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Formerly known as 89 steeda
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I was just wondering if anyone has tried a reverse flow cooling system on a 5.0-5.8. I seen in a new mag where someone did a 351w with cleveland heads with this set up ,but did not go into details on how he did it. Do you think it would be worth the effort? I would like to hear some details if somebody tried this.
 

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Nope, definatly NOT worth it. The cooling design as stock is perfect, water enters the block (cold) and pulls heat from an area that requires little to no heat, the main webbing of the engine. Then proceeds now that it is warming to the hottest point in the engine, the heads and combustion chamber of the engine. Ideal combustion chamber temperatures for optimum performance is about 210 degrees. There is sufficient delta between the water temperature and the combustion chamber area that water continues to remove heat. The HOT water then exits the engine to get cooled.

Pushing water in revers, would cause imeadiate access cylinders to have super cold combustion chambers, and the remote cylinders to have more uniform and or hot combustion chambers. Then your trying to counter the natural flow of HOT water, by pushing it down into the block... (hot likes to rise naturally) and you add all that heat into the main webbing of the block, crank, oil etc... before extracting it from the engine.
 

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Formerly known as 89 steeda
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Thanks for the input, you make good points. But didnt GM do this on the LT1 or whatever they are called 350's in the Camaro's and SS caprice's from the late 90's ?I thought they had cam driven water pumps that flowed from top to bottom.?.
 

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Lots of small block Chebbie race engines run a forced coolant flow to the head. They had to combat that siamesed exhaust port and superheating the head right there. Sooo they sacraficed performance for survivability. As the Fuel injected engines got leaner and more efficient the exhaust temperatures continued to rise.

Dont know how old and how much ancient history of Chebby you know but carberated Chebbies were always tunned pig rich. Blind you all the time. Combustion temps (EGT) were kept in the 800 degree range, higher end emissions and the EFI system well 1300 degrees is the norm. Lots O cracked iron heads. SO I believe they used the racer trick of super cooling the head... I know about the race engines doing it, I do not know that it was ever done on a stock engine.
 

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Yes the Chevy LT1 has reverse flow cooling, not sure about the LS1.

Some local friends swear by it and can run 12 to 13 to 1 compression on pump gas in LT1 motors according to them.

Not sure how you could pull this off on a small block ford, maybe plumb in some external lines to the rear water ports and do the same to the front then have return lines going from the timing cover to the upper radiator. I think a remote mount water pump would be easiest. the chamber would be a lot cooler of course but that is where the extra compression or boost would come in....

It would be nice to have the time or money to play all the "WHAT IFs"...surely someone has done this and can offer input?
 

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I think I am going to give this a rip. I plan to use an electric pump to push the coolant into the front of the heads, keep the head gaskets positioned like stock, and have it exit the block where it would normally enter it. My only concern is how to "burp" the system to get the air bubbles out. I was thinking of drilling and tapping the back of the intake where the coolant opening is on the heads and put a fitting in there to let the air collect so that I can let it escape or top off the fluid. Any suggestions? Thanks, Nick
 

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Reverse flow cooling is the way to go. First of all, it keeps the intake alot cooler, in GM cars, coolant never touches the intake manifold. Eliminates alot of problems there. Second it cools the intake side of the heads allowing for a colder intake charge but the cylinder walls are hotter which help effeciency. With reverse flow cooling, you can run 10.5 plus on 87 octane. Forth, in the design it prevents the shock of cold water when the t-stat opens. There are more reasons also. The LS1 runs reverse cooling, gets good gas milege, is really reliable, and makes more power than other makes such a Ford and Chryslers.
 

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The LS1s run reverse cooling to? I knew the LT1s did, but I was unsure about the LS1s. I might actually start out with the stock setup on my car and then change over at a later time to the reverse cooling. This way I'd save a couple of bucks intially to get the car running and I could compare and contrast my version and give some feedback. My biggest concern is "burping" the system to get the air pockets out.
 

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Yep the LS1's are indeed reverse flow as were the later LT1's...

If it was so good, tell me why the LS1 has so many ring problems, piston problems, and many other bottom end problems that may or may not be related to this? Hell, GM even issued a TSB/Recall for piston slap and other noises...Hmmmm could this be caused by reverse cooling... how many Ls1's are at your local track with well over 100k miles on them making back to back passes and then driving them home with no problems?

I like the LS1 and I agree its fast as hell, but it just doesnt have the reliability that my ford does and never will.
 

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For what it's worth, we just put into operation a 351w in a sprint car with normal cooling system configuration and no fan.
Using only a restrictor in place of a thermostat, the engine runs 180* and actually not hot enough for our use.
The Chev guys have all kinds of plumbing changes and we still make more power than they do under the rules.
Unless a specific engine design is known to benifit from these changes there is no use waisting time and money just to do it unless you like doing things to see what the results might be.
 

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If you trace the high combustion temperature, more power theories through this site, it originated from a guy who has probably read one page out of a thermodynamics textbook and didn’t comprehend one paragraph of the page that he read. The actual equation that he is most likely referring to addresses the differential between the maximum combustion and outlet temperatures.

Even if you haven’t attained an engineering degree, common sense should easily get you through this one. First, consider that the actual combustion temperature is near 2500 degrees F, or 1650 degrees Kelvin. Consider next, that the water temperature is between 180 degrees and 210 degrees (between 355k and 371 K) a difference of 16 degrees Kelvin.

With regard to the combustion process, the amount of energy developed is the difference in energy resulting from the molecular bonding of the resulting carbon dioxide and water, and the molecular splitting of hydrocarbon and oxygen. The energy needed to split the original structures in comparison to the recombination energy is in the area of parts per million. The splitting energy is the only one of the two effected by the initial temperature.

With regard to heat lost after combustion, given that the difference in sink temperatures varies by, at most 16 degrees, that the delta temperature is over 2000 degrees, and that the combustion process occurs in a fraction of one time constant of thermal conduction, the resulting difference in the ending temperature of combustion is essentially zero.

So then, what is the optimum temperature with regard to the development of horsepower? The easiest way to resolve this question is by looking at what was done on the 1960s muscle cars. Each and every engine was designed to run at essentially the same temperature, 180 degrees. So how did these groups of PHD level engineers come to the conclusion that this was the correct number?

Well, they knew exactly the same thing that I know, that the amount of oxygen and hydrocarbons that can be passed through the intake valve determines the volumetric efficiency, thus the horsepower output of an engine. The colder the air charge, the more volume that could be passed though. They also knew that they needed to reliably vaporize the volatile liquids (namely condensed water) that would contaminate the oil. 180 degrees was the temperature chosen in order to accomplish both.

Have the engineers changed their minds? No, the new engines run at a higher temperature for one simple reason, emmission output. The hotter the input charge, the higher the vaporization of the hydricarbons (heated intake manifold)and the more hydrocarbon-oxygen resultants that are converted to CO2 and H2O, rather than CO and HC.

The bottom line: The reverse flow, if you can accomplish it with even bank to bank flow rates is a great idea.

BTW, late ‘70s and early 80s chevrolets ran leaner mixtures than the LT1, not richer mixtures in order to raise the combustion temperatures to much higher levels and CO to lower levels. This was due to the fact that Nox emmissions were not at the time a significant part of the unwanted byproducts.
 

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I think there are more than a couple of reasons why 180-195 is a common coolant temp...............

One is cooling system materials. Rubber hoses and the coolant itself to safely operate at, say 300*F, would be some pretty expensive stuff, and would it have a much shorter life expectancy??

Also, metallurgically speaking, some metals don't like to get too much hotter than they are currently operating at. Look at the 882 casting chevy heads and how they would crack if you even think the engine is beginning to overheat. Just no room for error, there.
 

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Building an engine that would run at 300 degrees is most likely entirely possible. Long skirt, higher clearance pistons, a chemically hardened in lieu of heat treated set of rings, and synthetic oil would probably cover 90% of the design changes. The difference in component expansion between –40F and 300F isn’t drastically different than that of –40F and 210F.

There are plenty of materials that could be used to replace the vulcanized rubber utilized in radiator hoses; some of the Teflon based materials are good to more than 700 degrees F and relatively inexpensive. No one makes a production engine that runs at 300 F for the same reason that no one makes three sleeved shirts. It’s not that it’s a technological impossibility, it’s because there’s simply no justifiable reason for it.

The 882 casting process was defective and most had hairline cracks from the factory. It was the thermal cycling that finished them off, not the absolute temperature. The 414s with 2.02 intakes were the heads that were temperature sensitive, but even they were still good to at least 240. Moreover, you would end up with no less margin running the 882 or 414 heads at 210 instead of 180 because of the simple fact that cooling efficiency increases with engine temperature and the maximum temperature is set by the cooling capacity of the radiator and fan, not by the thermostat
 

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Damn, this turned into a discussion for engineers and thermal dynamic PHD's!

So tell me one thing, if it worked so well, why don't everyone use it (reverse flow cooling)?? fords 32V mod motor is very advanced and they didn't see reason to use reverse cooling...
 

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Can someone take this a step further and bring in the special cooling mediums such as the EVANS sytem and how it increases engine power if at all, from the change in cooling temps during operation? Would some engine designs have problems operating at these levels before some type of failure takes place due to the higher temps?
 

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ssk; There are a number of reasons for not using the design, but piston slap and ring problems aren't part of the reason. Chevrolet decided to use short-skirted pistons on the LT1 design. Ford could have decided to stay with what they had for marketing purposes (following your competitor is never a good marketing plan) or it could have just been NIH.

There are three important qualities of coolant. The first is surface tension, the second is specific heat, and the third is boiling point

Surface tension describes the molecular attraction of molecules within a liquid to each other; the high surface tension of water is what causes it to form in the shape of a sphere when it drops. This attraction precludes the liquid from forming an intimate contact, necessary for efficient heat transfer, with other surfaces.

Specific heat describes the amount of heat needed to raise a specific amount of liquid from one temperature to another. In other words, if one liquid has a Specific heat of .5 and another has a Specific heat of 1, it will take twice as long to heat the second liquid up, given the same heat source is used in both cases.

Boiling point is obvious.


The Evans coolant has a much lower specific heat than water. This isn’t as big of a deal that everyone here on this site makes of it with their special water/antifreeze mixtures. A lower specific heat requires that the coolant is cycled at a faster rate in order to keep it from saturating. Otherwise, it makes absolutely no difference in cooling.

The surface tension is what is effected with water wetter, is very low in the Evans coolant and is the main benefit of the technology. You may, however, be able to accomplish the same thing with water wetter. Also note that this is what is given up when running the coral-preferred low antifreeze mix.

The boiling point is much higher, but who cares? 50% eg/water boils at 265F @ 15psi. At that point, the friction between your now zero clearance pistons and their corresponding cylinder walls has probably welded the two together anyway.

NGN, I think that I can put together a control system that will allow you to do this without a thermostat.
If you’re interested, e-mail me @ the dccontrol site,
 

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You have read a lot of material, and probably graduated with honors...


But your textbook information is NOT a repeat of reallity.

I've started about 6 differnt rebuttles, but deleated them knowing the ensuing "discussion" would not change a thing. A certain group will take your book driven information, your revrence for "engineer ancestors" and go off believeing the gosple has been spoken. Others, will continue to test, and come to the conclusion that lots of the supposed CORRAL "spew" has been proven in street and strip cars alike... not to mention a few other venues of automotive performance.

265 will not weld piston to cylinder. I wouldn't recomend anyone TRY to run there, but beyond pushing that hot an engine into a detonation situation AND blowing the head gaskets, there are numerous NASCAR as well as assorted Drag engines that have hit and exceeded 265 liquid engine temps and have continued to perform.

For a street variant car 240 is about as high as anyone dare push an envelope before catostrophic failures can be expected... head gasket typically the first thing to go.
 
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Dave Storlien used a pump from Grainger catalog for his SBF entry(Engine Masters) he has also street driven a SBC 'vette with such reverse cooling
arrangement around the Twin Cities for years...not book theory. Don't give
a riff if not believed...I could post Dave's number..he'll tell you what is
involved, you pay the long distance.
 

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.the real problem is STEAM.....
or air pockets...

the heat just has to be balanced.......
 

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Kim;
Actually, I was being facetious, but in reality, it would depend on the type of piston utilized, the initial clearance between the piston and cylinder, the rpm of the engine when the friction on the piston overcame the rotational momentum of the motor and the linear momentum of the car that it was in, and a number of other things. Perhaps my tongue in cheek comment was a bit too subtle for you to pick up, but I would think that most everyone else in the thread got it.

I apologize if introducing scientific reasoning into this discussion has offended you, but I would tend to believe that virtually everyone who has viewed this thread has attained some knowledge of the subject matter.

With regard to your somehow coming to the conclusion that my level of education would render my comments invalid, keep in mind that the engineering team designing Ford racing motors isn’t comprised of a group of rednecks who are constantly shouting lookie thahr! Engineering IS reality, a moron’s conclusion drawn from an observation isn’t.

Would you like to debate any of the points that I’ve made ?
 
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