FlowKooler pump and overall pressure?

[MtnHaul]

I just ordered up a new radiator from Classic Diesel Designs and am tempted to install a new water pump while I have everything apart. The FlowKooler website doesn't seem to offer any flow or pressure data but claims to increase both. I run a 7lb radiator cap and am wondering if the lower rated cap combined with a higher pressure pump is a bad combo for any reason. Am I just negating the higher pressure from the pump by using the lower rated cap? Will I get even more fluid in the overflow tank? I'm not trying to have a high pressure cooling system. I would have no problem installing another Motorcraft pump, but they don't seem to be available--any recommends on a decent water pump?

 

[FrozenMerc]

What you really want, and you will never find because it is proprietary information, is the flow curves for the pump. I.E. Flow vs head pressure at certain RPM's.

At a previous job, I designed and built a water pump dynamometer that consisted of an electric motor, torque cell, water pump, radiator, and a throttling valve in place of the thermostat. I could play around with different impeller designs, operating speeds, involute shapes, etc and see what worked best, consumed the least amount of power, and met the design engineers goals.

The pump head pressure (controlled by down stream flow restrictions, impeller rpm, and impeller shape) is different from the system operating pressure that is controlled by the radiator cap.

The system operating pressure is generated by the expansion of the liquid as it heats up and expands within an enclosed volume. It is uniform throughout the entire system and dictates the boiling point of the coolant. The pump head pressure is highest at the outlet of the pump and drops off through out the system to a low point inside the radiator, or at the inlet to the pump. If you were to put a pressure transducer at the pump outlet (and I have done this), you would likely see 35 or 40 psi of pressure (or more) with the thermostat closed and high engine rpm. But, that high pressure is generated because the pump flow has no were to go and is essentially dead headed.

I guess that is the long way of saying that changing radiator caps will have no effect on the flow rate of fluid generated by the pump since system pressure is the same on either side of the pump. The only thing that changes the pump's flow rate is changes in down stream restrictions, or changes to the pulley size.

I guess, buy what ever you can get your hands on and go. I have always been a fan of quality remanufactured parts as they should be built back to the OE's original specifications.

 

[MtnHaul]

That makes sense. So the rad cap controls overall system pressure regardless of variation in pump pressure.

 

[KansasIDI]

I had the FlowKooler water pump on the 7.3 in my 86

That motor is just sitting in the corner of my shop now.

Never got hot though.

Would probably buy one again if my 91 needed one. But it has very low miles so it probably won’t need one for quite a while

 

[IDIBRONCO]

I just ordered up a new radiator from Classic Diesel Designs

When I saw them, I would have bought one myself just to try them out. Unfortunately, I had just ordered a set of new trailer tires so that meant no CDD radiator for me.

I have always been a fan of quality remanufactured parts as they should be built back to the OE's original specifications.

Same here. I do know that Flow Kooler has been around at least since the mid 90s so they should be a good place to buy from. If they weren't I'm guessing that they wouldn't still be around.

I had the FlowKooler water pump on the 7.3 in my 86

So what ever happened to that truck anyway? You only seem to drive your Superduty around anymore. That would be great for your line of work, but not so much gun to drive down the highway empty.

 

[Rocknit4x4]

I have had a FlowKooler water pump on a Jeep Cherokee for a few years now. Not sure how the IDI version works, but it worked well on the Cherokee where i had consistent temp issues (big winch directly in front of the radiator, slow speed crawling over rocks) - didnt solve all my issues under those conditions but it definatley improved the situation. Cherokees are known to to have overheating issues but the water pump helped for sure.

 

[KansasIDI]

So what ever happened to that truck anyway? You only seem to drive your Superduty around anymore. That would be great for your line of work, but not so much gun to drive down the highway empty.

Well… I did something stupid. Actually multiple stupid things. It’s kind of a long story…

About a year ago I blew up the front diff. Had it in 4WD on an ice covered highway. Well I got up to a roundabout that they had salted real good and forgot to take it out of 4WD. But while the pavement was salted, it still had some slickness to it.

There was no one else at the roundabout, and I can be one hell of a fool driver. I spun it around the roundabout a couple of times, and upon my rip-roaring exit, I heard a pop and the truck kinda ****** to the right. Got out and oil everywhere, actually broke the case.

So then later on, I swapped the front axle to a Dana 60. Crisis averted…

Had my power steering pump go bad and caused my gearbox to bind up one day, put me in the ditch. Messed up my front bumper a little, but no other damage.

Put in a non power steering gearbox, and drove on.

Had one of Russ’s injectors fail, got that remedied easily at the time. God bless him, we all miss him.

Then… one morning I thought it would be fun fun funny to powerslide away from an empty intersection… bad idea. I managed to literally blow apart a ZF5. Actually shattered the case and sent shrapnel all under the bottom of the cab. Had a few pieces fly through the floor and hit me in the leg. Only needed 5 stitches from that, could’ve been much worse. Well anyway all kinds of stuff got screwed up, punctured the oil pan, damaged the fuel lines, messed up the flywheel, and lots of damage to the truck.

I pulled the engine to replace the oil pan, but haven’t done anything further.
Mostly because I no longer have much need for that sort of truck. Kinda sad. That’s what I get for being hard on gear I guess…

Unfortunately it wouldn’t be too much longer before rust would kill that truck…

My 91 F-Superduty is currently better aligned to what I need out of a truck. It definitely screams and eats fuel on the interstate, but it can do it all day… pulls trailers like a champ.

And for the most part at work, I use the company truck I was issued. (2019 Ram 3500 MCLB) Most long distance trips I take are for work, so it’s not that big of a deal. Funny though, right now I am in Colorado, for personal reasons And no, I didn’t drive no company truck…

So, I feel I get along pretty well with my 91, and without my 86, but that doesn’t mean that I don’t miss the ol rig.

If it weren’t for rust, I’d be more inclined to fix the old 86 back up… but I’m afraid that I’ll have to move on. But at least I can use the 7.3 and Dana 60 from that truck in something else… like in another truck like my old one especially since I do have ZF5s laying around…

If, y’know, a nice one came along… for a good price… like I got time for that… who am I kidding. I’ll probably have to play it by ear, like I always have.

 

[KansasIDI]

Kinda funny, all my incidents I’ve had in vehicles have been really close to home… except for the front differential exploding, that happened about 70 miles from home. And most of them have been the consequences of me doing something stupid… at least I don’t do it where I could put others in harms way… showing off is very dangerous. Have had one mishap in my Dodge, spinning the rear tires up on a snowpack road and then sliding into a very deep ditch… and on the other side of that ditch was the shed

 

[KansasIDI]

Why can I say

Damn it all to hell

But I can’t say

J E R K E D

 

[IDIBRONCO]

and I can be one hell of a fool driver.

Oh go on! Not you?

 

[MtnHaul]

That ZF carnage sounds impressive. I guess if you're going to destroy something it might as well be total annihilation--half measures are for wimps. I mean, who gets a shrapnel wound from their transmission?

 

[KansasIDI]

That ZF carnage sounds impressive. I guess if you're going to destroy something it might as well be total annihilation--half measures are for wimps. I mean, who gets a shrapnel wound from their transmission?

I’m the only person I know who has… but surely there are others.

 

[IDIBRONCO]

I mean, who gets a shrapnel wound from their transmission?

It sounds like he needs to come up with a different shaped scatter shield like drag racers have to use.

 

[The_Josh_Bear]

@KansasIDI For what it's worth, I appreciate you being a Hoonigan away from bystanders! I'm all for getting sideways and stuff as long as you're the only person you can(potentially) hurt. That's totally nuts about the ZF5 shrapnel! I wouldn't ever have thought somehow that flying bits would pierce the cab like that.

@MtnHaul I have a FlowKooler on my 7.3 and a 7lb cap. Works well. I agree with @Rocknit4x4 that like his Cherokee, it helps but doesn't fix anything. It's a part of the complete system.
My example:
I have e-fans for cooling that don't keep up when towing. Because of this, I can easily test new cooling mods! I installed the FlowKooler without any other mods and it kept the temperature away from "shift into 4th and slow down" mode on a hill that usually requires that. Driving around more I found that it would still creep up on much bigger hills giving it full steam but it took much longer to push 230*.

 

[YachtTech82]

Did you ever go with the flowkooler pump? I have one sitting on The bench waiting to be installed later this week. I will be flushing the system(with original radiator) and filling with delo ELC. I will report back.