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  #1  
Old 05-16-2003, 01:25 PM
sanborn sanborn is offline
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How is everyone on this beautiful spring morning?

A few months ago, some requested I publish some info on what we do to our engines to keep them cool under race conditions. We have been working on our all iron "limited" engine for some time and have just about finished all the fabrication/machine work. Hopefully, it will be ready for assembly in 2-3 days. I will have photos taken; but I will rely on my son(mightymouse) to take care of that- I am not very photo oriented( I'm a Kodak "box" camera guy myself-bet Harry is the only one who knows what that is).

So without photos I am going to start this thread with some verbal information.

How does an engine generate heat? It generates heat by friction(piston rings rubbing on the cylinder wall, the camshaft lobes sliding on the flat tallet cam), by pressure(the force of the crankshaft on the oil film of the main and rod bearings, the compression of oil by the pump, etc.) and by the combustion process itself.

How do we cool the engine? Water and oil cools an engine. Water cools the block and cylinder heads. Oil cools the moving parts (crankshaft, rods, valves, camshaft, valve springs, bearings, etc.) The block and heads also cool the oil just by surface contact-so some of the oil heat actually is dispated into the block and heads.

I'm going to talk about water cooling-oil cooling is a complete different subject.

How does water cool the block/heads? I know this is elementary but hang with me. At rest, water is in the block, heads, hoses and the radiator. As heat is generated by the engine, the water is sucked from the radiator, pumped into the engine, pumped out of the engine, through the hoses where it returns to the radiator tank, through the cooling fins of the radiator and finally into the "cooled" tank section of the radiator where it awaits suction back through the engine.
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Old 05-16-2003, 02:00 PM
sanborn sanborn is offline
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Sounds pretty simple? It is as long as you have a pump that works adequately, a radiator that cools the water sufficently as it flows through, no major restrictions, etc. And this is not to hard to accomplish with a "stock" engine, driven on the street(at less than 2500 RPM).

The rub occurs when we take that same "stock" engine, soup it up and turn it more RPM than it was ever designed for. We must soup up the cooling system at the same time.

Let me back up a bit- I said the water is heated by the block and cylinder head absorbing friction, some oil heat and the combustion process. This is true. A race engine generates the same heat by friction and oil as a stock engine---At the same RPM. But when we double the RPM, quite a lot more heat is generated. When we triple the RPM- the comparison goes out of sight! Combustion heat is a little different- it's still affected by RPM- but it's also affected by the HP generated by the combustion process. If you double the HP, you double the heat. True, a lot of the extra heat goes past the exhaust valve but a lot is also absorbed by the head/block.

So here we are, we have doubled the HP turning three times the RPM it was designed for ----And trying to cool it with the "stock" cooling system. This is really where the information begins.

I'm going to stop now-Got to go to work- You know, pays the light bill, keeps new shoes on the race car, keeps Mama happy, etc.- Need I say more!!!!!
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  #3  
Old 05-17-2003, 01:17 AM
sanborn sanborn is offline
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Just like your crazy cousin, I keep coming back! Still no photos but we really don't need them yet.

I want to start with some things I have learned over the years. Don't claim to know everything-I have probably blown up more stuff than I can remember-I just try to not make the same mistake twice. If your opinion is different than mine-great- that's the reason they make Chocolate and Vanilla ice cream. It's just that most of my friends think that "Tootie Fruity" fits me the best.

OK, let's start this off with this comment-Stock Mopar stuff doesn't work well at all under race conditions. It can be made to work well, but not in stock form. If you try, not only will your engine run too hot, cast iron parts will tend to crack.

Let's go to the first part everyone thinks about- the radiator. the stock type brass radiator works pretty good-if it's clean and it flows enough water. Many stock radiators don't flow enough. So, if you must run a brass, stock type, consider at least a three core, as large in surface area as possible. If you can use an aftermarket aluminum radiator(AFCO, Howe, etc.) by all means use one. All of them will handle the cooling requirements under race conditions(up to about 750HP).

Now to the next part- the water pump. A few years ago, I discovered something about stock aluminum Mopar water pumps. Above about 4500 Pump RPM, they don't pump!!!!!!How do I know? I cut the top radiator hose and added a section of clear plastic rigid tubing in order to watch the water flow. The flow actually slowed down above 4500. I found the problem, we can now flow up to about 6000 Pump RPM. I will have photos of that later. I also discovered the left side head was usually 20-25 degrees cooler than the right side head.

The block and heads need a lot of work- the standard water flow is not good, needs to be changed(rerouted) and they tend to create air pockets. Much more about this when the photos are taken(are you listening mightymouse?).

I also want to talk some about the differences between the "R" blocks and standard blocks- and what must be done to get the "R" blocks to run cool.

That's all for tonight, have run out of words.
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Old 05-18-2003, 01:23 PM
355 racer 355 racer is offline
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Biggrin MORE!!

Lets go Sanborn, get your a$$ out of bed. You have had plenty of time to sleep. We are all waiting for the next installment from the 'WATER DEPT. '. If you open them bleery little eyes, you will see momma has got your coffee ready, the dawgs are outside, and you should be full of writing inspiration. Now get it in gear!! 'the old man'
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Old 05-19-2003, 12:28 AM
sanborn sanborn is offline
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Gee Harry, It's only 10:30, that's not late for Sunday-besides it's raining and the dogs didn't want to go out!

Let's talk about water pumps first- actually about water pump impellors. There are two basic types; open impellors and closed impellors. Mopar uses open back impellors. They are cheap to make, don't give much problem and work for general use. The other type are closed back impellors. These are far more expensive to make and are the type generally used for racing applications. The only closed impellor pump produced for Mopars is the Howard Stewart Stage 3 or 4 (can't remember which- anyway it's the most expensive one).

Water takes the path of least resistance. And when you are trying to pump water into an engine if it's easier for water to flow around the side of an impellor(open back) it will. When it flows around the side of the impellor, it's not being pumped into the engine. This is called cavitation. With a closed impellor system, once water gets into the impellors-it's trapped and can't escape because of the closed back. It has to be pumped into the engine. Closed impellor pumps can cavitate also, but at a much higher RPM.

I have found the Mopar type (open) system begins to cavitate around 4000-4500 Pump RPM. The closed system begins to cavitate at 5800-6000 Pump RPM.

The Howard Stewart Pump is nice but somewhat pricey(for the really good one). I have found a little technique that will get the Mopar pump to work ALMOST as good as a Stewart.

Get out a stock pump. You will notice the impellors protrude past the back flange about 1/4". But, if you look at a stock timing cover, you will see the depth from the water pump flange to the back of the timing cover pump housing is about 1/2"-5/8". I don't know why they allow such tolerance but they do. Anyway, this typically leaves a 1/4" to 3/8" Gap for the water to escape around the open back impellors. What I do is cut a round aluminum plate 1/2" larger in diameter than the impellors and TIG weld it to the timing cover.

The photo shows one of our timing covers with the plate TIG welded on. This particular plate was 3/8" thick. Then I carefully measure how far out the impellors protrude, then mill off the excess from the TIG welded plate until I have only .010" clearance. This plus the gasket(.030") gives me about .040" total clearance between the impellor and plate. This prevents almost all the water from escaping around the impellors. It allows the pump to "Keep on Pumping" up to about 6000 Pump RPM. It also helps to equalize the flow to both side of the engine with helps to keep both heads the same temp.
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Old 05-19-2003, 12:48 AM
sanborn sanborn is offline
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I have found over many years of racing that don't want to restrict water flow through the engine. NO RESTRICTORS!!! And, I've found it best to turn the water pump no more than 6000 Pump RPM. So, if you turn your engine 6000 RPM, use a 1 to 1 pulley ratio. If you turn your engine 8000RPM, use a 25% reduction pulley set. If you turn 9000 RPM, use a 33% reduction pulley set.

When you are at maximum RPM, you are generating maximum heat-that's not the time you want your pump to quit working.

Let's review the water flow path through the block and cylinder heads:
Water is pumped into the 1" diameter hole in the front of the block. From here the straightest shot is to the back of the block and the 1" diameter hole there. That's where most of it goes. Sure, some of it goes down to the bottom of the block and goes up into the heads in the row of holes in the bottom of the deck of the block. But most goes to the large hole in the back. This is exactly what you don't want to occur.!!!!!! Block off that 1" hole in the back of the block, force the water down in the block and force it to come up into the heads through the holes in the bottom of the block deck. This maximizes the water flow around the exhaust valves(where most of your heat is). You want to keep your exhaust valve seats as cool as possible.
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  #7  
Old 05-19-2003, 12:56 AM
sanborn sanborn is offline
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OK, I said you want most of the water to flow through your block and up into the cylinder heads in the lower row of holes in the block deck. But, some blocks have a full set of holes, some blocks don't. And, most head gaskets don't have a full set of water flow holes along the bottom.

If you head gaskets don't have a full set of holes-Punch Them!!!BTW, don't try to use a drill, it will tear the gasket. Use a Punch Set. If you don't have one, buy it(about $25-$30).

If your block doesn't have a full set of holes, drill them. Start with a 3/16" drill, gradually get up to at least 3/8". The same for cylinder heads.
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Old 05-19-2003, 12:59 AM
sanborn sanborn is offline
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Guys, I screwed up, put in the wrong photo.
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  #9  
Old 05-19-2003, 01:08 AM
sanborn sanborn is offline
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Now we have the water up in the head. Now where does it go. Standard water flow is out the front of the head and into the intake manifold. That's really not good for racing because the water coming from the back of the block gets hotter than the water coming from the front of the block. Unequal temps in cast iron heads means the possibility of cracking increases. You want the temps to be as consistent as possible.

The ideal way is to bring the water out the front, middle and back of the head with all outlets being equal flow. That's how the aluminum race heads work. But, we must do the best we can with iron. So, we bring a 1/2"ID water line out the back of the intake(in addition to the normal front outlet). This isn't perfect but it does help to keep temps equal throughout the head.
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Old 05-19-2003, 01:24 AM
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You remember that photo of the water outlet in the front of the cylinder head I put in by mistake? Here's why I took that photo. We are installing a set of new 15 degree W2 heads. One of the things I noticed is the water outlet is very small-about 5/8" square. This is TOO SMALL!!!. If you are putting water in the block through a 1" hole(about .750 square inch) you want the water outlet to be as large. So, I enlarged it!

Always look for things like that. The factory isn't perfect but your cooling needs are very precise.

Now, lets talk about "R" blocks!

First, the water inlets are too small-about one half the normal stock size. The factory reduced the size of the inlets in order to allow for decking of the blocks down to 9.00". If you are using an "R" block with the stock 9.60" deck height, you can enlarge the front water inlets to standard size. But, if you are using a low deck block(9.00") you need to find a way to get more water into the block. This is how we did it on our "R" block. It works!
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Old 05-19-2003, 01:31 AM
sanborn sanborn is offline
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Another problem the "R" blocks have(especially the siamize versions- where is spell check when I need it) and even the early "X" blocks is poor water flow(or none) between cylinder walls. This leads to uneven cooling(hot spots) or even worse, air pockets. The best fix is to drill holes in between the cylinder bores in the block, cylinder heads and don't forget to punch holes in the gasket.
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Old 05-19-2003, 01:35 AM
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The Nascar "R" blocks have holes drilled up through the block between the cylinder walls. The holes are quite small (about 1/8"). This helps but should only be attempted by the the brave!
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Old 05-19-2003, 01:49 AM
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Moparvann, sounds like either your water pump is turning too slow at low RPM OR your engine driven fan is not doing a good job. Could be a very lean idle circuit-But I doubt it.

Brian(Dyno 360), I wish we would be ready for this weekend-but not possible! I must finish the rocker arn stands for the 15 degree heads(Jessel doesn't make anything for 15 degree-T&D has a nice set- for $1500! I don't have the $$$ so I am adapting the 18 degree Jessels to the 15 degree head). And, I have only made the exhaust flanges-haven't finished the three stage headers. And, I still must make the mounts for the Belt drive fuel pump. And, I must put together a Dry Sump oil pump. And, I'm sure I forgot something else-just can't remember what it is!!!!
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Old 05-19-2003, 04:11 AM
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What I did was pressed in nipples into the back of the heads and connected the two into one and feed it into the upper rad hose, seems to work for me but I have only a 3-400 hundred horsepower motor, more power equals more heat, right.
I made a power steering bracket out of 1/4 inch and all I can get behind the impellar is 1/4 inch, there isnt room for a plate when the power steering pump adaptor isnt on, is there that much variation in pumps and timing covers that I cant put any more material in there. I also run a dual pass radiator, that makes the thing very efficient, by utilizing the whole radiator, not the path off least resistence like in a normal crossflow which might only be a few tubes.
Cavitation can start at lower rpms if there is a lot of air in the system, for example when you dont purge all the air out of the system, or if maybe your cap isnt enough pressure that the heads turn the water into steam and that is like spitting on something hot, the water or spit, never touches the metal and the metal stays hot or gets hotter depending on the creation of heat.
When water turns to steam the steam takes up roughly 7 times the space of water and that is what causes the pressure increase and pukes the water out the overflow. I run a 25 pound cap and that raises the boiling point by keeping the coolant under pressure and increases the rate of latent heat transfer to the cooler coolant from the heads and oil.
Heat transfer occurs when a cooler mass comes in contact with a hotter mass, until it is even temperature, that is why a steady coolant flow is needed to keep the process going, which in turn is why my dual pass rad is more efficient by holding the water longer in the radiator while still flowing and more air is going over it to cool it off.
I also run a catch can, that way the coolant that is lost can be recovered and it is one less thing I have to check when Im racing, it does the job by itself
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Old 05-19-2003, 03:42 PM
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Have you looked at or tried the FlowKool type of water pump.
What they do is put a solid disk on the impeller to close the pump vanes. I made my own out of .030" shim stock and welded it to a stock 6 blade pump. I really don't know if it helped or hurt.It has'nt been hot enough yet this year to worry about over heating. Just wondered what your opinion was on this type of mod.
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Old 05-19-2003, 09:40 PM
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I am not knowledgeable about the FlowKool pump. From what you describe with the disc sounds like my description of the "closed impellor system". Probably the word impellor was not correct- the term vanes might be more correct.

The one thing about stock pumps is there is still a lot of gap between the pump housing and the vanes on the front side. When I was using stock pumps, I would press the vanes closer to the housing then weld the vanes in place where they couldn't slip backward toward the timing cover. I have TIG welded round discs to the vanes as well. It Helps!

Cageman, you have some good comments. I knew I had left something out. Dual pass radiators really help to cool an engine. We have not had to use them in several years-So I had forgot about them. You don't see them used much in Dirt Late Models except in 430"+ engines, on gas, racing on Sunday afternoons.

On another subject, we use a plain four blade fan, purchased from AFCO, no shroud, spaced about 1 1/2" from the radiator.

When you get your cooling working really well, it will amaze you. You will also discover other problems- like idling too cool, causing throttle response problems when time trials come. We have found it best to totally block off the radiator while waiting in line for time trails, the sheet metal block off is removed just before Jeff goes on the track-that is the only way we can keep the engine crisp.
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Old 05-19-2003, 09:45 PM
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Cageman, I forgot to add, there is at least 1/4" variation in the stock tolerance for impellor location on the pump shaft. We have three different pumps in the shop, and they all have been moved so we can get consistency(interchangeability) between pumps.
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Old 05-20-2003, 01:02 AM
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I only have analyzed one timing cover and pump so thats what I thought might be the problem.
I run really cool plugs in my motor and it definately likes 190 degree water, so I know what you mean for qualifying.
I run a 7 blade fan, have always wanted to try the 4 blader, I also have no shroud and I have the front end blocked off completely so no mud can block the air flow through the radiator, plus I have 58 nights on this radiator and all the fins are perfectly straight, Knock on wood
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Old 05-21-2003, 04:04 AM
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heres the deal I pressed into the head
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Old 05-21-2003, 04:05 AM
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heres the t where it connects to the other head
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Old 05-21-2003, 04:07 AM
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heres my radiator, if your wondering what a dual pass looks like.
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Old 05-21-2003, 04:08 AM
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I run a piece of plastic to keep the crap from the fan out of the air cleaner, simple but it works
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Old 05-21-2003, 04:10 AM
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I dont run any holes in my front end, this keeps the rad free from mud and bent fins.
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Old 05-21-2003, 04:12 AM
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whoaa wrong picture that wouldnt stop much would it, HA HA HA
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Old 05-22-2003, 07:15 PM
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Sanborn: Do I need to punch a hole in the head gasket in the front of the block? The 1008 head gasket only has hole on one end. Do both front 1" holes need to be open on the front? Also I noticed you have water lines on your timeing cover. would this work in place of running the water lines on the upper water neck?Thanks Dirt Dodge...
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Originally posted by sanborn
I have found over many years of racing that don't want to restrict water flow through the engine. NO RESTRICTORS!!! And, I've found it best to turn the water pump no more than 6000 Pump RPM. So, if you turn your engine 6000 RPM, use a 1 to 1 pulley ratio. If you turn your engine 8000RPM, use a 25% reduction pulley set. If you turn 9000 RPM, use a 33% reduction pulley set.

When you are at maximum RPM, you are generating maximum heat-that's not the time you want your pump to quit working.

Let's review the water flow path through the block and cylinder heads:
Water is pumped into the 1" diameter hole in the front of the block. From here the straightest shot is to the back of the block and the 1" diameter hole there. That's where most of it goes. Sure, some of it goes down to the bottom of the block and goes up into the heads in the row of holes in the bottom of the deck of the block. But most goes to the large hole in the back. This is exactly what you don't want to occur.!!!!!! Block off that 1" hole in the back of the block, force the water down in the block and force it to come up into the heads through the holes in the bottom of the block deck. This maximizes the water flow around the exhaust valves(where most of your heat is). You want to keep your exhaust valve seats as cool as possible.
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Old 05-22-2003, 07:39 PM
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I think I understand the first part of your question- not sure if I understand the second part.

The two large holes at the top of the block deck should be closed. If left open on the front that would allow water from the pump to enter the block and immediately go up into the head and out the intake manifold. This you don't want to do. You want to force the water down into the block and flow up into the head around the exhaust valves.

For the second part, the fittings on the timing cover connect to a #10 fitting in the center of the block just behind the center head stud. The purpose is to get cool water to the hottest part of the head-which is between the two center exhaust valves.

Did this answer your question? If not, ask it another way-Sometimes this old bald head is too dense!!
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Old 05-22-2003, 07:48 PM
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so what your doing is closing off the two 1" holes that the head gasket does'nt cover, one in front and one in the back.
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I think I understand the first part of your question- not sure if I understand the second part.

The two large holes at the top of the block deck should be closed. If left open on the front that would allow water from the pump to enter the block and immediately go up into the head and out the intake manifold. This you don't want to do. You want to force the water down into the block and flow up into the head around the exhaust valves.

For the second part, the fittings on the timing cover connect to a #10 fitting in the center of the block just behind the center head stud. The purpose is to get cool water to the hottest part of the head-which is between the two center exhaust valves.

Did this answer your question? If not, ask it another way-Sometimes this old bald head is too dense!!
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Old 05-22-2003, 08:15 PM
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Yes, that is correct. Except I do drill a 1/8" hole in the freeze plug that I use in the rear of the block-but the 1/8" hole is to eliminate any possibility of an air pocket.
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Old 05-26-2003, 10:20 AM
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Great stuff Sanborn! Temp consistency has proven to be difficult and effective…with that in mind have you played any with reverse cooling? I like the idea of cooling the heads first… pushing heat down the block…especially on short stroke/long rod motors…

In general…on a handful of motors I’ve had some “crossed fingers” success with relatively mild (1.5 hp/ci) motors in switching impellers (direction) and turning the pump “backwards”, but the only confidant thing I have to say it was a success because overheating wasn’t a problem….lol…and of course care goes into pump speed.
Only one particular motor hinted to any significant improvement….a 383 drag motor (1.88 RR) with KB’s that kept sticking pistons with a shot out of the blue bottle…last ditch before an entirely new combination was reverse cooling as mentioned above…and the problem went away (don’t even ask “why didn’t you do this or that different?” lol…long story and the whole thing was kind of an experiment)
Above 1.5hp/ci…or anytime it’s feasible we plumb the motor similar to your setup for consistent temps and push water down from the heads first…and if we can get into water between the mated exhaust ports and pull from there we’re really happy even if it’s a small amount.
I don’t necessarily think it “makes” more power…maybe loses less in some areas…maybe better ring bite further down the bore…but in my view all motors are prone to detonate in some scenarios…if not outside the power stroke….then inconsistent burn within the ignition lead through power stroke burn “time”…as many of the reverse cooled and improved cooled motors seem to like a few less degrees lead…indicating in
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  #30  
Old 05-28-2003, 09:01 PM
340king 340king is offline
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Join Date: Oct 1999
Location: Fort Pierre, SD
Age: 61
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Biggrin Great Ideas

I am very greatful of having some experienced racers on this board. In the past I have routed the water out of the intake in the same fashion as shown. Only, I sent it directly to the radiator. I placed it part way down the tank on the cross flow radiator.

One thing that must be addressed is the hidden benefit that a good flowing water pump gives. That is increased block pressure. This helps us in two areas. One is minimal in balancing the pressures ever so slightly between the combustion chamber and the coolant chamber(block stiffening). The other more beneficial area is in reducing the possibility of hot spot boiling. Like Cageman alluded to pressure increases the boiling point of the liquid. The better the flow the more pressure the dynamic situation has in the block.

Some things about steam. The latent heat is the heat needed to change it from one state to another. In boiling, it is the latent heat of vaporization that is required to convert 212° water to 212° steam. Conversely, the latent heat of fusion reverses the process and forms water out of steam vapor. On a mass basis, steam has much more potential energy heat wise than water. That is due to the latent heat. I hope this clears that up. The other issue with steam was mentioned. It takes up so much more space. In addition to that, it takes way more space to cool it down also.

One final observation. 340's run cooler than similarly prepped 318's and 360's. I don't have clue why, but they seem to in the applications I have trie
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