Oil pump casting

[Sunny Jim]

Highly frustrated! Carried out a top end build 117 on an early 107 M8. aprt From HG issues the bike  Sumped.
We dismantled the engine and reassembled it very carefully .
We installed an SS cam plate and oil pump.
Ran the bike today for approx 50mile and it  sumped. Drained the oil from the CA sensor 900ml. Installed sensor and rode around several locks- sumped again 400ml.
Pulled apart the cam plate and  pump. Everything is in order except I noticed there was no evidence of the new ( and old ) camplate pressing hard up against the crank case casting . A straight edge across the holes indicates a gap of approx 2-4 thou.
Is this normal or indeed , acceptable? I have posted photos indicating the main oil pressure port.  [attach=0]

[Sunny Jim]

 I probably haven't explain this well but the bottom line is that there is a gap between the Cam plate and the crankcase at the main oil discharge port. Only the the main port, not any other holes.

[rigidthumper]

"I think" it's possibly an internal leak, but I'm not certain that's the cause of sumping.  Oil released in that area would tend to stay in the cam cavity, to be picked up by the return port. 2-4 thou is thinner than the size of a human hair- may be enough to justify machining a groove and using an oring to seal it.
Did you check the piston squirters & gaskets while you had the top end off?

[VDeuce]

I've heard of a few sumping with the S&S. Have you considered trying Feuling? Do you run the oil low? How are the breathers set up?

[Sunny Jim]

"I think" it's possibly an internal leak, but I'm not certain that's the cause of sumping.  Oil released in that area would tend to stay in the cam cavity, to be picked up by the return port. 2-4 thou is thinner than the size of a human hair- may be enough to justify machining a groove and using an oring to seal it.
Did you check the piston squirters & gaskets while you had the top end off?

I checked the screws on the squirters and they were not tight. At least 1/8 turn to firm them up.

[Sunny Jim]

I've heard of a few sumping with the S&S. Have you considered trying Feuling? Do you run the oil low? How are the breathers set up?

That doesn't help unfortunately. I haven't heard that t all, and in fact I was recommended an SS pump and plate.
Might I add, this occurred with the original Cam plate and pump with the new oil sealed backing plate. It has The same  issue as well where it matches up to the crankcase.
I reckon this problem existed when it was a 107. I though my performance had dropped off! But never realised oil in the sump. One could assume there is always some oil in the sump.
But now I am at a loss.

[VDeuce]

Did you replace the piston oiler gaskets? The stock gaskets have an adhesive film that breaks down, possibly contributing to the slop. Cometic makes a nice set with no adhesive. Also remove the oiler and run the self tapping screws in farther to run the threads in a little deeper and make sure the mating surface is flat. I also loctite the screws.

There are threads around here on this.

You are not the only one that has said they sumped with the S&S unfortunately. Good luck!

[Sunny Jim]

Ta, VD. I am at a loss as to where to go from here.  I th8nk I now have to strip the engine, possibly check all castings, oilers etc.
this has been a costly set of circumstances, and where I am located there is very little, if any experience with M8s.
One can be completely competent, my if the design is faulty, then it's faulty.
Possibly Durwood or GMR might chime in.

[VDeuce]

I would probably pull the jugs and replace the piston oiler gaskets at min, since these are known to cause a problem. There is a video somewhere around that Steve at GMR posted about piston oilers so loose that they could be rocked back and forth using a needle nose pliers. That would definitely dump oil in the case.

As long as the crank is smooth I wouldn't think you'd gain by splitting cases.

As to the pump, that's a tough call and almost like discussing politics lol. I sumped my 120 once before installing Feuling and haven't had a problem since. That's a lot of $ I realize; I was at a loss myself and thought perhaps it would help, which it seems to have. I also run the oil at least half quart low.

[VDeuce]

Here's the GMR oiler vid, you may have to scroll down a bit to find the video. I suggest looking though some of the vids as you get a pretty good idea the issues these engines are having. The guys over on that other HD site with their head up their a** won't want to see these.

https://www.facebook.com/GMR-Performance-559176144113934/

[Sunny Jim]

Yes indeed. I am concerned at this gap between plate and crankcase. I suspect once the oil lines are pressurised, the would oil leaking back into the Cam chest.
I also recall ther$ was a casting fault in the lifter area on an early M8. Mine is a 2016 build.

[klammer76]

I follow GMR on FB also. He has found lose piston oilers on the M8 as VDeuce pointed out. I would reach out to GMR and have a talk.

[Rsw]

I follow GMR on FB also. He has found lose piston oilers on the M8 as VDeuce pointed out. I would reach out to GMR and have a talk.

Good advice there. Steve has seen a lot of the m8 issues

[VDeuce]

Yes indeed. I am concerned at this gap between plate and crankcase. I suspect once the oil lines are pressurised, the would oil leaking back into the Cam chest.
I also recall ther$ was a casting fault in the lifter area on an early M8. Mine is a 2016 build.

There is supposed to be a gap there; the HD revised pump backing plate with the seal is designed to close that gap. Its success is iffy at best with several reports of sumping bikes that were equipped with the seal. I realize you have the S&S.

As to the lifter bore issue, I saw that video as well; nasty problem. If you tear yours down, it should be evident when the lifter blocks are removed and the engine cranked.

[Sunny Jim]

VD, the seal on the HD pumps is on the back and seals up to the crank bearing. I have included  a photo. This is the oil feed into the engine where the Cam plate marries up to. It is this gap I am referring to. Unless I am missing something here, the Cam plate should fit flush against the engine case port as in the photos.

[Txwezl]

Yes indeed. I am concerned at this gap between plate and crankcase. I suspect once the oil lines are pressurised, the would oil leaking back into the Cam chest.
I also recall ther$ was a casting fault in the lifter area on an early M8. Mine is a 2016 build.

There is supposed to be a gap there; the HD revised pump backing plate with the seal is designed to close that gap. Its success is iffy at best with several reports of sumping bikes that were equipped with the seal. I realize you have the S&S.

As to the lifter bore issue, I saw that video as well; nasty problem. If you tear yours down, it should be evident when the lifter blocks are removed and the engine cranked.

The gap he's referring to is between the plate and the case not between the pump and the case. There is already an o ring on the case side so adding a groove and butting 2 o rings against each other will not solve his problem. At the least correct the piston jet gaskets, threads etc. You may have a plate that was machined wrong or it wasn't sitting flush with the case.

I had the same problem with the fueling OEM plate and the newest harley pump even after the piston jets were addressed. I ended up putting the original pump (early 2017) and stock plate back in and have not had any more sumping problems.

Like someone else said on here "Don't stick with a problem just because you spent money making it"

[Sunny Jim]

Tx, the photos I supplied point to the two holes that line up to each other. There is no O' ring on the case side. I struggle to think that this new SS set is faulty.
Having said that, after reading a comment from Durwood, I tighten the screws on the oilers as previously mentioned.

[FSG]

I tighten the screws on the oilers as previously mentioned.

you really need to take them out, remove the oiler, then run the screws back in to cut the thread deeper, then use a larger drill bit by itself to remove the surface mushroom around the hole so that the oiler will sit flat against the case

[Sunny Jim]

Further tests showed a 2-3 thou gap between SS Cam plate and crankcase port.
We plastigauged it.
The original camp plate had 1.5 thou difference.
The engine has completed approx 11000 km.
We measured the oil from CP sensor from the first sumping event. It was approx 750 ml.
The second event measured approx 800 ml and 300 ml from the Cam chest.
Where to from here?
Before we strip the engine again we are going to O,ring the original Cam plate at the main oil pressure port as previously discussed.

[Scotty]

Pulled apart the cam plate and  pump. Everything is in order except I noticed there was no evidence of the new ( and old ) camplate pressing hard up against the crank case casting . A straight edge across the holes indicates a gap of approx 2-4 thou.

Not having one in my hand to look at but hard to imagine why there would be a gap that large where oil is being pumped.

[Sunny Jim]

I agree Scotty. This is one of the earlier M8s. It's been a great bike except for this. Clearly the castings and mulling on these first models is substandard. The heads alone had 2-3 thought milling grooves in the face.