Flow Cooler Opinions Needed.

[MrMarty51]

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.

So would there need to be a modified cross over at the back of the heads ?
It would be nice to have an engine laying around to do some testing with.
I suppose if a person could rig up a pressure gauge and also some clear connector hose they might be able to get a look at air bubbles created by cavatation.
Would need to test between the original coolant pump and the flow cooler unit.
If someone has an old block and wants to invest a little time and money into testing these pumps I would be willing to ship this one.

 

[MrMarty51]

I mentioned the pressure gauge so a person could compare between the stock coolant pump and the flow cooler pumps pressures.

 

[DieselAmateur]

Hope this isn't derailing the thread- I have a question about "balanced flow" and "High Output". I've read that not all water pumps are labeled high output on the outside casting of the pump, and that the way to determine if the pump is high output or not is to measure the diameter of the impeller.

For "balanced flow" though, I've never heard how to identify whether a pump is balanced flow or not. Is there an indicator/ feature of some sort? Or are all High Output water pumps also balanced flow by default?

 

[MrMarty51]

And that is a good question too @DieselAmateur
Not a problem and not considered a hijack. I believe we are all looking to learn a little more about the considerations in the construction of the cooling system components for the 6.2 and 6.5 diesel enjuns.

 

[Rutjes]

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

If it can be done fairly cheap I'd be willing to try this.

I installed a FlowKooler on my friends K30 6.2 a couple of weeks ago (will be running shortly). I have 2 FlowKoolers on the way for my K1500 6.5 and K30 6.5 Optimizer. Off-course, after ordering them 2 FlowKooler threads popped up making me doubt my choice...

I'm really interested in their actual performance.

 

[Will L.]

pumps with v belt 6.2 or 6.5 have no problems

Serpentine driven is where the problems start.
First is 4 bolt pump. (Referring to how fan clutch attatches)
Then was the 4 bolt pump with H.O. Cast into the front. It moves more volume but is not flowing equal amounts through the engine. The HO has a larger impeller closer to the channel wall, with the casting the same as before.

Then the spin on pump is balanced flow. The larger impeller with a slight change in pitch, and changes in the casting through the 90° Direction change area, and eliminated one of the heater hose ports.
Everything I ever read FROM GM and talking to the GM engineers I used to know,and the AC Delco rep we worked with for the generators- AC Delco made a few pumps but all were balanced flow. The different numbers were for ones sent to US plants, Mexico equipment plant, and a South American plant that made generators. They made them under different part numbers for tracking purposes only, and were all cast innthe same facility by Delco.

I Know Heath said he did some testing and found one part number superior to the others. Never saw any proof of it. Never saw a simple pic of 3 different pumps side by side. Never saw a data sheet that recorded numbers or description even of how flow was measured as to do it without disrupting the flow in use. I can describe it easy because it is from memory of what actually was done and worked, not theoretical maybes and could be. Bill helped the 6.5 world way more than many parts sellers, not bashing him ut I call it like I see it always. I called him out on issues on the hummer hood scoop he was involved with and he properly quit promoting it after the other company altered its design according to him and he heard of the lost functionality. called him on advertised fueling misinformation of his tunes, the camshaft improvements and versatility on side mount vs centermount. I am the one who sent him the original write up from GM that got him to consider stopping selling the rear head cooling kits long enough for him to talk to the 1 GM engineer he somewhat knew that wrote him up the letter about the balanced flow issue. Again on that as soon as he learned he immediately quit making kits for sale and started selling the proper parts. He didn’t get the restriction fitting as part of it but that part only drops like 10% variation so it is not the end of the world. So No, I don’t put much (if any) weight on the exact part number he recommended. But the base information he had was not of his own doing- is was GM paying companies and doing in house work to solve it. Is think he is a bit of a narcissist and wanted to take a bit more credit than do him for whatever testing he may have done and unfortunately that backfired to a lot of people that knew his priority 1 has been selling parts, so they don’t trust anything he said. I don’t blame those folks for that opinion, I understand. I just wish I still had papers from GM to prove the end findings so they wouldn’t dismiss the entire concept.

There is a ton of companies making pumps that all say the work and are oem. GM doesn’t care enough to sue over them not meeting oem. Due to cost, we tried multiple off brands in fleets all with poor results. It isn’t that a new brand such as flow kooler can’t make a good one - but so many have failed and the cracked block and/or cracked heads is an expensive way to experiment imo.

If the people at flowkooler had any knowledge, had any information about any testing they ever had done on this platform- it wouldn’t bother me. But look at their entire line. Their entire sales gimmick is this enclosed impeller which is coated to slow the obvious cavitation that would destroy an untreated one in a hurry. Still will eventually chew it up even with the coating.
I work now with big mega pumps driven by 480v 500 hp motors and 4160v 2500 hp motors. So I’ve seen the difference coating and uncoated makes. It helps no doubt but doesn’t solve the issues. Flowkooler is using 1 magic bullet to solve everything. Not every engine all does better with the enclosed impeller pushing more volume. Look up the wet sleeve B series cummins 6bt. They have too much flow. Adding extra nitrates and slowing the flow helps their cylinder linings last much much longer. But according to flowkooler they prescribe the enclosed impeller which increases flow.... Incase ya never thought about it, most parts manufacturers dont buy a car or truck of every kind and do R&D to learn whats best. They buy one or two versions of the parts made, change it enough to not be sued for patent infringement, and market it. Banks is a great example of not doing it that way- they dyno all their engine parts. Remember their axle diff cover videos? Go ahead and find flowkooler’s R&D lab...find their R&D vehicles or engines bought, if sold see if they have economic records showing it... It simply isn’t gonna happen. I have worked with enough automotive engineers over the decades to know when someone knows what they are talking about and when it is a shell game.

For those that bought them- I hope it all works out ok. All that will go on mine is AC Delco after the millions and millions of dollars and years and years of research poured into the spin on pump with the restriction fitting in place.

I know I rant too much. If I didn’t answer the questions lmk and I will focus on more direct & to the point answers.

 

[Will L.]

A link to that other thread. And i will copy my own last post here to show the difference

Flow kooler FAIL

One of the hummer guys posted pics of his new flow kooler bolted up. Found out his engine was toasted, so didn’t get a lot of time on I guess. But did post pics. Call them up you say? I quote “I called FlowKooler about it and the representative said that there wasn't anything that they could...

www.thetruckstop.us

 

[Will L.]

Ok. 3 texts, and 5 pm’s across the 2 forums... this is a balanced flow water pump with the backing plate on it. Later this weekend i can dig out a 4 bolt and show it. Yes I believe some aftermarket pieces of junk (edited for trying to quit swearing) are made with fitment as bad as flow kooler. But I have never seen an AC Delco fit so bad as the flow kooler did. The plate isn’t bolted, just set on it- yes slightly off, but the bolt holes are slightly off.
would I port match the backing plate to match any pump including AC Delco? NOPE. Not unless i put a 1993 plate against a modern plate and saw that GM (idk who stamps the plate if not them) made a change. Y? Because they made it work with this plate. And messing with the flow in the pump is exactly what I would avoid- they spent millions, until someone matches that amount or a good portion of it showing why- don’t mess with it because small changes made big effects in the flow.

 

[93detroit]

Thanks for sharing your knowledge and experience Will. Could you post a pic of the restriction fitting in a spin on pump? I put a NAPA rebuild spin-on pump on my truck before I ever fired it up, but I don't remember any sort of restrictor ( I honestly didn't even look- just went with opinion that it was the best pump to have).

 

[Will L.]

They don’t sell it with the restriction fitting because of legal issues with the family that owns the patent.
Leroy sells a super nice made one.
N8in8or did a simple diy version with a screw in plug that he drilled.

Basically you need it to be a 3/8” hole that is at least 3/8” deep hole, it can be deeper but not more shallow or it will cause more cavitation.

 

[DieselAmateur]

Also isn't the restriction fitting only for the dual tstat setup? @93detroit if you have the single stat you don't need it as the single set up is block off style while the dual isn't and allows hot coolant back into the block, hence the restriction fitting slowing the flow and diverting more coolant to the radiator

 

[93detroit]

@DieselAmateur, got it, thanks!

 

[Rutjes]

At first I talked with my guy at USA2YOU.nl about returning the FlowKoolers, but decided it would cost to much. Re-stocking fees, reimbursing the free shipping and the return shipping. On-top of the price difference with AMG pumps.

But, I actually lost sleep over this. So I just told my middleman to return the FlowKoolers and get AMG pumps from @Twisted Steel Performance. I already have this much money into my trucks a couple hundred wasted, well, too bad. Definitely don't want to ruin the Optimizer 6.5 by cheaping out on the waterpump. I have 2 spare 6.5s and 2 spare 6.2s laying around, but only 1 Optimizer which is destined for my M1008. They are rare enough, especially on this side of the pond.

 

[Will L.]

Here, here, careful, what would ever convince you that good ole racing started in these here Appalachian Mountains......

You know it started with moonshiners hauling shine, but maybe it was something else, maybe these ole mountain boys wanted to test a vehicle to the limit, in the curves on the edge of the mountain. I never hauled any shine, but I burnt up some dirt country mountain roads. No wonder the drivers ed teacher told me when I was 15 years old that I drove those country dirt roads real well....

I learned to drive at our farm on dirt roads at an early age, it was legal, it was private property and I would slide one sideways now and then.....

Also isn't the restriction fitting only for the dual tstat setup? @93detroit if you have the single stat you don't need it as the single set up is block off style while the dual isn't and allows hot coolant back into the block, hence the restriction fitting slowing the flow and diverting more coolant to the radiator

YES 100%. Only use restrictor fitting if dual thermostat housing.

Only use single stat if it is block off style.

If you have a single stat non block off-mount it on the wall as a coat hanger.
I have the original single stat non block off from my hummer- there are some guys that restore hmmwvs and never drive them much so they want original- so if I find one of those guys I will sell it to them- otherwise no one should run that type. Like a collectable gun that fires of by itself- not worth owning unless ya rea

 

[MrMarty51]

I too bought the NAPA brand coolant pump. That in itself might be part of the cooling issues with My truck.
I also installed the restrictor fitting into the crossover thermostat housing instead of in the coolant pump. I didnt want to forget the fitting when and if I ever need to change out the pump. Not on the 6.5 but I did once do that with just a hose fitting.
Might be I should install a Delco pump and move that restrictor fitting to the pump.
Any opinions on that ?

 

[MrMarty51]

I wonder, on setting up to test the flow cooler pumps, if it would be best to use an electric motor, with proper size pulley and correct RPM to imitate the flow of the pump at approximately 2000 RPMS, instead of having to run the engine.
Then clear hoses to be able to tell if cavitation is taking place.
It would probably require a very low pressure gauge to see what pressure the pumps are producing and the flow meter for GPMs.
This has been the most educational thread on the cooling shstems for the 6.2/6.5 engines that I have ever come across.
Thank You Will L.

 

[Will L.]

I too bought the NAPA brand coolant pump. That in itself might be part of the cooling issues with My truck.
I also installed the restrictor fitting into the crossover thermostat housing instead of in the coolant pump. I didnt want to forget the fitting when and if I ever need to change out the pump. Not on the 6.5 but I did once do that with just a hose fitting.
Might be I should install a Delco pump and move that restrictor fitting to the pump.
Any opinions on that ?

Yes, do it.
The restriction fitting doesn’t work up there as well. I can explain, it probably take 5 paragraphs to do it- but yes it makes a difference.

Yes I would swap out the unknown pump at a planned time.

Yes, we used an electric motor to drive the water pump for testing but it is an additional expense and more work.
For in use truck testing, cutting up a thermostat crossover and welding in a couple flow meters is the “A” answer. Junkyard $15 and the two flow meters is the expense. Then a little time welding. I can’t do that stuff nowdays because no more tig welder. Flowmeters can be bought for under $100 on ebay. But just a couple big loops of pipe welded in to fit the meter up above, And its done.

It would be awesome to test a thought a couple people had that Delco may have altered the HO pump by now ,as casting wears out the mold and making the casting changes to the 4 bolt mold wouldn’t be that big of deal to copy the coolant flow part from the spin-on to the 4 bolt. Then those (like me) that want to run the hmmwv set up could do it easy with the 4 bolt and not worry about it.

As much as I normally love doing testing and comparisons and the like- I have neither the money nor tig anymore. And the amount of time I am able to do stuff in the garage- is needed on other projects, one of which would be my hummer.

I still have parts laying around for wanting to build the spin on to Hmmwvs fan clutch adapter. The two I made that wouldnt work so far, one self destructed -expectedly made it weak incase of failure didn’t want bigger parts failing, and the other I had mocked up and sent to machine shop as sample to try having cnc made ones. The price of scanning in and making changes was quoted at $600, but then half way through the work he called back with a price correction of$4000 more. So in the end he refused to ship it back and I told him to store it in a certain dark location on his person... I would want to tackle that still first but may never since ak diesel driver shared his genius idea with us. If that system had been marketed and sold for $999 each or something near it, 80% of hummer owners and probably 250 pickups would have it by now. But because it is just free information for folks to diy- it isn’t being done much. Afaik Maugan was the first hummer that was about to have it but he rolled his hummer in a crash (everyone ok) and he probably won’t get another hummer. He even had custom switch made and coolest audible warning for shutting off fan during deep water crossing.

 

[MrMarty51]

It would be wonderful to be able to get that clear plastic block.
I too do not have the equipment for building the components, nor the money it would take to get it set up.
Without being able to have a visual of how the coolant is flowing through the coolant passages and jackets within the block, I dont know how much success such an experiment would produce.
Unless there was a way to do a visual at the back end of the block where the coolant could be flowed through a clear hose and see how much air bubbles is being produced, then a valve to shut off the hose on that side and open the hose on the other side with both hoses being able to recirculate back to the radiator.
This is testing that flowcooler should be willing to finance, but, through an independent testing facility to keep out any bias or false claims.

 

[Duvall]

I will step in and say that I have a FlowCooler pump installed on my 18:1. I don't really have anything to compare it to. I have always run the 4 bolt pumps before this because that's what my fan was and I wasn't aware of a better pump at the time. I had never had cooling issues with this truck in the past. Just head gasket blow outs.

The FlowCooler I have is the spin on type and I am using the AK spin on fan with electric clutch. My engine does not have a lot of run time as of yet. I can say that the few times that I ran it when the ambient temps were in the mid 80's and the A/C running the engine temp was a little higher than I remember it being before. This is a new engine with very few miles on it, so maybe break in temp? I don't know. Recently the engine temps seems to be inline with what I remember it being.

I have thermocouples installed in the back of both heads. Once the engine warms up and the thermostat is open they both read around 195-198 degrees at cruising speed. I have nothing to compare this to.

My plan is to do the following.

Get my truck out the next time we are in the high 80's for ambient temps and drive around with the A/C on and monitor engine temps and record what I see with different scenarios. (acceleration and towing, etc)

If someone can get me the part number for the end all GM pump I will buy it and install, and repeat the process to see if there is a difference.

That's about as far as I can go with seeing a difference.

 

[MrMarty51]

I dont like having to wrench on any piece of equipment anymore than I have to.
At this point in time, with the RR cylinder temp gauge installed, i am thinking I will leave the 195 T-Stats in place, keep the NAPA coolant pump, put this all back together and run it hard when the temps get into the 100s or close. Moniter coolant temp and head temp. See where it goes with the coated radiator.
If it heats up to that 117 again then try the 190 stats. And eventually to the flow cooler pump for a short time, see what difference it makes and, even if it cools well, remove that pump and install the Delco unit.
Doing all this with the KD fan clutch, then getting the supplies gathered to do AKs thermal fan setup.
Thats about the best I would be able to do for a Flow cooler test.
Oh yeah, and gather up a new coolant pump backing plate for the new Delco pump. It seems there was some mild pitting on my old one.
If I cant find one, then see about having the welding shop over here that has the computer plasma machine, have them cut one from stainless.
If stainless would be advisable.