This is scary.. Stolen from HTT..

I assume left to right on the changes but don't know how the scavenge side mates up with the feed side.. Feed side first 3 show relief valve mods in the body. The 2 valves show initial and back to the TC valve. Scavenge shows the scavenge port getting smaller. At least from what I see.

 

Here is the pump tagged for install per the SB addressing sumping.

 

how the #$@% could they have effed this up so badly..didn't they start the design and testing several years before production release..blows my mind..especially with the Lead Engineer bragging about how unprecedented their diligence was on this project.

"We have about 1.5 million miles on this product already. This is the most heavily analyzed and tested product we’ve ever done."

and my favorite quote....how'd that work out?

“It was exciting to work on a clean-sheet design.” In addition to meeting design, budget and scheduling targets, a big part of his job was to make sure the entire team worked together rather than isolated in silos. No one was allowed to “hurry up” to finalize a particular component or system and “let the cement dry,” forcing everyone else to adapt to something that couldn’t be changed. “No one was done until we were all done,” he said.

 

I'm pretty sure three of those pumps pictured are original part number pumps (not changes in response to sumping problems) and I suspect a fourth one is too. That pic appeared on another blog before it got to HTT. It wasn't very clear which pumps were out of the original design batch - the M8 started life with four different part number oil pumps - one each for the oil and twin cooled engines and another two "high flow" (note that HD didn't call them "high capacity") for the Stage 2 kits for the oil cooled and twin cooled engines.


That would mean there hasn't been four different pumps designed to fix the problem, only one or two (most of the MoCo press says there's only been one redesign) - depending on whether or not the other two in the pic are differentiated for the twin cooled and oil cooled models.

 

there were 2 oil pumps from M8 inception designed specifically for Stage II "kits"?..first I've seen or heard mention of this..if that were the case you'd think they'd be included in the PWR and TQ cam kits

 

A new TSB just came out recently, My 2018 Ultimate Limited was manufactured in Oct and they are putting a new version of the lastest pump in, I have not read it yet, Something about this one has 2 drillings that you can see versus 1 drilling???
I am getting a Stage 4 to make mine 114 and I had to ask about the oil pump issue, They called Harley tech line and got the TSB that supposedly just came out.

 

First off the 3 showing pressure side, are all oil-cooled head pumps.. The gerotor cavity looks to be all the same size and it's about the same size as the scavenge side. With them about the same size, part of the feed side has to be used for cooling or the scavenge side would not be able to keep up.

What you are calling high flow was really something someone called high velocity. It's the scavenge side pump body with the smaller scavenge orifice on the far right of the picture.

As mjw says, originally there was one pump each for liquid and oil cooled (feed gerotor size different). The pump changed when the motors were found to sump and only after that. They then required the high velocity (high flow?) pump on the stage 3 and 4 to stop the sumping issue which appears to not have worked.

 

The oil cooled engines has a differant pump than the twin cooled engine, I was told the oil cooled pump was HIGH Flow, and they are not interchangable, I wanted a high flow/velocity pump for my Stage 4 kit install and asked if I could use that and was told no by LaidLaw Harley it was differant, But dont no why,,, an 8 is an 8. The lastest pump was put in production in 10/10/18, I plan to get a pic of Pre Oct version and later Oct version and post.

 

There are some miss conceptions here.. Yes. The oil cooled pump flow more on the feed side than twin-cooled motors.. It's required since only a portion of the oil from the feed side pump goes into the motor. Adding this pump to a twincooled only serves to mess up the scavenge side pump which is the same size between the 2 pumps..

The things to note are that the HD uses a dry sump system which means it is really 2 pumps. A feed pump that generates pressure and a scavenge pump that sucks oil out of the crankcase and cam case. If you increase the flow in you need to increase the flow out. The oil cooled pump does not do this as it pumps a portion of the feed side capacity through the heads and directly back into the oil tank..

You don't need a high flow pump, you only really need enough flow to keep everything lubricated and minimal cooling. Most of this motor is roller / needle bearings they don't need much flow or pressure. Only plain bearings are cam-plate, lifter holes , rocker and upper connecting rod bearings. These all work well with minimal pressure. Pumping too much oil into a motor with flywheels that fill the cases only creates severe misting, foaming and other possible oil control problems.


If you take pictures compare the gerotors as the define the capacity of each pump section. Also take pictures of both sides of the pump.

 

I agree, That is what I was told, I just wanted the new version pump in my 4 stage build, The bike only has 100 miles on it and didnt want to get thru the hell that I have been reading about cylinder and bearing failure with the last 3 sets of pump versions