CarolinaCamaro

I researched some postings but there doesn't seem to be as much info on this as I was hoping. I was hoping if someone could corroborate, elaborate, or discredit the following: (sorry it is long and multiple related postings)

"Guys,

If you look at the coolant flow through an LS series block, it doesn't appear to be very difficult at all to convert. I do

know that it has been done and I will be converting Darton sleeved 427 when it goes back into my SS. FWIW, I always drill

and tap the front and rear coolant bleed holes on any max effort deal I do. I run -6 lines from all four corners of the

heads to the top of the radidator in the stock location. This was suggested to me by Kurt Urban a couple of years ago.

Since that time, I have successfully run 12:1 and above with 93 octane pump gas (with good chambers...) I do this mod on

all nitrous and F/I builds and some NA builds if the owner is up for it.

Getting back to the reverse cooling issue, taking a quick look at the passages in the block and head, if we feed the top

hole on the block first and make the lower hole the return, I see no issues with bleeding the system since the fatory

coolant bleed holes are the highest point in the cooling system (assuming an F-Body setup.) This would be a simple setup

using an external WP with Meziere's AN adapters.

I may not be 100% correct in all my assumptions but I am confident enough that I will be doing this on my own build.

Shane

************************************
I posted this on the 944 Hybrids forum where I'm documenting the build....

"I am only looking to do a mod to the LS water pump and remove the thermostat. On the last V8 swap I did to a 2.8l S-10,

all I did was remove the T-stat and did not change to a larger radiator. All my overheating issues went away. In the

winter, I just reinstalled the T-stat and the heater blew nice n hot and engine never overheated. My theory is the stock

Porsche 944 NA radiator with the T-stat removed would be the best cooling set-up and obviously the easiest. The inner port

hole between the heater ports on the LS1 pump can be blocked off. I have read elswhere that a 1/2" hole is drilled in a

freeze plug and installed. I also see that the 160deg T-stats have 4 small holes drilled in that block-off plate. The only

reason I can see why GM put that small rear block-off plate(spring loaded) was in case the radiator (even heater core) were

to be clogged, the coolant would just recirculate within the block. Looking at the Truck Pump, the inner port hole could be

enirely blocked off with an epoxy'ed freeze plug or the stock T-stat could simply have the upper piston drilled/removed and

the heater would function normally and the water velocity would remain constant and increase with RPMs".

"I removed the back cover from the truck WP to double check the flow route of this pump which should be exactly the same as

all the LS pump routings. From what I see, if that inner port hole is blocked off completely and the T-stat removed the

coolant velocity would be higher going to the top radiator and cool much better"

Looking at the truck pump veins, I don't see why the serpentine/pully can't just be reversed and the same mod done to the

port hole and the water would flow backwards for head to block cooling (reverse).

**************************************
I am new to the LS world a short time ago I was mistakenly under the impression that like the LT engines the LS were

"reverse cooled". Several years ago I ran some Evans Cooling products in a Ford engine with very good results. Since at

that time I wasn't working on any GM stuff I got the full story when talking to the Evans guys.

Anyway when we set out to build our first LSX Block Nitrous engine I made a slight mistake. The engine would use a remote

water pump so we welded AN bungs to the motor plate. The mistake that I made on the initial engine is that I reverse cooled

it by hooking the water lines up backwards. That engine (in that configuration) made the most horsepower that we ever had.

We never had a problem with cooling or steam. This was a drag race engine with little time to heat up.

Since my error was pointed out we have run the lines the proper way. One of the things on my list to check on the dyno is

to do back to back pulls with the lines hooked up both ways.

I should be able to get back to the dyno in about a month and will give it a try at that time.

I had some conversations with a thermal engineer regarding the flow through the engine. The gentleman that I discussed this

is very in the know and currently works in the business. The mapping and probing that is done on water flow models is

unreal. He felt that I got lucky because of the short run times. He felt that the gasket restrictions would need to be

studied to provide the correct amount of coolant for enough time to absorb heat from the heads and block.

Hopefully I can try it again and let you guys know what I find.

Robin

********************************

One problem with the small block Chevy, and now I believe the LS*, is that with both heads flowing into a single port, then

into a hose back to the rad, each head does not flow at the same time. This was something Smokey Yunick investigated. What

happens is that as the coolant heats up and begins to flow, one side(head) will heat up faster ie. hotter, with more

pressure. This greater pressure makes only the hotter side flow because of the greater pressure. Then, as the hotter side

flows, it cools down enough, aqs the non flowing side heats up. There is then a transition of flow. In the end what happens

is an alternating flow, resulting in an inefficient system, and hotter heads, and less compression.

What "Smokey" did was drill holes into the ends of the heads edging towards the exhuast side ( hottest ) . Tapped and

installed piped fittings with hoses and a Y juction to a main rad return hose. This allowed the heads to flow more

effiently(from the front of head) and to flow simultaneously, resulting in more stable head temps.

It would seem that the LS1 heads are ready made for this mod, with the casting plugs in the exact optimum area.

"Smokey Yunick" for those that don't know was yester years David Vizard in the racing/performance genre. He has many

patents including the extended tip spark plugs we all enjoy. When I read something of his, I take it as gospel. Though some

new technology and metalurgy has changed from his days. He tried to get GM to use a reverse flow setup for many years.

Your thoughts are appreciated...

Art

CarolinaCamaro

any comments? jeesh this forum ain't what it used to be...

Old SStroker

You Sir, are a master of understatement.

Jon

robsquikz28

iTrader: (246)

never gonna happen

RedVertTA

iTrader: (9)

It already has.

Irish350

iTrader: (14)

wish i could provide some input, but i havent really got any to provide. I seem to remember that being one of the 'big deals' with lt1 vs sbc technology, so i could see the logic behind looking further into it.

gametech

iTrader: (1)

So arguably the best group of engineers in the world tried this and after a few years of research decided it was a stupid idea. As it turns out, square wheels really aren't better than round ones.

RedVertTA

iTrader: (9)

That's not what happened, they didn't incorporate it into the ls1 because of patent and legal issues. There are people on this site who have run reverse flow on their lsx engines and reported gains and less predetonation.

gametech

iTrader: (1)

Since they already did it on the LT1 with no patent or legal problems, exactly what makes you think they have those problems with the LS1? I am under the impression that reverse flowing the coolant showed no legitimate gains, but does cause air pocket and hot spot issues.

RedVertTA

iTrader: (9)

This discussion already came up on another thread but it has been confirmed that GM did not incorporate reverse flow cooling due to patent issues. I'm not sure why this only came into play after the switch to the ls1. Strange but it makes sense. As I stated before many site members have run reverse flow without problems and reported gains, nothing magical but gains nonetheless. That being considered there doesn't seem to be anything negative about reverse flow cooling that would have caused GM to scrap the idea.

AaronSRT8

That's the dumbest thing I've ever heard.

Update, GM engines can no longer use valve covers because those are patented.

RedVertTA

iTrader: (9)

Don't get me wrong I agree, I can't understand how anyone could patent a coolant flow orientation method but that's what has been said.

We know based on the comments of members on this site who have run reverse flow that there are no apparent negative effects and that there are gains to be had so we can assume that GM did not scrap the idea because of performance problems.

So what could have been the reason? Any guesses?

On a side note your valve cover example does not apply because after 20 years patented technology becomes public domain and the valve cover patent (if there ever were such a thing) would have been around for longer than that.

trik396

iTrader: (4)

Not so dumb really... GM was sued for reverse flow cooling design. I believe it was Evans who patented this design and GM did not have an agreement to incorporate it into the LT1. Last I heard the lawsuit was still pending. My guess is GM stopped using it because their lawyers told them they were going to lose the case. Lick your wounds and walk away.

What makes you think you can steal a design and get away with it especially on such a large scale? Don't you think it would have been easier to contract with Evans to use their design, pay them their royalties, and be done?
read this...http://money.cnn.com/magazines/fsb/f...3431/index.htm

gluon

Ceramic coating the pistons, chambers, valves, and exhaust ports helps as well. Water injection really helps, who says its just for forced induction? I am sure 13:1 or even 14:1 could be doable with water injection.

RedVertTA

iTrader: (9)

?????

What does this have to do with this thread?

trik396

iTrader: (4)

Reverse flow cooling is a way to run more compression with pump gas. Everything gluon stated will also help.

blacksi

iTrader: (3)

I agree it sounds rediculous, but you would be surprised what patents can keep you from doing.

Ex. my company sells a device that uses an internal spring to support the weight of the device as it moves. Our competitors must use an external spring to support theirs due to a patent we have.

Black FormulaLs1

iTrader: (10)

valvecovers bwaahaaahaaaaa nice!!!

venom99

iTrader: (32)

back on topic hear how would you go about converting the head

white2001s10

iTrader: (4)

I would not trust simply reversing the direction of pulley rotation to achieve functional reverse-flow.

I have run without a tstat, and with the bypass port blocked, and cooling capacity is indeed increased significantly.

The factory cooling system design of the LS1 is initially at a disadvantage due to the input and output ports on the block being right next to each other. At least some significant percentage of coolant flow will be taking the path of least resistance. The over-sized bypass port only adds to this disadvantage.

I think if I were to reverse-flow an LS1 I would modify the block more-so than the heads. I think the coolant ports are poorly placed for cooling in either direction.