Flow Cooler Opinions Needed.

[MrMarty51]

I’m getting ready to get the 2000 K3500 into the garage to install the new cooling system uprated components.
In @Will L. s thread, a pic of the pump and the backing plate shows that the ports on one side are not matched.
Just looking for ideas and opinions if it would be a good idea to use the die grinder and remove minimal material until the ports match between the plate and the pump.

 

[Twisted Steel Performance]

Couldn't hurt, will it help, maybe .05%....

 

[Wreckinball67]

I would do it. Please report back with your progress and a few photos would be great.

 

[MrMarty51]

I sure will.
Step son is now in the garage scalping on his 80% lower receiver for his 1911 pistol kit. When he gets done I’ll have him help me to get the garage door opened, get the truck run in and get to work on the cooling system mods.

Thats the 1911 jig and frame with the scalping process just beginning.

 

[Will L.]

When the 6.2 had no heating problems is was like 130hp /220 torque engine. We crank it up 210hp/440 torque and it pumps more heat. Roughly 30% of the fuel burned becomes power- so 70% is heat out the radiator via water pump.

So when the 4 bolt v belt pump worked fine in the square body huge radiator getting tons of air- all was fine.
More aerodynamic, more power both make it worse .

Serpentine belt reversed direction and caused flow issues they didn’t expect.
The 4 bolt waterpump was replaced with 4 bolt high output. That still had problems.

The oil company I worked at had the huge fleet of pickups, and since we were already doing longevity testing with different oils for gm, and we were having problems with trucks overheating- one of the owners of the oil company simply refused to give back 4 dozen test trucks because our fleet trucks were dying and couldn’t get parts. He also refused to give them the final findings of the oil testing which they were hurting for. When the honcho of GM came here and met the 2 owners of the oil company- they released everything. But it was a ploy to get them to come look at the problem we were having in person.

It was from that we became their testing lab for overheating. They really thought it was a few cities that had dealerships in Agreement just ramping up costs to GM over these engines. GM corporate really did not understand the overheating issues that they had in the south west.

We did tons of testing and the end result was gm made the spin on. Why spin on-2 reasons.
Faster assembling even though cost to produce is more- so not a big net gain.
The problem is overheating trucks with 4 bolt pump would come in and get new pump under warranty.
But because they didn’t want to do recall for legal reasons, and so tracking via vin number wasn’t being done like normal. They only expected to have 10,000 or so older trucks come get it. But dealerships saw income in the 90’s when they were dieing and not getting much work. So they turned in every truck for everything that corporate would pay for, so trucks that already had the new HO 4 bolt would have it replaced with another HO waterpump. As you all might notice- you can’t see the HO casting inplace with everything in place. So they would have to pay labor to see if it was done, and as others that worked in dealerships will attest- usually the mechanic gets screwed. So the mechanic would say it was overheating and improper flow without even checking it to make sure he got paid. So corporate wanted a clear cut way to id newest pump from oldest. Spin on did 2 birds one stone trick.
This is straight from the GM engineers I worked with btw- not guessing. I don’t give a flying F what bill heath said. The guy that was the retired engineer that typed up that letter for him- I dealt with the engineers that did the redesign personally.
Thats how I got all those free 6.5 engines.

Balanced waterpump flow fixed the issue. But understand- it was key having the restriction fitting and second heater hose rerouted.

People say 100 gpm and 130 gpm, but really it is 97 and 127. The 4 bolt HO moves as much water as the spin on-127. But it sends most of the water to the driver-side of the engine. Hence all the #8 cylinders cracking not #7 which had same nodule some folks blamed and same ring gap difference. And the issue is amplified by the centermount turbo in vans/hummers because of the up pipe. But still n/a had the issue- for instance my 95 n/a hummer (along with many others) so it is easy to shoe it isn’t the turbo causing it. The serpentine belt reversed direction. Hmmwvs were running the worst airflow over radiator- weighed 15,000 lbs beat in the deserts and handled it for 2 reasons: full lockup fan clutch helped, but mainly v belt still used. When the hmmwvs started running serpentine belt- that is when they started cracking blocks. Look it up- they did one of their 200 page reports that came out later and it referenced the lawsuit that caused AM General to due the formation of GEP forced into GM by a judge. GM wanted to walk away 100% from 6.5 but couldn’t by court order. Then had to release the info to AM General snd the judge- but restricted it from public view so competitors couldn’t learn trade secrets. But one of the AM General engineers that knew what happened was one of the guys I met when doing the hmmwv hood scoop testing. It was clearly known but GM learned its leason from the Ivey memo and squashed all recorded info of known problems.

Ok. Back to what counts now. 2 things

1. You have to move enough water through the block and heads. Roughly 60 gpm per bank is enough. More is fine, until so much happens that you get aeration and cavitation issues.

2. If 1 bank of cylinders gets so much water that the cylinders and precups are kept a lot colder than the other bank- you will simply will have an unbalance of power. Think how many guys here want 195f all the time for best mpg and shoot down my beloved 180f for that reason. They also get another 2-3% more power from 195f than if it is 180f. So now think cold cylinder bank vs hot cylinder bank. It is easily understood by anyone that ever had a set of injectors that were unbalanced get adjusted so they are all the same.
You don’t see the power loss until it is fixed.

So you could run a MEGA PUMP that does 300 gpm and get all the cooling you need and never overheat from lack of water flow. But imagine 200 going through 1 bank and 100 through the other. Is that unbalance causing power difference? Have to test it to see.

Now, if a person does other upgrades to an engine where overheating gets mitigated - they could maybe run the original 4 bolt 97 gpm and not have problems just like the imaginary mega pump. Is it peak performance? Who knows.
What I do know is this:
GM lost boat loads of money and redesigned multiple water pumps before getting it right. I cut the side out of a couple blocks and mounted mr5000 bulletproof Lexan (yes copying the interior of those walls exactly) as the new walls to watch the eddy currents and how it messed with cylinder cooling doing different changes. GM actually had a full Lexan block made that bolted together before it was all over with to test the different rear head port options that all failed and caused more problems than they solved.

Think about airflow through a head. Does opening all the ports all the way biggest the best way to go? Why raise the roof and lower the floor isn’t the best thing? Because after TONS AND TONS of testing and learning we know the flow is a crucial factor.

Most here know the rear head hose kits are a mistake and knew it well before I joined here. I had to point out on hummer forum didn’t they think maybe GM engineers were smart enough to try a simple and low cost fix? Add a couple fittings and little heater hose rather than redesign a water pump time after time after time? Yeah....

So who here REALLY THINKS GM engineers are so stupid they didn’t try doubling the waterpump output to the 195 gpm range.

Thank goodness flow kooler figured out to use the same impeller design used when the hoover dam was made 100 years ago. Because surely the engineers at GM aren’t good enough to have thought of that ever like the replacement cartridge pumps they did in the 40’s. Wait, they did. And they abandoned it? Cavitation? Whats that? Eddy currents? Who is he?

I called flow kooler way back. They didn’t know crap about the 6.5. They are marketing a pump as the best pump for every engine ever and using more flow and (pay attention here) more head pressure as how it is better. They had their ‘engineer’ (i hit him with some tech questions and he didn’t know boyles law. Didn’t know the difference between galvanic corrosion, electrolysis, and cavitation corrosion. Couldn’t EVER ( I bet to this day) have gpm number of the pump total or in closed system. They push head pressure as a great thing but he didn’t know difference of impeller vs positive displacement pump. He was as confused as the people thinking the bigger waterpump of the spin on or HO pump would push out freeze plugs by creating more pressure in a heat induced pressure system.

Is it a horrible mistake to try running these pumps? Idk. But I can’t afford being a lab rat for them at the cost of ruining an engine.

Should someone start porting their water pump or backing plate to experiment if that fixes issues or causes new ones? If you don’t mind learning by engine destruction- sure go ahead and try. I sure can’t afford new engines. All the different things we tried back in the 90’s- sure as hell destroyed engines learning what not to do.

I am not against testing things, and areas that have know issues even today like the steam pockets- yeah probably worth trying so long as you keep flow equal throughout the system. Like welding the head ports completely shut- interesting idea but would be dumb to only do one side.

I would just warn do it with a beater engine that you can push crazy hard to gets results fast. Load that engine hard as heck, run it on oil not getting cooled and stess that engine hard as you can so you can see the difference immediately. Obviously need to do hard test with regular pump and no other alterations to see one change made is responsible for improvement or devastation.
Then when you do it on your engine you care about- you know it works and wont be the cause of cracking cylinder walls on #5 and #6 like we kept seeing when the changes shifted the eddy currents away from cylinders 7 and 8.

 

[Will L.]

I’m getting ready to get the 2000 K3500 into the garage to install the new cooling system uprated components.
In @Will L. s thread, a pic of the pump and the backing plate shows that the ports on one side are not matched.
Just looking for ideas and opinions if it would be a good idea to use the die grinder and remove minimal material until the ports match between the plate and the pump.
View attachment 65524

Umm, nope. Not at all what I was trying to imply.
They are shooting from the hip making this pump imo, and getting more wrong than right.

 

[Will L.]

Enclosed body impeller pumps. The name describes the design of the impeller- not its use. Ironically an enclosed impeller pump is best used on an open system. Think trash pump. This takes fluid from one area and moves it to another quickly. But in a closed loop system it continually adds aeration. This is what the flow kooler uses.

An open impeller has the least cavitation. But it can not handle sudden changes in flow and keep efficiency in pumping. This is ideal when flow is constant. Think the little drill driven pump you drive with a drill. One speed all the time till jib is done.

The mix between the two is a semi open impeller pump. This is what almost ever automotive waterpump has used for the last 100 years. Why? It has lower cavitation and handles immediate changes it flow volume and pressure the best while
Maintaining high efficiency. Why does almost every engineer choose this? Because it simply works the best all things considered UNTIL we get rid of drive speed being different than work load and opening and closing thermostat.

There are other way more effective heads. Tesla made a couple- the water turbine is cool.
The most effective pump is the tulip shaped one (can’t remember name right now) but moving water faster and faster without regard to aeration is a big problem.

Ever see pitting on your water pump backing plate? Think that through.

 

[WarWagon]

Serpentine belt reversed direction and caused flow issues they didn’t expect.

And NOT just on diesel engines. The reverse rotation change also affected gas engines.

So the McDonald's 350 in a 4 door 1995 GMC Yukon. Not towing or any of the "Real HD" stuff I am known for. No, really just a DD grocery getter. Sitting in the driveway boiling over and the real WTF moment is the temp gauge is reading NORMAL. Put a new T-Stat in it and new radiator cap, tested both caps: good... no change. One of the few times we have waved the white flag and taken it to the dealer.

We expected a blown head gasket.

The dealer replaced the water pump because GM had balance flow problems on the 350. This is why it was boiling over on the passenger side and the temp on the driver's side where the temp sensor for the gauge is was normal. Not clear on why it showed up at 3 years and 50K. The real sick part is reverse rotation was out in 1988 and this was a 1995 model. That's a long time to ignore or be unable to fix a problem.

 

[FellowTraveler]

I am still of the opinion, that sealing all the gaps around the radiator and placing foam strips on the outer edges of the different coolers "like a gasket" is more than enough to beat back heat by increasing the flow over the cooling stack "BTU rejection" is increased quite a bit.
IMO, GMT400 series is less than desirable in its overall cooling stack design when running any diesel.

 

[FellowTraveler]

Enclosed body impeller pumps. The name describes the design of the impeller- not its use. Ironically an enclosed impeller pump is best used on an open system. Think trash pump. This takes fluid from one area and moves it to another quickly. But in a closed loop system it continually adds aeration. This is what the flow kooler uses.

An open impeller has the least cavitation. But it can not handle sudden changes in flow and keep efficiency in pumping. This is ideal when flow is constant. Think the little drill driven pump you drive with a drill. One speed all the time till jib is done.

The mix between the two is a semi open impeller pump. This is what almost ever automotive waterpump has used for the last 100 years. Why? It has lower cavitation and handles immediate changes it flow volume and pressure the best while
Maintaining high efficiency. Why does almost every engineer choose this? Because it simply works the best all things considered UNTIL we get rid of drive speed being different than work load and opening and closing thermostat.

There are other way more effective heads. Tesla made a couple- the water turbine is cool.
The most effective pump is the tulip shaped one (can’t remember name right now) but moving water faster and faster without regard to aeration is a big problem.

Ever see pitting on your water pump backing plate? Think that through.

Water steaming is the common cause of cavitation in the 6.5td...this is why there are steam lines on them and all the later gas fueled motors.

I eliminated the water in the 6.5td some years ago using Evans...and I remember posting an email from them about boiling off water in the Evans if you happen to get a leak and need to put water in temporarily.

Cummins went to the enclosed impeller design...

The only real change in coolants are in their formulas focusing more on protecting aluminum components which are more commonly used in newer vehicles...

Nitrite-Free Coolants on the Rise Due to More Aluminum in Engines | Transport Topics

As manager of technical development for TA and Petro travel centers, Homer Hogg sells a lot of coolant to fleets of all sizes. In 2010, he started seeing something strange: a white residue plugging coolant filters and coating cylinder liners.

www.ttnews.com

 

[MrMarty51]

With the information that @Will L. has supplied, now I am wondering if I should install the flow kooler pump or just leave well enough alone and stick with the balanced flow OE style pump that I recently purchased from NAPA.
Really has Me thinking of the possibilities of an eventual destroyed enjun.
Maybe it’ll be just a replace the radiator, add water wetter upon refill and while the system is drained add the temp gauge to the RH cylinder head and test the thermostats to make sure that they are opening at the prescribed temperature.

 

[Will L.]

@MrMarty51 YES. Remember not the diesel water wetter, the regular kind- 2 bottles for this amount of REGULAR coolant, ot long life.
Do you play around with different transmission mounts and transmission filters? No, why because the solution for long life is already in place. We know what water pump works with this engine now. We know dual stat with restriction or single stat with block off. The radiator itself after decades of running looses performance and a replacement is required in time. Doing an upgrade there never hurts - @FellowTraveler is on point with sealing up air flow to maximize capability- ask any of the hummer owners that do body lifts- the little gap of airflow makes all the difference in the world to that overtaxed nightmare of airflow design.

I am not on board with his move to Evans. The slower transition of heat from metal to coolant to radiator means harder to get auickly added heat like towing up a steep grade out of the two rear cylinders quick enough and the ring gap difference should tell yall there is a risk there. WAY more concerning to me is the fact that the evans going through the heater core- and what happens if that ruptures. I already know 2 people personally and met a third that have lifetime damages from evans coolant burns. Not talking hot fluid on skin- that can happen with either. I am talking fire- burn ward, skin graphs, fingers burned off in flames, cant be outside in summertime anymore - burns.
You all know I said many times I ran ny fuel pressure gauge tapped at the ip to a mechanical gauge at my dash. Now i dont say anyone to do that. I am pushing electric gauge for that. Why? Because it was f-ing stupid of me to push a flammable liquid into the cabin. Learn from others misery and not mine of worse my families. Hummer a/c is JUNK. Imagine the 1993 chevy a/c except make the evaporator and condenser get less airflow. Then worse ducting in the dash. So I was going to run propane because it cools so much better. That is completely abandoned- why? Because it is STUPID to risk that bad of injury over a little more comfort. Until I saw a couple people I knew going through the lifetime of pain and misery- I was like a teenager “it probably is rare, probably not that bad, and won’t happen to me”.
Nope! I learned, and thank God I learned from others and not my wife or kids or me. There is other solutions that eliminate the requirement of risking burning up in flames someone you care about. What was the line that convinced me? “Will, look how bad I am and I was wearing a race approved fire retardant suit. They got me out and sprayed fire extinguishers on me within few minutes of the fire starting. How long before someone sprays the extinguisher on your wife or sons? Will they be in a full race suit driving to the store? Will they have an ambulance standing by just in case and your family in the ambulance within 15 minutes?”

He was wearing a full fire retarding suit. Enough fluid- about 1 quart estimated- soaked to the suit that the liquid butned but the cloth didn’t. He panicked and ripped off one glove. No thumb or fingers on that hand anymore. The other hand lost tips of 3.
Face neck, and something most people never think of- lungs get burned. Not like ya stop breathing because you are on fire.
With helmet fully engulfed he took of the helmet, face shield was up and liquid soaked the balaclava. Everywhere the liquid got on him it soaked in quickly while on fire. Ever get oil on a shirt? How fast does it soak in- evans is an oil.
If anyone chooses to run evans- fine we are all adults here, make your own choice. But for the love of whatever you love- dont run that shit in your heater core or mechanical ect gauge that brings it inside the cabin. We have knowledge to not need flammable oil as coolant medium-imo use a different option.

As to cummins running enclosed impeller- maybe it will work out long term, maybe it will be like the one of the other forced redesigns that is regrettable later. Lets see long term cavitation inspections to find out. If designed from the beginning for it, we now know how to add aeration extraction chambers, did they do that I wonder?

On the nitrate free- YEAH! Like water wetter- nitrate free for gas engine not diesel which the water wetter is made for high nitrates. I been saying for years no nitrates in the 6.5. We have wrong cylinder design for it. We have aluminum in our system. Same problem with the long life coolants. Completely wrong for our system. The GM engineers learned from fleets like mine that big rigs run heavy nitrates. They asked me about it in our shop. One had never seen a coolant “filter” ever! As soon as you add any non ferrous metal into the coolant system the nitrates have chemo-electric reaction. Its lab 101 stuff. Salts and of center ph plus moving coolant (static electricity) equals electrolysis. Now add extreme heat swings- ambient temperature to boiling temperature change in minutes and back again- time after time- day after day. NO LONG LIFE COOLANT IN A 6.5! Run old school antifreeze with as few minerals in water (distilled water) mixture. The tiny amount of money on coolant and time spent to replace your coolant also has you flushing out the old stuff at 50,000 mile intervals right? Think about it- flushing everything else out is good or bad for the system?! WASTING $50 every 50,000 miles. Also wasting 4 hours to diy it. 400,000 miles. Do the math. Maybe an extra $400, minus the more expensive fluid now is like $250 extra and half the time spent wrenching. Are you doing other stuff at some of those intervals like 100,000 mile hose replacement? Diff fluid changes? Trans service? Or wasting 100% of the time watching fluid drain snd nothing else? Even if nothing else- is it worth the longer radiator life, crossover life, if aluminum radiator- radiator life?

I am good, damn good, at long term cost analysis on fleet maintenance. Remember i am the guy that inly changed engine oil on my 2001 LS suburban every 30,000 miles to not waste the time and money knowing what would be the outcome and knowing I was selling it shortly after 200,000 miles. And I am telling ya- the added cost of old school anti freeze and water wetter is worth it on a 6.5. Neither in my Toyotas. Not in my LS suburban or escalade.

Back to the flow cooler- i just don’t get people on this forum risking an unknown waterpump on anything but a beater 6.5 as experimentation only, knowing the long and checkered history of issues of this engine. Someone that just bought a 6.5 and it’s running warm so they don’t know what to try- ok I get it. An LS or cummins or om603- they can allbe overheated and handle it several times without major damage- so try a new pump all willy-nilly- so what? But a 6.5 you don’t want to have to replace???

 

[MrMarty51]

Man, You have a lot of knowledge. Stuff I never dreamt of.
And here I was more concerned about the fuel pressure tube busting and making a mess. Not once thinking about the possibility of having a fire on top of that.
One of the most horrible scenarios I can think of would be having my carcass scorched, no matter the cause or the reason, then, everytime that truck is on the road, the wifey insists on driving, right there close to the left knee is that FP gauge. What a horrible thought. I had olanned on an electronic FP and oil pressure gauge, but now, I can see these are going to get done a lot sooner than I thought. Like before the truck leaves the garage.

 

[MrMarty51]

Oh yeah, the radiator is now out. The cooling stack is still quite clean. A little dingy bit not near as bad as I thought it would be.
When I first got the truck, I read about the importance of keeping the stack clean, i removed the upper shroud and the grill, got the components that could be moved loosened and then got after it with an old H2O extinguisher filled with a mix of degreaser and water. The oil cooler hoses had at one time leaked but had been replaced and none of the oil washed off. It was quite cold when I did that operation and I was working outside, I didnt know for sure how clean the AC condensor had come but it was plenty clean enough. I could mot imagine the amount of wheat chaff that was embedded in the radiator and the rest of the components but it seems I had got that blowed out quite well too.

 

[ak diesel driver]

Which is also the logic behind the OPS controlling the LP

 

[MrMarty51]

Which is also the logic behind the OPS controlling the LP

I think I got that covered with the pump/harness from Leroy Diesel.

 

[Will L.]

He means the reason they made engine dies and no more fuel can pump, there by eliminating fuel covering people in a crash.

 

[Will L.]

And i used to think same thing about diesel in cab. Smell didn’t other me, so - who cares?.

I just talk to tons of people. Eventually learn enough to listen to them and consider -what if.

 

[MrMarty51]

Back onto the flow cooler coolant pump.
@Will L. if that clear poly 6.5 engine block would happen to still be a available and You would want to do some testing, i would be happy to donate this coolant pump to the cause.
It would be mighty interesting to see how one of these pumps would do as far as flow and cavitation. I would even be willing to pay the postage on it.
Or if there is someone that has heating problems that they have not been able to solve the mystery there of, ai would be willing to donate this pump to the cause. I just cant stand to see it laying here collecting dust.

 

[Will L.]

That is all owned by GM. They didn’t even mention they had it at first. When the engineers showed up and saw what I did, cutting the sides out of blocks- they made a call and it shipped here within about a week. When over, they took it all. Sadly probably all destroyed long ago.

2 sealed flow meters and a modified crossover to accept them is all that needed if someone wanted to make it.