Restrictor washer instead of t-stat

[Old Henry]

Guys, (and gals if you're out there) apply the law of thermodynamics and this is the truth of the matter:

The only difference between water moving through the engine slower or faster will be the temperature of the water going into the bottom of the engine compared to the temperature of the water coming out the top. If the water's moving slowly such that it stays in the engine block and radiator longer, then the water going into the bottom of the engine will be much colder than the water coming out the top because the water in the radiator has had more time to cool while, at the same time, the water in the engine has had longer to heat up. That's all. That average temperature of the water in the middle of the engine is going to be the same regardless of the speed that the water is moving through the block. If the water is moving faster and spends less time in the radiator and engine block, the whole water temperature in the block will be more even because the water coming in the bottom will be warmer because it hasn't spent so much time in the radiator while, at the same time, the water coming out of the top of the engine block will be cooler because it hasn't spent so much time in the engine. But, the average temperature of the water in the middle of the engine block will be the same as moving the water slower. That's the only difference in moving water faster or slower is how evenly the temperature in the engine block is, not how hot or cold it is overall. So, decide how even you want the temperature of your engine to be and move your water accordingly.

The overall temperature of the engine block is not affected by the speed that the water moves through it. The only way to transfer more heat to the air through the radiator is to improve the transfer of heat from the engine block to the water by eliminating corosion that inhibits that, and, likewise, eliminate such corrosion from the radiator tubes. Then, ultimately, to really cool more, you've got to just plain have a bigger radiator and/or move more air through the radiator!

[bobscogin]

Originally Posted by Old Henry

However, I don't think the speed of the water moving through the system is near as critical as the conductivity of the heat transfer surfaces, namely, the internal surfaces of the engine block and the inside and outside of the tubes in the radiator. If any of those surfaces have any deposits that would interfere with the transfer of heat, then eveything gets hotter.

I know it's widely accepted that build up on the walls of the water jacket will cause an engine to run hot, but that seems counter intuitive to me. If you inhibit heat transfer into the coolant, how does that add to the BTU load on the radiator? If the cooling jacket deposits, prevent transfer of heat to the coolant, then the heat remains in the engine, where it will eventually increase the temperature of the oil, but the sum of BTU's produced by the engine doesn't increase. What am I missing?

Bob

[Old Henry]

Originally Posted by bobscogin

What am I missing?

Read my revised and inspired explanation using the law of thermodynamics. That is the truth of the matter and I don't think anyone can disagree.

[Jack E/NJ]

Old Henry sez "The overall temperature of the engine block is not affected by the speed that the water moves through it."

So what happens to the overall temperature of the engine block if the flow speed of the water is zero?

Jack E/NJ

[Old Henry]

Originally Posted by Jack E/NJ

Old Henry sez "The overall temperature of the engine block is not affected by the speed that the water moves through it."

So what happens to the overall temperature of the engine block if the flow speed of the water is zero?

Jack E/NJ

Ah, you think you have me there but speed implies movement. I wouldn't call zero a speed. That's like calling white a color.

Of course there has to be some movement but the difference between having thermostats or not or having restrictors or not or having stock pumps or Skips, won't affect the overall temperature of the engine. Whatever time the water has to heat up in the engine it also has to cool down in the radiator. It's the law of thermodynamics. There are a lot of things that can be done to cool the engine more efficiently but moving the water faster or slower through it is not one of them. That's the bottom line.

[Jack E/NJ]

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Old Henry counters---"I wouldn't call zero a speed."

OK then. What if the washer only has a pin-hole size opening that allows a trickle flow? Not zero. But a very slow speed. Not pure white. But a little gray. What happens to the overall block temperature then?

Jack E/NJ

Jack E/NJ

[Old Henry]

Originally Posted by Jack E/NJ

Old Henry counters---"I wouldn't call zero a speed."

OK then. What if the washer only has a pin-hole size opening that allows a trickle flow? Not zero. But a very slow speed. Not pure white. But a little gray. What happens to the overall block temperature then?

Jack E/NJ

Jack E/NJ

There is a speed below which the water cools to air temperature before it gets to the bottom of the radiator and gets no additional cooling by continuing it's journey. At that speed, it would be the same as blocking off part of the radiator because it is no longer useful. That, of course, reduces the transfer of heat from the engine to the air moving through the radiator just the same as blocking off part of the radiator and the engine temperature rises. That is precisely how the thermostats maintain a constant temperature, they progressively restrict the flow until it's not enough to keep up with the heat of the engine so it heats up, then they open just enough so that the flow keeps up etc. etc. Of course, if you reduce the speed of the water moving through the system to the bare minimum to use all of the radiator, you will have a vast difference between the temperature of the engine at the bottom and the top of the block. I don't think that can be good.

So, I wouldn't put a washer with a pin hole in the system. That would just be dumb. At the same time, spending extra money on water pumps that move the water faster might be just as dumb.

[Ken/Alabama]

G.M. Tell it it like it is. I drive my 40 all over the place summer and winter . I run a 4# cap on mine to keep the water in the radiator. This business about washers and knocking off every other fin on the water pumps might have worked back in the day when they were running stock radiators that were vented to the atmosphere may have slowed the water down from overflowing throught the overflow pipe. I have plugged off the top of my radiator so I can run a pressure cap. Been doing this for years and no problems even in the heat of the summer.

[G.M.]

Henry I hate to tell you but your all wet. It's not the speed of the water it's the volume. it also requires plenty of air througth the radiator directed through the fins and not around the edges. I have recorded water temperatures on a 90 degree day on a 4 mile streatch of road with about a 12 or 15 mile wind. Going into the wind at the same speed as going with the wind directly from the rear. Going into the wind which requires more work from the engine the water temperature is about 8 to 10 degrees cooler than with the wind pushing the car with less required power. Into the wind provides much more air. The more air forced through the raditor with a good flow of water through it the cooler the engine runs. My information posted here isn't from what I think should happen or guess work this information comes from solveing and correcting over heating problems on well over several thousand 32 to 53 Fords with over heating or running up near or over 200 degrees problems. This was over the past 10 years and there are still 2 or 3 every day. This isn't like a guy with one car it is a broad spectrum of Ford cars and in many cases going back and forth gettting information back and having the person with the problem performing tests and reporting back with the results. In very bad cases of over heating it usually results from a compression leak. I also live where it's usually between 80 and 100 most of the year and developed products like the coil and pumps so I can drive my old Fords any time to any place or any distance and don't have to worry about it starting or running hot. I have put over 108,000 miles on my 39 convertible over the past 30 years and another 100,000 or more on the 39 P/U and 5 or 6 other old Fords I drive almost daily. These all start as soon as I touch the starter all the time, hot or cold and run less then 185 in 105 outside temperatures driving down the road. G.M.

[Old Henry]

Originally Posted by G.M.

Henry I hate to tell you but your all wet.

Wow! Did I bring some out of the chute. What's the deal? There's nothing that either of us have said that disagrees with the other.

I said it's not the speed of the water and you said the same.

I said more air cools better and you said the same as illustrated by the difference between going with the wind or into the wind.

So, where's the beef?

Maybe you ought to re-read what I said a little more calmly. I think that you will find that we are on exactly the same page. I do exactly the same as you do and get exactly the same result. I didn't read anything about you sticking washers in your cooling system or buying "faster" pumps or chopping off fan blades to make things better. That's all that I was trying to enlighten people on so they could be relieved of those myths.

[Old Henry]

Originally Posted by G.M.

It's not the speed of the water it's the volume.

I do need to express a limit to the volume thing that I don't think you will disagree with.

Once the system is full of water, no additional water in the system improves anything. If you somehow plumbed an extra 5 gallon reservoir into the system, (which I haven't read you advocating) provided it was insulated and not providing any cooling to the water in it. It would not increase the cooling capacity of the cooling system any. Now, if the RADIATOR volume and corresponding cooling surfaces were increased, THEN you'd be making a difference. But, it would not be a function of just the volume of water in the system but, rather, the volume exposed to the air in the radiator. Once again, as you have said before, it's the volume of air going through the radiator that really improves the cooling capacity more than most anything else.

[G.M.]

5 gallons more water in the system would increase cooling. For instance a larger radiator tank. More water in the system, more water pumped through the system or more air throught the radiator will all improve cooling. The guys that used the 3 lb valve and got better cooling as just posted was a result of more water KEPT in the system. Running a gallon low makes it run hot. G.M.

[Old Henry]

Fortunately, any myth that adding more water than the system was designed to hold will make things better hasn't really sold very well. At least no one that I know has bought into such a thing.

For sure a gallon less than the system was designed for will have a negative result. But trying to squeeze in a gallon more certainly won't help without also increasing the radiator size and/or increasing the airflow.

[trainguy]

The engine is a machine the transfers energy from gasoline to motion and waste heat energy[BTU's]. The coolent transfers the BTU'S from the engine to the radiator which transfers the BTU,to the air.A gallon of water will absorbe a certain amount of energy depending on the pressure of the coolent before it boils.So the volume of water flowing thru the system has to be able to absorb the engines BTU out put without boiling.The radiator has to be able to transfer all of the formentioned BTU"s from the water to the air. Therefore if you raise the coolent temp you transfer more BTU's per gallon of flow,if you raise the flow you increase the amount of BTU,S the system will transfer.The radiator again must be able to transfer all of the energy to the air. a thermostat is a variable restrictor which controls the volume of energy transfering from the engine to the radiator there for raising and lowering the block temp,this is accomplished buy controling the coolent flow.The fixed restricter does the same but the flow is not variable therefor it will limits the transfer of energy to a fixed amount.Engine crud will slow down the transfer of energy from the engine to the coolent thus raising the cylinder temp.Crud in the radiator reduce the BTU transfer from the coolent to the air. The cooling system is a combination of variables inter cting with each other.Simpley put a properly designed cooling system has to be able to transfer all of the waste energy of the engine to the air otherwise it overheats.

[Frank The Plumber]

The washer is causing more harm than good, the cavitation effect will cause negative pressure resulting in the creation of bubbles, the bubbles will slow the water down, then again this is what a T stat does, you run a t stat because your engine has an ideal operating temperature, below that temperature and you have problems with operation of the engine. The boiling point is raised with higher pressure, just as it requires a higher temp to boil water at sea level, so yes, a 7 lb cap boils slightly higher than a 4 lb cap. If you need to get a gain in boiling point of 5 degrees you have troubles. I have home boilers operating at 215 degrees on a 40 pound pressure and they still remain hydronic and do not break to steam.
Last block I salvaged, I put the bare block and bare heads in a bath of vinegar to eat the rust, had it tanked and scoped it. Put a set of good pumps on it and a fresh radiator, with a clear coat on it, not black. Runs cool. I think a lot of guys are running plugged up old stuff.
This paint a radiator black thing needs to go to Mythbusters, especially since the coating they are using is bitumin and not paint. How would anything run cooler and dissipate heat faster through a coating of light tar? I run aluminum radiators, sure its not traditional or period correct but with the heat transfer properties of aluminum I never overheat, in fact i have to switch to a 185 stat in the winter or it runs too cold. For copper radiators I always order mine bare, I put a light coat of clear or a light coat of black primer on them, just enough to cover the copper and protect it from road salts. Every single hydronic system I have ever seen has been bare tube, bare fin, even bare iron, so why would you insulate the radiator on a car with paints and tars?
If you run straight water in a cooling system of any type, you will get a patina inside the piping of any type of metal, iron oxide for steels and irons, aluminum oxide for aluminum and copper oxide for copper, all oxides block thermal heat transfer and limit flow. You absolutely must use some type of an oxide inhibitor to prevent this surface oxidation within the engines cooling system. Once this occurs on boilers we do a boiler flush, we use a highly corrosive acid and flush the rust out, on a mono metallic system we can do this easily, we only have one metal type usually a tough and stable iron, on systems using more than one metal you are limited to using a chemical that would be compatible with the least noble metal, an aluminum or copper flush chemical. The problem arises that a chemical that will safely de oxidize copper does not do much to deoxidize iron, at some point disassembly has to occur to deox the iron.
While it may sound like two different topics it truly is not, hydronic heat transfer is just that, whether you apply it's principles to a home or industrial application or an automobile the principles are the same. Be cool , Frank the Plumber.

[G.M.]

Old Henry I have built a water pump test machine, tested the flow of pumps and did controled tests of engines for hundreds of hours over a 10 years period on flat head Ford engines. The results I state are tested, documented and proven not what "I think", "Should happen" or WAGs. Why don't you make provisions to add 5 gallons of water into the system, run some tests and report accual results. On the first pump impeller modification on the 33 phaeton which was over heating Purple Ice was first instaledl after 8 or 10 static tests under the same controled conditions everytime. The over heating was the same everytime with the temperature going to 229 with the cap off and would spit 3 or 4 quarts of water. When the Purple Ice was installed the temperature went to 217 sat there about 10 minutes and the temperature came down slowly over a 20 minute period to 207. This was obserbed on a laser pointed gun as the temperature dropped. Every time we ran it after that it only went to 207. That being to hot I modified the impeller on one 33 head mounted pump. On the water pump test machine the stock 32 to 36 pumps deliver 55 gallons each in 5 minutes. This modified pump showed 92 gallons in 5 minutes. Only having one pump it was installed on the right head and the test was repeated. The flat head engine has two separate cooling systems, left and right connected only in the radiator. On this test the right side water comming out of the modified pump to the radiator was 180 and the left side with the stock pump was close to 207. The modified pump was swapped to the left side and the left side ran at 180 and the right side went up to 207. As far as I was concerned this was positive proof that more water pumped through the system was the solution to cool these engines. Without any hesitation I had a multible impeller pattern made and had a foundry cast the new imellers. The rest is proven results by the thousands of people who installed these pumps with most engines running in the range of 25 to 30 degrees cooler. The 37 to 53 pumps was more difficult. At least 10 differant style impellers were made and tested on the machine over a long period of time with no or very little improvement to increased water flow. These were never tried on engines as I knew from the 33 impeller what the results would have been. I got the idea of a turbine type impeller and it took about a week to machine it. The body of the pump also needed to be machined to the same 22 degree angle as the impeller for the impeller to be most efficiant. The clearance between the impeller is critical and every pump is carefully set for shaft clearance, impeller clearance and spring pressure of the seal. Each pump is tested for at least 5 minutes on the test machine for gallons pumped and leaks. At the end of the test 15 pounds of pressure is put in the system to check for any leaks should the pressure get to high in the system when on the engine. The stock 37 to 53 pumps deliver 65 gallons each in 5 minutes some 49 to 53s may go up as high as 70 gallons in 5 minutes. The modified pumps with the turbine impeller deliver 92 gallons in 5 minutes. With the controled clearances every pump tested delivers the desired 92 gallons. There have been some exceptions. These were some of these new after market pumps that were sent in to be modified. After being modified the flow was down in the 50 gallon range. The pumps were disassembled and random deposits of cast iron material was found internally in the pumps blocking the water passages. A hole was drilled in the bottom and with a long shaft carbide tool the excessive material was removed and the hole welded. These pumps were reassembled, retested and came up to the 92 gallon flow requirement. Pumps that are mass produced, not flow tested, shipped and installed for the end user to test may not work as good as the old pumps that were replaced. G.M.

[G.M.]

Frank, Good info. The inside of the radiator is important. By accident I discovered that running Barrs stop leak with aluminum granulars over a LONG period of time cleans and polishes the tubes and top plate of the radiator. It may also provide some cleaning of the block but I can only report on what I see. The picture is of the radiator shown is of my 39 convertible with 108,000 mile over the past 30 years. The radiator was rebuild over 20 years ago and the Barrs heavy duty aluminum stop leak installed maybe 10 or 12 years ago?? About a year ago I drained the radiator down some to replace the top hoses and noticed the shinney top plate and tubes. After changing the hoses I took my drain pan and watering can and pulled into the radiator shop and drained the water down to expose the top plate. The owner who is a friend of mine came over and asked what was going on. I told him I should of known better to let him rebuild the radiator. When it got down to where we could see the plate and tubes he said he never saw a radiator like that and said I must have something that removes electrolisis. The only thing I had was the Barrs and the fact that the water is being forced through the radiator at a much higher volume with the aluminum granulars acting like a polishing agent??? G.M.

[Tom's36coupe]

Thanks to all for the very detailed explanations on how the flow works in the Flatheads. I did have a set of t stats in a few years ago and they worked ok but then took them out and put the washers in. Seemed to run the same temp after it warmed up. I am running stock style pumps and do use water wetter with a 50/50 mix of Prestone.

[Frank The Plumber]

GM, what ever is in that Barrs formula must coating the internals of the system, it would be interesting to see if the same protection is being given to the iron and if any aluminum components in your system. I would wonder if any type of granulized material could stay in a waterbourne suspension, or if after time it would seek pockets or even break down. I would think that some how you have sealed the metal to reaction with a coating. In reality all systems should look like yours through out. It is very difficult to clean a system to this, much better to maintain from the start.
One of the interesting things I have learned about reactivity in boilers and heating systems is that a low oxygen environment promotes the deterioration of metals.
Low oxygen causes a high acid content, thus increasing the metallic reactivity of the metal, basically making a minor battery of the system, perpetuating the degradation of the metal. Low oxygen also causes a phenomenon that results in exterior oxygen permeation. Ambient environmental air has an oxygen content of about 20 percent oxygen, water has a content of about 2 to 3 percent dissolved oxygen, oxygen has the ability to balance itself in the environment, it can pass molecularly through metals membranes and cell walls. Warm water or liquid hastens this effect, acid water hastens this effect as it creates a reactive battery, reduced redox hastens this effect.
The blocking of oxygen and prevention of the formation of carbonic acid is the most critical part of preservation of a liquid system. The pipes in our homes actually rot from the outside in, O2 passes through the metal into the pipes interior and causes the barnacle that you see as a blockage on the interior of the pipe as you section it for viewing. FTP

[Old Henry]

Originally Posted by G.M.

Old Henry I have . . . tested the flow of pumps . . .

GM. I love what you've done. I am, perhaps, a bit more skeptical of opinions unsupported by actual scientific testing because of my profession (lawyer.) So, I really appreciate you taking the time to explain in detail the testing that you have done.

The resullts of your test seem to support the point that I was making - that moving the water through the block faster will cause a lower temperature of the water coming out of the top of the block because it had less time in the block to heat up. What would have been interesting in your testing would have been to measure the temperature of the water going into the block coming out of the bottom of the radiator to see whether it was, in fact, colder when the water was moving slower and hotter when it was moving through faster. I don't suppose you took that measurement. If so, I'd be interested in your data.

With the outlet temperature of the water being lower with faster water movement, that would also give the illusion, if not the reality, that the engine temperature was lower because the temperature guage actually measures the outlet temperature. Thus, moving the water faster with more efficient pumps would at least give the appearance, if not the reality, that the engine was running cooler.

Even though I suggested that, after a certain velocity of water going through the system is reached, higher velocity no longer cools any better without increasing the cooling efficiency of the radiator; it takes a little more "faith" to believe that at lower, i.e. stock, water velocity, the engine temperature is OK because the outlet temperature where the gauge reads will be higher. Thus, if for nothing more than just the peace of mind that comes from seeing the gauge read lower, it might be worth moving the water a little faster with more efficient pumps.

That is, in fact, what I have done. It wasn't intentional. It was just that the last pumps I bought from C&G were higher efficiency. It can't hoyt.

Thanks again for your patient explanation.