antique cooling systems did not run a pressurised system, if you are having the radiator cleaned, make sure the repair shop you take it to know about antique radiators.

Vintage radiators should be tested for leaks with no more than about 2 PSI pressure, if they test them using 15 to 20 PSI, as they do with modern radiators, it will most likely destroy the core.

Viv.

• 
• Members
• • 827

Posted 46 minutes ago

Just a word of caution. 

Antique cooling systems did not run a pressurised system, if you are having the radiator cleaned, make sure the repair shop you take it to know about antique radiators.

Vintage radiators should be tested for leaks with no more than about 2 PSI pressure, if they test them using 15 to 20 PSI, as they do with modern radiators, it will most likely destroy the core.

Viv.

Yes you're right. I had the cooler cleaned in a professional 
workshop, which, in addition to modern, repairs radiators for 
oldtimer as well. This pressurization is there only to detect 
liquid leakage or radiator permeability.

marbeton

[stakeside]

8 hours ago, marbeton said:

If your temperature fluctuates after a short drive, it will be:
1)Thermostat. 
  Try to disassemble it, test in a container with hot water and a thermometer to measure when it opens 
  and when it closes.
2)Water pump 
  you have to disassemble and check

3)The radiator may be clogged 
  You have to clean it and test it by pressurizing. If that doesn't help, it has to be replaced. 
  I have to do that with my car now.☹️

5)If you don't lose water from the radiator, the seal under your cylinderhead is OK

Spar plugs equivalent can you find here:

https://www.sparkplug-crossreference.com/convert/AUTOLITE/3076

 

Good luck with reparatur

marbeton

 

 

 

Thanks for options.

I have the original honeycomb radiator and there are no leaks.

From your list it appears I need to get the radiator cleaned and checked for possible clogging.  The problem of flushing is that only say 25% of the tubes are clogged and it is hard to get those tubes cleaned.

I will use a commercial radiator flush. I believe Prestone has one.

Any ideas appreciated .

[stakeside]

I will use this high capacity thermostat. I got it at local Napa dealer. Also need to check timing with a vacuum gauge

Checked on replacing the honeycomb radiator. Cost $1500 + and not readily available. 6 mo back order. 90 yr old radiators not too efficient. The solder breaks down and does not provide positive connection to the fins that transfer the heat. Other option is to replace core with heavy duty brass unit. Cost $1200 but more available.

[viv w]

Stakeside,

I have no idea what is the correct spark plugs for your car, but I do know that the wrong heat range of spark plugs can cause a motor to get overheated in a very short distance. Make sure the plugs you are running are the correct ones.

 Ignition timing, a lean mixture, cracked inlet manifold , leaking manifold gaskets, can all cause it to overheat.

[ArticiferTom]

Stakeside you may want to try the Thermocure /Evaporust cleaning first . Most of what you get blocking is rust particles and this dissolves that and engine rust for better heat transfer .

  Also the DBC web site has sparkplug info for engines ,on the sidebar heading .

[marbeton]

I think a miracle happened. I adjusted the valves and the engine began to cool. 😀😀
This means that my radiator is OK and there was an error in adjusting the valves. 
The cylinders were probably badly rinsed and the mixture burned more than it should.Otherwise I can't justify it.
I didn't do anything else with the engine, so that must have been the cause.

[Max4Me]

Hi, Marbeton.

I've been off for a while. I've been wondering if you'd solved your cooling issue.  I'm glad to see you did.  It's interesting it was a valve adjustment. Hey, whatever works! Congrats, and enjoy your cool drives!

[marbeton]

I also can't believe it, but since I adjusted the valves, the temperature has been fine. 
The old, experienced mechanics justified this to me by saying that this can happen with SV distributions, 
because the cylinders do not wash well.