Engine Cooling

[James_Douglas]

If you read my last thread, you can see that I had some cooling issues. Sondra and I spent three days in the Central Valley of California, away from our cool San Francisco, and the car performed well with some exceptions.

I drained the car and put fresh water in it, I also added a bottle of "Water Wetter", and I put in a new thermostat.

It was about 100 to 105 degrees most of the trip between 11AM and 3PM. One the interstate at between 60-70 MPH the car ran at about 180-190 degrees.

In town as long as I maintained a constant 25 MPH it hovered at around 190 degrees. However, if we started driving in residential areas with stop signs every couple of blocks the car went to 200-205 degrees and I got concerned about over heating.

It appears to me that the car just does not have either enough reserve cooling capacity to see the car over any "heat humps" in slow around town use or on very long hill pulls on very hot days AND/OR not enough wind is being pulled over the radiator at slow speeds.

For the issue of reserve cooling capacity, I will have to talk to the radiator folks about that.

As to the fan speed, I am going to look at making a smaller pulley to speed up the fan at low RPM. We have a "old school" pump re-builder in the area that does industrial pumps and he said he has a set of pump bearings that he can install and that with a flathead and a small pulley I would not be able to hurt it.

I am also going to have a fan shroud made.

Best, James

PS, the car ran fine but we melted. Did anyone ever make a set of templates for mounting an A/C compressor on our flatheads ?

[47heaven]

If you read my last thread, you can see that I had some cooling issues. Sondra and I spent three days in the Central Valley of California, away from our cool San Francisco, and the car performed well with some exceptions.

I drained the car and put fresh water in it, I also added a bottle of "Water Wetter", and I put in a new thermostat.

It was about 100 to 105 degrees most of the trip between 11AM and 3PM. One the interstate at between 60-70 MPH the car ran at about 180-190 degrees.

In town as long as I maintained a constant 25 MPH it hovered at around 190 degrees. However, if we started driving in residential areas with stop signs every couple of blocks the car went to 200-205 degrees and I got concerned about over heating.

It appears to me that the car just does not have either enough reserve cooling capacity to see the car over any "heat humps" in slow around town use or on very long hill pulls on very hot days AND/OR not enough wind is being pulled over the radiator at slow speeds.

For the issue of reserve cooling capacity, I will have to talk to the radiator folks about that.

As to the fan speed, I am going to look at making a smaller pulley to speed up the fan at low RPM. We have a "old school" pump re-builder in the area that does industrial pumps and he said he has a set of pump bearings that he can install and that with a flathead and a small pulley I would not be able to hurt it.

I am also going to have a fan shroud made.

Best, James

PS, the car ran fine but we melted. Did anyone ever make a set of templates for mounting an A/C compressor on our flatheads ?

James...I was out driving the P15 today and it was about 102. Being that it's dry heat, it didn't bother me much, but like you, I was dying in the car between the heat outside and the heat generated from the motor going into the cab. I managed to keep the car down below 180, but does not stay the coolest in the stop and go traffic. It got to 200 and when I turned the radiator fan, it cooled it down slightly. I just wonder if this was common for these cars back in their heyday.

[greg g]

Any possibility of plumbing in a heater core somewhere where the heat won't go into the car. Extend the heater hoses and stick it in the air flow some where inconspicuous??

A heater core will provide about 25% more cooling capacity.

[47heaven]

Any possibility of plumbing in a heater core somewhere where the heat won't go into the car. Extend the heater hoses and stick it in the air flow some where inconspicuous??

A heater core will provide about 25% more cooling capacity.

Huh? I don't get it?

[Jerry Roberts]

Huh? I don't get it?

Greg is talking about adding a heater core to act like an additional radiator . Just hook it up in the engine bay somewhere so it can catch the breeze .

[TodFitch]

...snip... We have a "old school" pump re-builder in the area that does industrial pumps ...snip...

Who and exactly where is this fine gentleman?

...snip... PS, the car ran fine but we melted. ...snip...

Most of our summer tours in the old car are toward the coast for this very reason. I may have been born and raised in the Southern Arizona desert but I've been transformed into a wimp by living in an area that has an incredibly nice climate.

[JIPJOBXX]

Well this just goes to show you that our forefathers had this problem when these cars were used everyday. My car does the same thing as your and its the pits to have it get so hot inside but again they've always been this way! Going to the Goodguys car show next Saturday but in the early morning and probably will come back after dusk. Its suppose to be in the 70's, 80's and 90's up here in Washington this week most unusual weather.

[hkestes41]

Might want to consider a fan shroud.

Here is a tech post from the HAMB with a very straight forard method to make a custom fit fiberglass fan shroud.

http://www.jalopyjournal.com/forum/showthread.php?t=380196&highlight=shroud

I started mine today. Got all the fiberglassing done, now I just need to cut it off the boards, sand, putty, sand, paint install.

[grey beard]

Mr. Douglas,

Don't know the history of your vehicle or its engine, but it is my considered opinion that our L6 motors have lots of extra cooling capacity engineered into them from the drawing board. I have overhauled several of these engines and found without exception that when the block core plugs on the driver's side are removed, a lot of debri has collected in the lower level of the water jackets over the past years.

I'll bet that if you remove your water pump and pull the water distribution tube, and then knock out the four or five block plugs and flush things out with a garden hose and shop air, you will be amazed at the crud you find coming out of the bottom of your water jacket.

Do this and put 'er back together, and you will find no need to speed up the fan or water pump, or add a shroud. The eingineering's already in place. Just clean things out so it can work.

My fresh Pilothouse engine can sit in traffic all day in summer heat and the dash gauge never goes over 180 - and that's with a 180 degree stat. Our engines all share the same cooling system design.

Check it out. Good Luck:)

[James_Douglas]

Dave,

My engine has less than 10K on it. When it was taken down for rebuilding all plugs and the distribution tube were removed. The engine was taken to an acid dip house and the block was dipped to make sure it was as clean as possible. It was then tanked again at the engine shop.

A new distribution tube was put in. A new water pump has been put in. The radiator was re-cored.

The engine is not running lean. The oil pressure is at 40 PSI.

The engine temperature runs fine until the ambient temperature hits about 90 Degrees. At that point, for every 1 degree the ambient goes up, the engine goes up about 1 degree. So that on a 100 degree day, at running speed, the engine seems to hit about 190.

The slow speed heating, below 24 MPH, in stop and go driving is no doubt due to the need of a shroud and/or a smaller pulley to move the fan a little faster.

The running speed increase, tells me that the reserve capacity is just not there or the engine would not go over 180. In my case the compression ratio was raised beyond the factory specifications and that can contribute to more heat output.

It is possible that the inside of the engine block is not as clean as necessary. However, given all the steps during the rebuild to clean the inside of the block, I doubt it. Acid dipping should have removed more stuff that just about any other method. When it got back, I also ran a hose in it and ran steel rods everyplace I could to flush it.

Given that a number of people that have noted cooling issues, I do think that cooling issues may be because of a lack of reserve capacity. Reserve capacity is not only to deal with short term increases in engine heat out put, but also long term issues like dirty blocks.

If you read the link I posted about the man who purchased a new 1952 Desoto and ran it across the US with a trailer, he had cooling issues from day one when the car was new. Pulling a trailer is also a reserve capacity design issues.

If the original designers cut the circulation tolerances so close that an acid dipped block is not clean enough to cool properly, then I would consider that a design defect as far as longevity is concerned.

I will keep at it and see what I can do to have a cooling cycle that works as well as yours.

I hope that people do keep chiming in with ideas.

James

[grey beard]

Okay,

Sounds like you've been there ahead of me. You've obviously done everything right. My only thought is that my pickup may have a much larger radiator than the cars had. In this case, a shroud or a pusher fan may be a logical consideration.

Please keep us posted as to what you find works best for you. And, yes, I did read the interesting DeSoto article. Very well written and interesting.

Good luck finding the culprit.

[Don Coatney]

James;

As I have said before your 60+ year old car will not perform as well as a modern car. If you want a car that will not have problems then buy a new car. I am not afraid to drive my Desoto powered Plymouth in the heat of the summer with no "reserve" cooling capacity. So it goes well over 200 (gage reading) for short periods of time. It soon recovers and drops down to a more aqcceptable heat range. Live with it, drive your car, and enjoy it.... No need to reinvent the wheel.....

[JIPJOBXX]

Just a passing thought? Could you make a basket out of something and put dry ice in it to cool oft the engine. Sounds kind of silly but why not? You can buy dry ice at most any store now and try it out? I was just thinking of putting some in my swamp cooler and see what happens? I know, I know carbon dioxide but my car is not tight by any means.

[Dennis Hemingway]

Maybe you need a Desert Water Bag full of water to hang in front of your radiator.

There is one on E-Bay that's from san Francisco.

http://cgi.ebay.com/VINTAGE-DESERT-WATER-BAG-SAN-FRANCISCO_W0QQitemZ330344292184QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item4cea0ddf58&_trksid=p3286.c0.m14&_trkparms=65%3A12%7C66%3A2%7C39%3A1%7C72%3A1205%7C293%3A1%7C294%3A50

Dennis:D

[Reg Evans]

Greg is talking about adding a heater core to act like an additional radiator . Just hook it up in the engine bay somewhere so it can catch the breeze .

I have done this in the past and it does help.

[Joe Flanagan]

I had my engine dipped as well, and when I got it back, I shot water into every opening I could find. I did get an incredible amount of crud out of it even after the shop had dipped it. In fact, I couldn't believe how long it kept coming out and how I'd always find more if I tipped the block to a different position or shot water from a different angle.

[PatS....]

My Uncle and my Dad used the old 49 Chrysler as a daily driver including summer holidays into the Rockies with Mom and 3 kids towing a tent trailer.

I don't recall any overheating problems at all back then and I drove it as a DD much later and had none.

It does get hot here in the summer...in the 90's right now...so these cars did not have inherent bad cooling systems.

Near Radium BC 1957ish (also towed a tent trailer there)

[55 Fargo]

James;

As I have said before your 60+ year old car will not perform as well as a modern car. If you want a car that will not have problems then buy a new car. I am not afraid to drive my Desoto powered Plymouth in the heat of the summer with no "reserve" cooling capacity. So it goes well over 200 (gage reading) for short periods of time. It soon recovers and drops down to a more aqcceptable heat range. Live with it, drive your car, and enjoy it.... No need to reinvent the wheel.....

I gotta agree with you Don, no matter how well these engines have been preserved or rebuilt, will not perform as a modern engine, and drivetrain.

I think your bang on. these engine will get running much hotter in 90 and over ambient temps, even at 80+ my engine will run warmer than at 40 to 70 degrees. Running at 185 to 195 ain't so bad, it may be a little alarming, but not so bad, our modern cars run much hotter than this. This is one reason you don't see hardly any cars pulled over and boilin over, I saw a lot of this as a kid, and I'm only 47.

James, your temps were running hotter in the super elevated ambient temps, but you did not boil over, did you lose power, was the engine hard to start, what real negative thing happened? You car sounds to me like it is doing fine, and is performing very well in super hot weather.

I know a guy up her who owns a couple of T & Cs, one with a 6 cyl, he was concerned as he hit 200 once last summer, he has a rebuilt engine, well maintained car, re-cored rad, a 160 degree t/stat. He thought because he had a 160 t/stat and he ran at 185 to 200 on a hot day, he thought there was a problem, well you could have a 100 degree t/stat, your t/stat will open fully, and the engine will find it's own temp based on engine cooling system efficiency, outside ambient temps, engine load, terrain, speed/rpm, and air flow across the rad.

Greybeard (Dave), running these flatheads should be okay 180 to 200 according to your great thread on "Thoughts On Flatheads". I though it was you who was considering going with a 190 or 195 t/stat, did you ever do this?

If your truck is running at 180 on hot days, would you still want it to run hotter say 195.

I also think once the engine temp gets higher, say 190 to 205, the rad is under a much heavier load to cool this coolant down beore it returns to the block. Once engine temps rise above 200, it may be difficult to cool down, without a good airflow throught he rad, via,wind,fan, or pusher fan.

Sometimes we just gotta pull over and take a break to cool down.

Todays engine run at way higher temps, with 50-50 antifreeze and water, to raise the boiling point, as well as the 16 lbs rad pressure, so going to 210 or 220, is probably not as abig a deal as doing this with a 60 year old flat head engine and non-pressurized cooling system.

A very interesting thread..........Fred

[55 Fargo]

My Uncle and my Dad used the old 49 Chrysler as a daily driver including summer holidays into the Rockies with Mom and 3 kids towing a tent trailer.

I don't recall any overheating problems at all back then and I drove it as a DD much later and had none.

It does get hot here in the summer...in the 90's right now...so these cars did not have inherent bad cooling systems.

Near Radium BC 1957ish (also towed a tent trailer there)

Pat, the engine could have very well been running at 180 to 195 degrees, and most likely had water in the rad, with maybe some water pump conditioner.

They probably ran alcohol based antifreze in winter, and a 160 t/stat, then either a 180 t/stat and water for summer, at least until Prestone became common.

But hill climbing on hot days in BC with a car load, would no doubt elevate engine temps.......Fred PS love the pic

Edited July 20, 2009 by Rockwood

[James_Douglas]

Does any know what the size of the crankshaft pulley's are and the size of the water pump pulley ?

As close as I can tell with them on the engine my crankshaft pulley is about 5.25 inch and the water pump pulley is 6.75 inch.

With the larger water pump pulley the shaft speed on the pump is about 370 RPM if I did the math correct. I seem to think that my older wider pulley on the water pump was smaller than the thinner V on the current pulley.

James

[55 Fargo]

Does any know what the size of the crankshaft pulley's are and the size of the water pump pulley ?

As close as I can tell with them on the engine my crankshaft pulley is about 5.25 inch and the water pump pulley is 6.75 inch.

With the larger water pump pulley the shaft speed on the pump is about 370 RPM if I did the math correct. I seem to think that my older wider pulley on the water pump was smaller than the thinner V on the current pulley.

James

I can go measure 1 on a 251 if you want me too, gonna get bit by the skeeters for you.....Fred 1948 Chrysler 251 engine ,the outside diamter of the crank pulley is 6 3/8 inches, the water pump pulley is outside diameter is 6 inches, inside diameter is 4.5 inches, this is a wide belt pulley, hope this helps.....Fred

Edited July 20, 2009 by Rockwood

[Plymouthy Adams]

sometimes you can move the water too fast and not leave it in the block long enough to saturate it with heat to be exchanged at the radiator..

your recore..is is the same as the original honeycomb with the extra water reserve capacity built into it..these sytems are not pressurized and thus deal in volume..

why not close your system and use about 7 lbs pressure cap and increase your operational safety margin by 20 odd degrees..

[greg g]

Again I will recite my mantra, of using a differnt mix of coolant to water, more water.

Or if you insist on 50 50 that gives you a boiling point of 223 ad 7 lbs of pressure pick up another 12 degrees or so, so that give you 25 degrees of reserve over 212, which gives you 30 + degrees of reserve above your noted 200 degrees of occasional operational high.

James was it you who made an adaptation to the bypass plumbing system??? Is there any possibility your bypass port is not closing all the way and allowing coolant to short circuit the radiator and return to the engine without the benefit of passing though the radiator???

[James_Douglas]

Greg,

I swapped in the original bypass (the entire water neck) just to make sure that it made no difference. It did not.

I am suspecting that the water pump is turning slower with my current pulley than the wide belt original. I need to dig through a bunch of boxes to find the wide belt one that was on the car and check the size. A one inch smaller pulley can add 150 RPM to the pump/fan speed.

I doubt that a few extra RPM will cause pump cavitation, put it could pull a lot more air at idle.

Having the core sealed and running anti-freeze/boil would allow an operational reserve. I am only hesitant as I have read about head gasket sealing issues on the flatheads with increased water pressure.

...James

[Plymouthy Adams]

later model flatheads were stock with pressurized systems with no ill effects..mentioning the changing of the belt from stock may indeed have an effect if said pulley is "smaller" than the one in use now...slowly the pieces fall onto the forum..