Sharing a find, HO waterpump

rvitko

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I am starting on a 7.3 IDIT build and have been looking for uprated parts, I found this and have one on order-


I am early in the build, right now I am still in tear down to get the block and heads off to the machine shop but I am always searching for better parts.
 

YJMike92

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That looks interesting. Keep us posted on your impressions once you have it, and more importantly once it's in use.
 

chillman88

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I'm going to try one when I go through mine. But I know @IDIoit had a brand new one leak on first start, not a very comforting thought.
 

YJMike92

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I hope to get back on my engine rebuild later in the summer. I might give one a try although the pump on that engine has less than 5k on it. In theory, it sounds like a good idea. Although more flow equals less time to cool down in the radiator?
 

jrollf

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I hope to get back on my engine rebuild later in the summer. I might give one a try although the pump on that engine has less than 5k on it. In theory, it sounds like a good idea. Although more flow equals less time to cool down in the radiator?
That's what I was wondering, more water flow isn't always a good thing. It will be intersting to see what kind of results you get.
 

rvitko

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I used an ho pump in a Chevy 6.2 build in the past and my understanding is the benefit is the pressure more so than flow, it gets more coolant flow to the back cylinders and helps with cavitation issues. It’s more about keeping coolant moving as you get away from the pump.
 

TygreII

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FlowKooler has a bit of a wait time right now. So order ahead and plan for a wait. I cancelled my order with them because I wanted it sooner.
 

IDIBRONCO

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This isn't about the pros or cons of the higher flow of the Flow Koolers. It's just what I've found with the stock pumps. When I got me Blue Truck, the thermostat was stuck open so I wanted to change it out. It had a piece of threaded metal in it that looks like either aluminum or pot metal. I showed it to Wes one time and he agreed with me that it's a part of a broken 6.9 glow plug controller. There's nothing else that it could be. When I was overhauling the 7.3 that's in the truck now, and I was doing the cooling mod, I accidentally knocked one of the plugs inside the block. I couldn't get it out and decided to leave it since it was stainless and wasn't going to rust. I found it underneath the thermostat when I was changing that one out. Going off of these two pieces of evidence, the stock water pumps seem to have plenty of flow to me.
 

Big Bart

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One nice thing about these trucks is when you have the stock water pump, a Motorcraft thermostat, and original copper/brass radiator is they do not generally have any cooling issues. They made the cooling system to have a lot of capacity even while towing. Now climbing a long and very steep hill might mean letting off the pedal some but still if you do, they do not overheat and cause you to pull over.
 

rvitko

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Good to know, when I got mine I had a ton of issues but they were wrong thermostat and a goober who rtv the bypass port. No issues since fixing that, but I’ve been nervous about installing the uprated turbo diesel. Still on the original brass radiator.
 

snicklas

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This isn't about the pros or cons of the higher flow of the Flow Koolers. It's just what I've found with the stock pumps. When I got me Blue Truck, the thermostat was stuck open so I wanted to change it out. It had a piece of threaded metal in it that looks like either aluminum or pot metal. I showed it to Wes one time and he agreed with me that it's a part of a broken 6.9 glow plug controller. There's nothing else that it could be. When I was overhauling the 7.3 that's in the truck now, and I was doing the cooling mod, I accidentally knocked one of the plugs inside the block. I couldn't get it out and decided to leave it since it was stainless and wasn't going to rust. I found it underneath the thermostat when I was changing that one out. Going off of these two pieces of evidence, the stock water pumps seem to have plenty of flow to me.

Yea, what I am seeing in the coffee table book for the 7.3 IDI Turbo (and I think Ford used the same water pump for all 6.9/73. IDI's, all the cross references I can find for water pumps show fitment for 1983-1994) is the cooling system flows 79gpm @ 3000rpm. So it is moving 79 gallons a minute at 3000 rpm, and it says fan to crank ratio (which the fan and the water pump share the same pulley) is 1.1:1, so the fan/water pump turn a bit faster than the crank. The fan would only be that speed, at full clutch lockup, the water pump would be that all the time.

So if the flow were directly proportional (which I don't think it is... some one out there able to do the flow math?), then it would be 39.5 gallons a minute at 1500 rpm.... so yes, the factory water pump moves a lot of water.... what is the spec of the flow cooler...

Here is the chart that I pulled that from... there is some interesting information on there:

You must be registered for see images attach
 

03wr250f

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@snicklas that is fantastic information! love it I haven't been looking hard for this information, but i had not yet seen this info. do you have any more information? I would love it if you had any more if you could send me it! I have email, text, or fb messenger.

as far as the flowkooler water pump im on the fence. I would love to try one, but i have a new motorcraft water pump, thermostat and champion 2 core aluminum rad PLUS my 9 blade plastic upgraded fan and it stays cool, and cools well when the fan clutch locks.

believe me before deciding to develop my fan, i looked into many options including the flowkooler for better cooling for a idi. I would honestly love to have 2 identical setup trucks (turbo, motorcraft thermostat, champion rad, etc) and having the water pump be the difference and tow a trailer, see what the cooling differences between them are. I would even be satisfied with someone who has good aftermarket gauges and some data logs did a before and after. Honestly my truck would be a great one to do it to, but I doubt I will get to it for a long time.

Under theory, it may hurt cooling because the water flows too fast and is not in contact with radiator long enough to transfer heat well enough, and I honestly think that if the engineers of Navistar found that it would help to flow faster they probably would have. (but i also know production decisions are made based on a variety of factors only one of them being performance, others being cost and time.)

But there also may some benefit to increased flow and possibly pressure to move coolant through the motor faster.

my thoughts... I dont know.
 

rvitko

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I plan to use it with your fan. I have taken a lot of your guidance and will have a similar build out. It’s debatable if the flow is that much higher. The main thing you notice on high output pumps is where you may have a 1/4” or more between the impeller and volute in a stock pump, that’s like a dime width on the HO types, that equals pressure. With that said, one stray chunk of rtv or some deposits letting go would be way worse as would any bearing play but if you have a clean new system, I think the pressure is a benefit and I understand a cooling system is under a set psi more by the vapor pressure but you are pushing the water harder and displacing and flash vapor on a hot part.
 

snicklas

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I will try and post that PDF on here later (it’s on my PC and I am not at it at the moment). If it won‘t post due to size, I will send it to your on FB Messenger….
 
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