Sucked Near A Quart of Oil, Temp went to 210.

[Twisted Steel Performance]

We don't need to see the backing plate, we need to see the pump impeller, that's where the flow originates...

 

[MrMarty51]

We don't need to see the backing plate, we need to see the pump impeller, that's where the flow originates...

I thought the blockage of the pump to the backing plate would affect the flow.
The old NAPA pump.

It appears it had been slightly dragging on the backing plate but the BP does not show scuffing.
CKO.

New AC Delco.

 

[MrMarty51]

And this is the higher volume, higher pressure pump that Leroy Diesel was selling.

 

[Will L.]

That orange one is the “flow kooler” brand. I caught them in lie about the volume it flows. Leroy accepted it was doing the volume the manufacturer says it does, like all their victims. Last I heard from that outfit they were going to go back to testing to get the volume up and verify it putting out balanced volumes- but they never got back to me and when I contacted them about a year later- the new guy knew nothing about the guy I spoke to who quit and the company wasn’t doing any testing…

 

[MrMarty51]

That orange one is the “flow kooler” brand. I caught them in lie about the volume it flows. Leroy accepted it was doing the volume the manufacturer says it does, like all their victims. Last I heard from that outfit they were going to go back to testing to get the volume up and verify it putting out balanced volumes- but they never got back to me and when I contacted them about a year later- the new guy knew nothing about the guy I spoke to who quit and the company wasn’t doing any testing…

What do You think about doing some die grinding on the new AC Delco coolant pump so that the backing plate and the channels in the pump align a little better ?
Kind of like grinding heads to intake manifold ports for a more undisturbed flow.
Would that help on the flow from the pump to the block ?
Its not much of a misalignment but it might have a slight affect on the flow.

 

[Big T]

What do You think about doing some die grinding on the new AC Delco coolant pump so that the backing plate and the channels in the pump align a little better ?
Kind of like grinding heads to intake manifold ports for a more undisturbed flow.
Would that help on the flow from the pump to the block ?
Its not much of a misalignment but it might have a slight affect on the flow.
View attachment 93966

Not sure what you’re getting at. It looks like flashing is present on the hole to the right and to the left the backing plate is misaligned. If that’s the case, I would grind the flashing off on the right and grind the plate on the left. Before I’d do any of that, I’d pull all the bolts to see if the plate will align with the water ports, then adjust/grind the bolt hole holes.

Something is up for this alignment to be consistently wrong across a number of water pumps, especially when no one else has experienced it.

 

[Twisted Steel Performance]

You can match that little bit and grind it if you want, if you line it up before tightening the bolts it won't be like that.

As for the w/p's, this is how to tell a higher flow vs a standard flow pump tight is high flow, a gap like the flowkooler is lower flow...

FYI, flowkooler now has one with a bigger impeller like the high flow others ....

I see nothing wrong with the pumps you posted....

 

[Will L.]

Big T has it right on start with alignment- it seems to me your backing plate isn’t quite right. Mass production has errors. And ANYTHING CAST that has flashing- always remove it.
Anything that helps flow to the passenger side is ok. But remember, just like people trying to port heads make errors: bigger is not always better. “Gasket match” yes. But look how the holes line up on the block to the plate. Then plate to pump. If you make pump& plate match but they aren’t aligned with block entrances, it doesn’t matter.

And yes Chris is on point to hi flow vs low flow and the gap at the wheel.
Afaik flow kooler never fixed their issues, and were in-fact having worst fitment issues of all. So imo just skip them.

On the different Delco pumps- look at the pic you posted and Chris posted. Two different pumps and one has a restriction in flow to the driver side, the other doesn’t. Idk if this is error in casting or something that affected one being balanced and the other not. Could be something to id, might be ignored. Imo run ONLY the one identifed as balanced by the part number. We know Bill was selling it and some believe he was “pushing it” but he could have “pushed” any of them.
And that number was the one identified by the GM Engineer.

 

[MrMarty51]

The weird thing is the old original backing plate fits all the pumps exactly as the Quad Star backing plate.

 

[MrMarty51]

Engine was cooling real nice with this pump.

Engine was not cooling good with this pump.
Temperature gauge before I got home was running on the 220 peg.


This AC Delco pump is closer to the pump that was cooling good.
I think.

 

[Big T]

Engine was cooling real nice with this pump.
View attachment 93974
Engine was not cooling good with this pump.
Temperature gauge before I got home was running on the 220 peg.
View attachment 93975

This AC Delco pump is closer to the pump that was cooling good.
I think.
View attachment 93976

These were all tested on the 6.5 Optimizer? If so, I would stick with the new AC Delco. I also commend your efforts to swap these in and out so quickly.

On the bad Chinesium, the pump vane does not look like it’s attached solidly to the shaft. Could it be spinning on the shaft while under load?