From what I under stand is it converts very easy and was desighned to be ran as Rev-cooled but the Law suit changed things.

Then again it may be a rumor and nothing more.

There is some very good reading here

 

Is there somewhere that shows a diagram of which way the water normally flows in and out of the factory water pump and which way it flows out of the Block as the water pump pulley normally rotates CCW?

I want to know if my heater in my 5.3l swapped Porsche will still function if I remove the T-stat altogether from the Vette pump and plumb the heater exit ports as normal...I machined adapters to set the Vette water pump out to match the Truck accessories.
I also wanted to confirm if the large heater port/snout is the return or feed to the heater core?
Thanks...

 

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 find it hard to believe that someone could place a patent on which way coolent flows thru a hose. How a manufacturer chooses to transfer heat from a component should be up to the engineer who designs it.

I heard that reverse cooling is for hot spots on heads that have staggared exaust ports. On the Lt1 motor the exaust valves are next to one another creating hot spots. on Ls1 motor the exaust valves are not staggered.

 

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 was actually going to try reversing the coolant when I swap over to the small radiator and remote mount pump, just to see if it would work.

xtracajun, I was also told that when I have my motor apart, to tap the holes in the heads where the factory crossover tube is located, both front and back, and run a small line to a shower head type block, then run a line from that to the radiator. Not sure if that's the same thing you're talking about or not, but if it is, then it's probably for the same reason.

 

I made myself a flow "schematic" to try to understand how LS1 cooling works...

(the square/circle symbols indicate the coolant ports in front of the block)

Note:
The BP is not necessarily open when the TS is closed...
Old Geezer section cut his pump and observed that the BP valve is still seated when the TS is closed.

I made some crude measurements on the bypass valve area and spring rate, and I approximately determined:
- with TS fully closed, BP valve requires at least 5 psi pressure difference across it for it to open;
- with TS fully opened, BP valve requires at lest 10 psi pressure difference across it for it to open.

 

i.e. if you tried to reverse flow, the stock TS/BP would not function correctly (both the TS and BP)...

The TS would be on the wrong side, and the BP would be pushed shut all the time.

 

Being 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

 

New here! Just ran into this post great thread.

Anyway, back in the day I raced a 94 LT1 and was impressed by the reverse cooling. Testing the idea I plumbed a cooling line to the center of the heads on my 12.1 408 bb and made a big diff on the street!

Evans -according to a cnnmoney.com story was able to solve the reverse flow cooling problems by running a simple cross over pipe in the back of the heads at its highest locations attached with 2 "bango" fittings. This pin hole fitting is the key to success in reverse flow cooling on LT-1's and the mystery he solved in 89 and presented to GM?? The LT-1 was born...

Ive been converting my 377 to LT-1 style cooling and should be finished in a month or so. I can only assume the same idea should apply LS engines.

 

Robin,

Any feedback yet on the coolant direction relationship to power?

 

Wow, this thread has been running for 5 years, now back from the dead.