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-   -   Sportster Crankcase Pressure / Engine Breathing / Wetsumping and Mods (http://xlforum.net/forums/showthread.php?t=2073932)

Hippysmack 28th July 2019 20:28

Me thinks we've created a munster..:wonderlan

60Gunner 29th July 2019 16:29

I've tried to find any negative impact of moving the breathing and using the krankvent. There are none.
Temps are better than ever and so is scavenging.
If the stock setup is good enough for you, then by all means keep it. If you're trying to find a reason stock is better, you won't convince anyone that's done this. No one I'm aware of has ever gone back. I tried to find a reason to.

Hippysmack 29th July 2019 16:45

Go back through this thread.
I am not trying to prove any way is better or worse than the other.
I'll leave that to you and others.
I'm just gathering information about the title subjects (not just either way of venting).
There are way too many opinions that sway people based on someone's experience.
But there are many more considerations than just moving the vent location that are usually looked over.
Because a racer said so is no reason to go and re-engineer your entire street engine.
That seems to be a going trend (not speaking of you).

I may be the only one here that is trying to get a overall just of the entire system, not just the breathing system.

edit:
Just like you have to crack a few eggs to make an omelet, you have to refute some opinions to get to the guts of a subject.
That's when things get complicated as 'my opinion or my mod' is all you have to do and all your troubles go away.
History has proven that just ain't so.
I'm laying out subject matter that makes me go hhhhmmmm.
If what I'm presenting doesn't agree with anyone, I'm completely open to discussion.
I've already challenged some of my own opinions based off posts in this thread.
Discussion is a good thing. It helps us all learn more.

That's the purpose of this forum.
But refuting any other way of doing something hinders the learning process of all concerned.

bustert 29th July 2019 17:06

ye who stirs the pot last usually get the blame for how it tastes!

i like your diamond view of things. many facets to the total cut so who's to say this side looks better, turn it in the light, does it not change??
no, have not forgotten about the slack tube, been out of town and have two steels to put together.
i am going to pull the timing plug and make an adapter.

Hippysmack 29th July 2019 17:08

Quote:

Originally Posted by bustert (Post 5766148)
i am going to pull the timing plug and make an adapter.

Sounds good bustert.

Highly-Dangerous 29th July 2019 19:32

Quote:

Originally Posted by Hippysmack (Post 5765831)
Harley Davidson Motor Company. :D

Thank you!!! :D

Four Speed 29th July 2019 21:10

Bustert somewhere on here I saw an impressive Iron Head that had one of these reed valves mounted on hose from the timing plug and then to a catch tank:
https://www.heidentuning.com/xs650-s...te-detail.html

60Gunner 29th July 2019 21:26

I'm trying to find a reason one way works better than the other myself. A reason why it was moved to the heads from an engineering standpoint. I'd switch back in a heartbeat if there's one good reason to. Im playing the side of cam chest because other than 4 speed, no one else is really providing any info on how it works.
It's been suggested the stock breathers let a certain amount of air back in to keep pressure enough to help oil return. I think that's bs. Oil will drain just as well at atmosphere or even a slight vacuum. Maybe better. A clear cover would be nice. All I can say is my head temps seem to have gone down but I made several changes that could be part of the reason so it's hard to say how much is because of location or the better valve when compared to the failed stock ones. The fact I even had failing stock ones is an issue itself. Letting air in, any air, is not a good thing imo.

As for the krankvent imo it's already proven to be a better one way valve than the stock ones. Has anyone ever had one fail or need replacing? Idk but I highly doubt it. Does it close faster allowing less or no air back in? I think that's been shown. Perhaps not scientifically enough but it definitely works better at what it's supposed to do. Then there's the warping issue of the stock ones. I thought maybe they had been improved on since 04 but apparently not. Too bad. They could use improvement. Not sure where I saw metal ones that came apart.
Nevermind about the cosmetic aspect about the location. Perhaps some people like the dangling hoses. Who am I to pee in their oatmeal? ;p
Maybe pulling rocker covers to service or replace them is is an acceptable past time. Just not a favorite of mine. If I never had to pull them again it wouldn't hurt my feelings. I am once the riding season ends, however. Wedge is teaching me the finer points of home porting. Picked up a nice little angle grinder with bits I need at an estate sale down the street 2 weeks ago in fact.

I don't know what more can be done to prove or show one location is better than the other. At least not from a standpoint that matters much.
As a side note, it looks like I'm pulling that fitting. Turns out I have a chrome one. Found it digging thru my stuff. I think it came with my speedo housing setup. Had a few electrical connectors packaged with it and a couple hose clamps. Go figure.

Four Speed 29th July 2019 21:43

Quote:

Temps are better than ever and so is scavenging.
That is my conclusion as well 60Gunner. What seems unresolved is the claim on here that more crankcase compression assists scavenging;
I contend that it just increases aeration. Like you, I also see more oil in my oil tank after I fitted a proprietary one way valve.

Quote:

A reason why it was moved to the heads from an engineering standpoint.
I strongly suspect the mods HD did before the incoming Euro 2 etc emissions standards to reduce crankcase breathing were not to do with
performance but to keep hydrocarbon emissions to a minimum, as reflected by the decline in claimed power output. At the time Hydrocarbon
emission were cut back significantly, so recirculating the breathing inside the lubrication system would doubtless have helped but maybe this
lead to the subsequent increase in oil pump scavenging capacity.

Hippysmack 29th July 2019 23:53

Quote:

Originally Posted by Four Speed (Post 5766229)
What seems unresolved is the claim on here that more crankcase compression assists scavenging;

Crankcase pressure is ever changing on a running engine.
The whole variable crankcase pressure issue.

To quote exact wording from the FSMs:
2004 Hd FSM, page 3-11,
1998 HD FSM page 3-29,
1986-1990 HD FSM page 3-7,
1979-1985 HD FSM page 3-7:
Oil flow to the pump is accomplished by the scavenging affect of the pump and by the pressure created by the downstroke of the pistons .

So we know downstroke (positive pressure) is a normal productive part of the scavenging system.
The good books tell us so.
Hammer Performance also suggests a vacuum on the system hurts scavenging.
We've seen the balloon test that shows during idle and normal riding, in/out pressure is relatively stable up to 3500 RPM ish per DK Custom.
(variables unknown of course)

What am I missing?
The extra blowby shouldn't be present until you hit the high speed / high RPM.
That's the extra air pressure that adds to positive on downstroke.
But an engine can wet sump due to quick on/offs as well.
Quickly adds more oil to the sump and then the off throttle doesn't allow as fast of scavenge with the quick reverse affect of CC pressure.

Try the balloon test and tell us how your engine reacts.
I can't on mine until I run vent lines.
So far I've kind of been on defense trying to learn of what you've been saying.
But now that I'm more up to speed, I can't understand your reasoning.
It was presented in the wet sumping thread that higher crankcase pressure aides in scavenging but it hinders crankcase pressure as it picks up more oil in suspension as well.
It makes the air/oil mist thicker.
Everything, including Hammer Perf, suggests the thicker air/oil mist is what overcomes the breather valve to puke oil out the vent
There is nothing to suggest, other than what you've been saying, that higher crankcase pressure makes scavenge oil more bubbly.
So I ask, where did you get that information from?
If you'll cite it, I'll research it.
There are several conditions as to what happens to make aeration in the oil scavenge return.
The main reason is that the oil pump scavenge gerotors are bigger than the feed gerotors.
Doing the math, aeration is most prevalent due to the oil pump scavenge side working too good.
Doesn't that make sense?
I've read from IHs to Evos, all year gerotor pumps that the oil, when viewing inside the oil tank, will return and then not return and that should be the cycle by default of the math.

During the time that the oil pump has just pumped what was available at the scavenge port and is waiting for downstroke to deliver more oil to the port, higher crankcase pressure is wanted to deliver that oil.
If there is only a slight push pull going on, the pump could cavitate due to no oil to the inlet especially during several quick on/off throttles where CC pressure is the most turbulent and can pick up the most oil during this time.

dieselvette 30th July 2019 00:00

Quote:

Originally Posted by Hippysmack (Post 5766145)
'my opinion or my mod' is all you have to do and all your troubles go away.
History has proven that just ain't so.

I think it would be advantageous to ask some of the riders who put lots and lots of miles on their bikes and see what they have or haven't done. (Maybe you've done that already?). I don't know all of them but I could name a few if you need.

Hippysmack 30th July 2019 00:09

Well, with all respect, I've spent years so far doing nothing but reading XLF threads of what others have done.
It's disheartening to read 'this is what I've done and this is what you must do" when there hasn't been much actual testing other than the fact "it worked for me".
That is not evidence that it'll work for the next guy with all the different engine configurations out there.

I've been working my ass off trying to learn as much as I can.
But I don't have high lift cams and damn the torpedo compression.
Neither does a lot of folks who "must do this".

See my point?

dieselvette 30th July 2019 00:16

Quote:

Originally Posted by Hippysmack (Post 5766274)
There is nothing to suggest, other than what you've been saying, that higher crankcase pressure makes scavenge oil more bubbly.

It is a fact of physics, that smaller bubbles, if small enough, will take a lot more time to come out of solution (they float to the top very much slower). If a given scenario is making tiny bubbles then you could have foamy oil or some kind of compounding problem.

One thing that would make bubbles smaller, is higher pressure. As the pressure is relieved, the bubbles would grow again and come out easier.

Any bubbles would also affect the perceived oil level.

There are actually formulas to figure out what size bubble does what in a given fluid. Thats getting way way way in the weeds though. My gut tells me that we're not dealing with significant pressure changes enough to make a measurable difference. But, I'm just throwing it out there.

Hippysmack 30th July 2019 00:32

Yeah my schooling didn't go that far.
But I do know that air and oil don't mix.
It's the churning when there is too much oil in the sump that allows more oil to ring around the wheels and cause froth in the tank.

edit:
But when this happens, it drastically drops the RPM of the engine.
If you're pump isn't keeping up, you're not going as fast either.

I also contend that blowby or added air on upstroke will yield a higher dense air/oil mix, as in the case of my RPM drop with the oil cap off.
When suspended oil gets thrown back to the sump faster than the oil pump is receiving more oil from downstroke. is when the tiny bubbles get into the scavenge port.

My contention is a lower pressure in the sump area allows this to happen.
If there is more positive in the sump, the suspended oil thrown down has a longer road to the scavenge port and more time to separate or get picked back up.
We speak of this in terms of a positive slow start and stop of the pistons but everything is happening quite quickly in the crankcase.

Hippysmack 30th July 2019 00:42

Credits for this article
 
I've left the credits out for a reason.
I didn't want to name drop but rather discuss the issues without he said / she saids, which does taint a good discussion.

But now I realize it appears that the information was made up in my head.
The origins of this thread are a culmination of many members here that do have a lot more schooling and experience than me.

Four Speed, you bring up some good questions but seem to back off conversation with me.
That's fine, I just want to clear up that I'm both following other's lead as well as concluding on my own.
Information given to someone is useless without them receiving it.

So here is a list of all the folks who have their thoughts and endeavors represented in this thread.

1)
Deimus of the XLFORUM http://xlforum.net/forums/showthread.php?t=73243&page=4

2) , 3) , 4) , 7) , 99)
Dr Dick of the XLFORUM http://xlforum.net/forums/showthread.php?t=1204854

5)
cjburr of the XLFORUM http://xlforum.net/forums/showthread.php?t=73243&page=3

6) , 23)
aswracing of the XLFORUM http://xlforum.net/forums/showthread...=59421&page=27

8) , 14) , 15) , 16) , 17) , 18) , 19) , 20) , 28) , 29) , 40) , 41) , 42) , 43) , 84) , 110)
drawing by Hippysmack

9) , 30) , 63)
photo by Hippysmack

10)
Dr Dick of the XLFORUM http://xlforum.net/forums/showthread...1204854&page=4

11)
Dr Dick of the XLFORUM http://xlforum.net/forums/showthread...1204854&page=3

12)
https://www.setra.com/blog/vacuum-pr...you-measure-it

13)
https://www.dekkervacuum.com/resourc...hat-is-vacuum/

21) , 22)
maru of the XLFORUM http://xlforum.net/forums/showthread...d+valve&page=8

24)
Jorgen of the XLFORUM http://xlforum.net/forums/showthread...d+valve&page=9

25)
aswracing oftheXLFORUM http://xlforum.net/forums/showthread...1946516&page=4

26) , 50) , 54)
bunny32 of the XLFORUM http://xlforum.net/forums/showthread.php?t=67658&page=2

27)
bunny32 of the XLFORUM http://xlforum.net/forums/showthread.php?t=67658&page=6

31) , 74) , 96)
aswracing of the XLFORUM http://xlforum.net/forums/showthread...d+valve&page=6

32)
thecarfarmer of the XLFORUM http://xlforum.net/forums/showthread...1204854&page=4

33) , 34) , 35)
aswracing of the XLFORUM http://xlforum.net/forums/showthread.php?t=15705

36)
aswracing of the XLFORUM http://xlforum.net/forums/showthread.php?t=15705&page=2

37)
Deimus of the XLFORUM http://xlforum.net/forums/showthread.php?t=67658&page=3

38) , 48) , 49) , 98)
aswracing of the XLFORUM http://xlforum.net/forums/showthread...ume#post110375

39)
bunny32 of the XLFORUM http://xlforum.net/forums/showthread.php?t=67658&page=3

44)
photo by Jörgen http://xlforum.net/forums/showthread.php?t=75740&page=9

45) , 46)
maru of the XLFORUM http://xlforum.net/forums/showthread...10#post3780510

47) , 55)
Hippysmack of the XLFORUM http://xlforum.net/forums/showthread...23#post5757523

51) , 104)
Jorgen of the XLFORUM http://xlforum.net/forums/showthread...d+valve&page=7

52) , 53) , 57) , 58) , 59) , 67)
Hopper of the XLFORUM http://xlforum.net/forums/showthread...chest+breather

56)
1960 HD FSM pg 3a-15

60)
HD Service Bulletin #M-848 dated April 9, 1982

61) , 64)
FoxsterUK of the XLFORUM http://xlforum.net/forums/showthread...ht=wet+sumping

62)
photo by Phillober of the XLFORUM, labeled by Hippysmack http://xlforum.net/forums/showthread...64#post3345764

65)
photo by DK Custom of the XLFORUM http://xlforum.net/forums/showthread...582019&page=11

66)
photos by Bored now of the XLFORUM, annotated by Hippysmack http://xlforum.net/forums/showthread...87#post5761087

68)
bunny32 of the XLFORUM http://xlforum.net/forums/showthread.php?t=15705&page=2

69)
Deimus of the XLFORUM http://xlforum.net/forums/showthread...=67658&page=18

70)
electronbee of the XLFORUM http://xlforum.net/forums/showthread...+valve&page=10

71)
photo by electronbee of the XLFORUM http://xlforum.net/forums/showthread...+valve&page=10

72)
photo by Bluto of the XLFORUM http://xlforum.net/forums/showthread...90#post5761290

73)
Photo by goblin_dust of the XLFORUM http://xlforum.net/forums/showthread...umping&page=23

75)
aswracing of the XLFORUM http://xlforum.net/forums/showthread.php?t=20871

76)
chart by aswracing of the XLFORUM http://xlforum.net/forums/showthread.php?t=20871&page=2

77) , 94)
aswracing of the XLFORUM http://xlforum.net/forums/showthread...1946516&page=4

78) , 79) , 80)
photo by aswracing of the XLFORUM http://xlforum.net/forums/showthread...1946516&page=4

81) , 82) , 83)
chart by aswracing of the XLFORUM http://xlforum.net/forums/showthread...1946516&page=4

85)
NRHS Sales of the XLFORUM http://xlforum.net/forums/showthread...+guide&page=31

86)
jrclark19 of the XLFORUM http://xlforum.net/forums/showthread...+guide&page=31

87)
http://xlforum.net/forums/showthread...+guide&page=31

88) , 89) , 90) , 91) , 92) , 93)
photo by cjburr of the XLFORUM http://xlforum.net/forums/showthread...+guide&page=31

95)
maru of theXLFORUM http://xlforum.net/forums/showthread...d+valve&page=6

97)
chevelle of the XLFORUM http://xlforum.net/forums/showthread...1204854&page=3

100) , 102)
Dr Dick of the XLFORUM http://xlforum.net/forums/showthread...1204854&page=2

101)
maru of the XLFORUM http://xlforum.net/forums/showthread...d+valve&page=7

103)
IronMick of the XLFORUM http://xlforum.net/forums/showthread...1332902&page=3

105)
Deimus of the XLFORUM http://xlforum.net/forums/showthread...107#post841107

106)
Gord of hpacademy.com https://www.hpacademy.com/forum/off-...y-sump-systems

107)
dieselvette of the XLFORUM http://xlforum.net/forums/showthread...107#post841107

108)
photo by WestJC7745 of the XLFORUM http://xlforum.net/forums/showthread.php?t=1971672

109)
photo by meherdad_it of the XLFORUM http://xlforum.net/forums/showthread...hreadid=944843

111)
Deimus of the XLFORUM http://xlforum.net/forums/showthread.php?t=87313

112)
Hippysmack of the XLFORUM http://xlforum.net/forums/showthread...971026&page=28

113)
photos by cootertwo of the XLFORUM http://xlforum.net/forums/showthread...hreadid=148936

114)
bustert of the XLFORUM http://xlforum.net/forums/showthread...el#post5750657

115)
Toejam503 of the XLFORUM http://xlforum.net/forums/showthread...el#post5750657

116)
Deimus of the XLFORUM http://xlforum.net/forums/showthread...umping&page=21

117)
Hippysmack of the XLFORUM http://xlforum.net/forums/showthread...94#post5763694

118)
ryder rick of the XLFORUM http://xlforum.net/forums/showthread...1904589&page=4

119) , 124)
https://www.gzmotorsports.com/why-use-vacuum-pump.html

120) , 121) , 122) , 123)
https://www.dragzine.com/tech-storie...en-horsepower/

60Gunner 30th July 2019 01:04

I'm often at a loss to explain why I'm seeing what I'm seeing. I can only report on what I'm seeing and often speculate as to the cause or reason for what I'm seeing.
What I'm seeing has been nothing but positive. No air bubbles or foaming in the tank and a slightly higher oil level in the tank. Lower head temps also seem to be a result.
The technical reason this occurred is probably more than my limited knowledge can explain. I DO know it's a positive result of one or more of 3 things I did. A better one way valve that defintely lowers or eliminates positive crankcase pressure, moving where this pressure exits, and installing a pump with better scavenging. Perhaps it's the combination of these that's made it work so well. IDK.
I'm not suggesting anyone do this based solely off my experience.

So far so good on the rocker cover leaks as well.

bustert 30th July 2019 03:58

i find no fault with the stock system, working as intended. as before, i route the vent diff but i have no issues with the bag. maybe with some more miles, things could change but for now, it'll take all the flogging i give it.
perhaps phsyco-somatic? like the little train going up the hill, i think i can, i think i can when in reality, he could all along!!!

Hippysmack 30th July 2019 04:26

We know that the more air that is pulled into the engine, the higher the density of oil suspension = puking.
This is with an unlimited supply of air but intake thereof is based soley on the duration of upstroke.

It's interesting that the krankvent comes factory with an air gap (the spacer).
The design should allow a controlled amount of air in behind the closing of the valve.
This controlled amount of intake will delay the affect of upstroke.
As in it will take a slight longer to build vacuum.
Thus net vacuum produced will be less.
The less the vacuum at the point of downstroke, the higher the affect of positive pressure through downstroke.

A fast closing valve simply allows more vacuum to be produced on upstroke.
Thus lowering positive pressure on downstroke giving better ring seal.
But better ring seal yields less blowby to help with scavenging.

So Gunner I'd deduce that your engine sounds better due to better ring seal from the lower controlled intake of air during breather valve closing.
You can install a clear return line temporary to actually see what's coming out of the sump and into the tank to check aeration.

I forgot ask.
What caused this?
Quote:

Originally Posted by 60Gunner (Post 5763761)
Well maybe it was the cover after all.
http://i65.tinypic.com/5n6b76.jpg


60Gunner 30th July 2019 05:35

Quote:

Originally Posted by Hippysmack (Post 5766319)
We know that the more air that is pulled into the engine, the higher the density of oil suspension = puking.
This is with an unlimited supply of air but intake thereof is based soley on the duration of upstroke.

It's interesting that the krankvent comes factory with an air gap (the spacer).
The design should allow a controlled amount of air in behind the closing of the valve.
This controlled amount of intake will delay the affect of upstroke.
As in it will take a slight longer to build vacuum.
Thus net vacuum produced will be less.
The less the vacuum at the point of downstroke, the higher the affect of positive pressure through downstroke.

A fast closing valve simply allows more vacuum to be produced on upstroke.
Thus lowering positive pressure on downstroke giving better ring seal.
But better ring seal yields less blowby to help with scavenging.

So Gunner I'd deduce that your engine sounds better due to better ring seal from the lower controlled intake of air during breather valve closing.
You can install a clear return line temporary to actually see what's coming out of the sump and into the tank to check aeration.

I forgot ask.
What caused this?

Idk. You tell me. Every time I pulled a cover to fix a leak, I found something like that. Obvious damage that explained the leak. I assumed it was too much crankcase pressure. That got me looking into the breathers and found they weren't sealing out air for shit. And here we are.

Four Speed 30th July 2019 10:34

Morning Hippysmack, don't feel rejected, we are separated by an Ocean and many time zones. And as I told you, I also am in the middle of major building work.

Quote:

So we know downstroke (positive pressure) is a normal productive part of the scavenging system. The good books tell us so.
Surely, that depends on the pressures involved. If there is a sufficient negative crankcase pressure it could overcome the scavenging but Harleys don't
run like that. Because of the piston configuration oil a Harley they will have alternating positive and negative pressure similar to a single cylinder engine.
Take your scenario; as the pistons fall they compress the volume of air contained in the crankcase which contains oil mist and this air has to go somewhere.
If the engine breather does not vent these pressure spikes, the air is likely to find its way out of the engine via the scavenging which increases aeration.
So you end up with proportionally more froth in the oil tank and hence less oil. This is a simplified, as the movement of air will be effected by blowby,
revs harmonics, how airtight the engine is and scavenge capacity. What I think HD did was to progressively ensure that the air oil mist could be recirculated
in the lubrication system to minimise hydrocarbon emissions, albeit with a significant loss of BHP.

Have read of this summary for instance:
https://www.enginelabs.com/tech-stor...d-air-control/

Here is the Hayden patent (which also explains why they have the ring on their valve).
https://patents.google.com/patent/US5881686A/en

As I explained, I don't think the 'ballon' test is a good method to test air flow as it introduces too much back pressure for the PCV. You would need a flow gauge which I don't have.

Here is a pragmatic approach: if you get excess oil mist down your leg, gaskets that are oil misting or notice that the oil tank is filled with foam, try renewing the umbrella
valves (not easy on an the 86-90 engine) or replace them with a proprietary valve and see if it helps; like 60Gunner and I did.

It's all good.

Hippysmack 30th July 2019 15:24

Quote:

Originally Posted by 60Gunner (Post 5766321)
Idk. You tell me. Every time I pulled a cover to fix a leak, I found something like that. Obvious damage that explained the leak. I assumed it was too much crankcase pressure. That got me looking into the breathers and found they weren't sealing out air for shit. And here we are.

I see that you've had several problems with gaskets but I was wondering if installation or a bad run of gaskets had been ruled out as I hadn't remembered you finalizing that.
So I assume you're thinking CC pressure split that gasket like that?
If so, that was a pretty violent environment your engine was in.

I have read other accounts of weeping gaskets etc. due to CC pressure but I haven't seen the actual carnage.

60Gunner 30th July 2019 16:06

I paid very close attention to installation. Especially after the first time. Making sure it didn't get twisted or pinched. Ensuring the alignment of the covers, etc. It wouldn't leak initially, but within a few hundred miles it would leak and leak pretty good. The damage was always at or very near the openings in the inside lip that forms the channel in the rocker boxes that the gasket sits in. A place of less resistance for the pressure to get directly to the gasket. Combined with the excess heat caused by the pistons working harder because of the excess pressure also weakens the rubber. When I pulled one warm, barely cooled enough to touch the covers, the gaskets were noticeably flimsy. This made them more susceptible to the damage.
That's my theory anyway. I think it's a fairly sound one.

From what I could tell, the stock umbrella might as well not have even been there. I blew pretty hard into one and air just continued out the other other until I quit blowing. That's failure at its finest. Why? I can only assume it's because they are cheap and flimsy compared to the one in the krankvent.
I just glad I figured out they were bad before putting too many miles on my build and I never went on any longer rides.
I'm sure I'll clean out the mess inside caused by this in a short time.
So like I've said from the beginning, run the stock ones if you think they're up to the task. I'm just glad I found a better replacement for my motor. One that can be easily inspected for failure and cleaned if necessary. And one I think does a better job than even a brand new stock one.
We replace stock parts with better aftermarket alternatives all the time. I'm not sure why the thought that these might not be the best for the job is so foreign to some.

Toejam503 30th July 2019 16:21

I was wondering, Did you look at the surfaces, where the gasket goes, and see if there may be any sharp edges or nicks that could "cut" the gasket?

60Gunner 30th July 2019 16:43

Quote:

Originally Posted by Toejam503 (Post 5766414)
I was wondering, Did you look at the surfaces, where the gasket goes, and see if there may be any sharp edges or nicks that could "cut" the gasket?

Yes I did. I even lightly sanded with 1000 grit before the last install that failed. Altho it's hard to do that channel on the lowers, I didn't see anything that would cause this. Also remember they didnt leak before. All the surfaces were thoroughly cleaned as well.
Alex at Hammer is having a similar issue with rocker cover leaks. He's done a thorough lapping after discovering some warpage. He's still weeping oil.

harley506d 30th July 2019 17:03

Originally Posted by Hippysmack View Post
That looks nice and tidy.
I have a question about the bend in the line before the filter.
What, if at all, have you noticed in the line at that bend?

I'm thinking oil / condensation could settle there even if it doesn't run up to the filter.
I guess better put, ever pulled the filter to inspect the line near the bend?

I like the 'Y' down low instead of the horseshoe up with only one side running down for the same reason.

Hippysmack,
Sorry, i forgot to follow up a little on this.
I had another check to see what was in the pipe and there was the tiniest amount of oil in the pipe. Just a tiny drop came out. No sign of any moisture this time. Washed the filter out, but it was still as clean as new really.
Stock motor/breather bolts/air filter/exhaust.
There was a pic of a gunge'd up breather bolt on here somewhere, just wondering if this would still happen with a fully syn' oil? Or does this happen with mineral oils only?
Another pic showing the plug cap boots etc.

https://i.ibb.co/Zg4rLvf/air-box-001.jpg

60Gunner 30th July 2019 17:14

Mine were dry too when I sucking a shit ton of air back in. Have you checked to verify the umbrellas are even functioning? I can literally feel mine pulse now. Pulses out but not back in.

I'm going to check the better ring seal thing with a compression test later after I ride. If it's noticeably better, even 5lbs. higher, that's a good indication of better ring seal.

Hippysmack 30th July 2019 17:53

Quote:

Originally Posted by harley506d (Post 5766424)
I had another check to see what was in the pipe and there was the tiniest amount of oil in the pipe. Just a tiny drop came out. No sign of any moisture this time. Washed the filter out, but it was still as clean as new really.
Stock motor/breather bolts/air filter/exhaust.
There was a pic of a gunge'd up breather bolt on here somewhere, just wondering if this would still happen with a fully syn' oil? Or does this happen with mineral oils only?


That's a good close-up.
Thanks for that.
The connector to the boots special or can I get it anywhere?

That's good to hear with the line being of minimal film at best.
I'd think the true PAOs would be less likely to emulsify in the line due to their resistance to emulsifying.

But true PAOs are hard to come by.
Most 'synthetics' are really just finer quality dino oil.
So it may vary to a degree but the base oil is the same between them.
Used oil will break down to different degrees and may even show more of there similarities when worn than when new.
So, I wouldn't really think that would change the emulsion much in form.
Testing may show otherwise though.

Hippysmack 30th July 2019 17:57

Quote:

Originally Posted by 60Gunner (Post 5766428)
I'm going to check the better ring seal thing with a compression test later after I ride. If it's noticeably better, even 5lbs. higher, that's a good indication of better ring seal.

I'd like to know that also.

Hippysmack 30th July 2019 18:00

Quote:

Originally Posted by Four Speed (Post 5766334)
Morning Hippysmack, don't feel rejected,

OK,
That made me giggle.......... a lot. :laugh

I'm going over the links you posted.
Thanks for those.
I'll make some notes on them.

Four Speed 30th July 2019 18:30

You did invite it with this comment :) :
Quote:

Four Speed, you bring up some good questions but seem to back off conversation with me.

Quote:

He's still weeping oil.
If the components are warped beyond what the gasket can accommodate then you will probably see a proper leak i.e. dripping oil.
If it caused by excess crankcase compression on an otherwise intact gasket then you are more likely to see oil 'misting' around several gaskets.


Quote:

Originally Posted by 60Gunner View Post
I'm going to check the better ring seal thing with a compression test later after I ride. If it's noticeably better, even 5lbs. higher, that's a good indication of better ring seal.
That should be interesting. BTW 60Gunner did you see the link to the Hayden patent?

Regarding the oil/water emulsion: it is probably due to short trips and water not evaporating out of the engine. However, if my contention is correct
that more recent engines recirculate more of the hydrocarbons then that may concomitantly reduce the ability to remove water vapour.

60Gunner 30th July 2019 20:16

Yeah I read that. Seems its expired.
My take on the ring allowing a small amount back in is as much vacuum that will still allow good scavenging. The more vacuum the better. I ground that ring down somewhat allowing little to no air back in increasing vacuum. Probably not by much but...

I did a compression test and while it is slightly higher, 5lbs, the video in the link below shows why it cannot be trusted to give a proper reading. Hammer Dan told me the same thing. Everyone they've tested was off by by roughly 20lbs light. This guy suggests it's more and another guy actually tested it on a small engine. It came up with under 30lbs while a known good gauge was at 60lbs.
So while it's slightly higher, I think it's even more.

https://youtu.be/q1H7550B48I

Here's another review.

https://youtu.be/4ke8t5L1EPg

harley506d 30th July 2019 20:48

"The connector to the boots special or can I get it anywhere?"


I bought all the bits off ebay. If i remember rightly, it was all 8mm. 2 straights and 1 "T".
Caps were for some old Brit car, but any with soft rubber should be fine.
The innards obviously removed and the part that fits over the plug cut down some. "O" ring on breather bolt removed.Cut the air filter sleeves that normally slide onto the breather bolts to leave about a 1/8" stub, and that should seal against the plug cap rubber when filter is tightened down.

dieselvette 30th July 2019 22:11

Quote:

Originally Posted by 60Gunner (Post 5766428)
I'm going to check the better ring seal thing with a compression test later after I ride. If it's noticeably better, even 5lbs. higher, that's a good indication of better ring seal.

That's an really good idea.

If you dare, you could do this test with vs without the Krankvent installed.

dieselvette 30th July 2019 22:31

I have a theory about the "purposely leaky" check valves (stock has the "oil drain hole" , krankvent has the "ring" that can be modded) --- this could be simply a liability/safety concern.

While parked, there is the potential for pressure/vacuum buildup in the cc. With the crankcakse totally sealed, and potential for unburnt fuel vapors to exist in the CC (ever drained the oil on a car that wouldn't start, and found it full of gas?). Or, consider if there is fuel above the rings that could be drawn down if the cc is at vacuum.

The intentional "leak" at the check valve(s) allows the cc to stay equal to atmosphere when the engine isn't running. In stock, working form it apparently has little/no effect on the operation while running, and prevents oil from coming out.

Krankvent designers apparently believe the intentional leak has little effect, too, and if connected at the heads while leaving the stock umbrella assy in place, you would also retain the oil catching feature.

Or, maybe it's not a safety issue but a different reason.

Tomcatt 30th July 2019 22:39

Quote:

Originally Posted by dieselvette (Post 5766495)
I have a theory about the "purposely leaky" check valves (stock has the "oil drain hole" , krankvent has the "ring" that can be modded) --- this could be simply a liability/safety concern.

Or it made a generic "umbrella" patent-able because it was then not just a generic umbrella.

Four Speed 30th July 2019 23:00

I'm with Tomcatt on this. Umbrella valves typically relax when there is no flow and deform in the direction of pulses when there is.
A reed valve may be slightly different as most are held shut until the reed flexes due to an air pulse.

Four Speed 30th July 2019 23:18

Quote:

I did a compression test and while it is slightly higher, 5lbs
Interesting find 60Gunner! :)

Yes, some gauges are garbage. Mine has a valve in the adapter head which is good, but it is 14mm,
so I have to add a reducing adapter which adds volume; not so good. But even if your gauge is out,
you are using the same gauge, so if there is a measurable difference, it should be reproducible with
a more accurate gauge. You could take the average of three tests to see what the test-retest variability
is and then do the same without the Krank vent.

60Gunner 30th July 2019 23:40

It goes as far up as it going to on the 1 stroke and that's it. Checked the one for loan at O'Reillys. Same thing. I'd like to know what my compression actually is but I don't want to spend the money on a good tester to use once.

Hippysmack 31st July 2019 01:29

I agree the balloon is not an accurate test. But there is merit to the reaction of the balloon.
Heating thin rubber with hot (compress-able) air and asking it to be consistent is not very scientific.
But that is the premise that DK Custom is using to sell their product.
It would be better for them to include the non-scientific nature of the testing so as to not make us feel cheated with the results.
I haven't received anything from the request that I posted on their thread that mentioned the info for the balloon testing.
No offense guys, but this is the part about cracking a few eggs I mentioned earlier.....

I made some notes from the Engine Labs article.
While informative, I'm still working on the angle all this bears on a Sportster engine.
In all due respect, it made me even more against adding a vacuum pump in a Sportster engine.
It is also written by instrument to sell products to you.
But let's break down some of the information that relates.


PCV Valve

All internal combustion engines generate some type of crankcase pressure in the form of blow-by.
Blow-by is combustion gasses that escape past the piston rings.
In the early 1960s, General Motors identified crankcase gasses as a source of hydrocarbon emissions.
They developed the PCV valve in an effort to help curb these emissions.
This was the first real emissions control device placed on a vehicle.
While most of us who are performance enthusiasts will roll our eyes when emissions controls are even mentioned,
GM actually did the performance world a favor here.
Not only does a properly operating PCV system reduce the overall emissions output of a vehicle while at the same time not sacrificing horsepower,
It also has other benefits. It improves gasket seal, and prolongs gasket life by reducing the blow-by effect.
Further, it also helps reduce the amount of oil an engine consumes through the combustion cycle, or loses due to leaking seals.


The PCV in our engines has a bigger role than emissions.
The engines are designed to incorporate a PCV.
So a PCV valve in our engines can be viewed the same as a piston or a carburetor.
The engine was designed with it being an integral part of the system.
An umbrella valve is a form of PCV just as the krankvent with or without a reed valve (which is another form of PCV).


Oil Separator (Catch Can)

Not long ago Moroso released a video of one of their air-oil separator systems in action.
The separator was placed in-line with the PCV system on a stock Cadillac CTS-V.
The car had only 24,000 miles on it, and the test drive lasted about thirty minutes.
They included both hard acceleration, and just general cruising like the car would likely see in regular use.
You can see several puffs of oil and water vapor enter the clear container that was substituted in place of the aluminum one for this video.
This is further evidence that the factory PCV system on a high-performance, unmodified engine, with low mileage is inadequate.
The car’s owner states that after about a week of regular driving there’s typically about 3/4" of oil in the separator.
While this may not sound like a lot, consider how much oil that is over the course of an oil change interval, a period of twelve to sixteen weeks on average.
So every twelve weeks the separator would accumulate about eight inches of oil in its reservoir.
The actual volume would vary based on the dimensions of the separator, but that is definitely a substantial amount of engine oil.
Moroso’s Air-Oil Separators plumb directly into the car’s PCV system.
Using mesh filter media, they capture the majority of the engine oil that escapes the crankcase and is normally sent back to the engine through the intake.
“Removing this oil mist before it re-enters the engine reduces detonation, and deposits on the intake track, including the valves themselves,”
Most of the separators have a total volume of just under a quart of oil and have a drain valve to allow the collected oil to be cleanly and easily drained into another container.
Moroso offers these separators in both a universal style and direct fit for multiple vehicle specific applications.
They also offer Air-Oil separators for dry sump and racing applications.
These separators work much the same way that their street systems do, however they are designed for car’s running at the track rather than cars that are street driven on a regular basis. These systems do not plumb into the factory PCV system, instead they are stand alone separators.


Catch cans are in use on Sportsters all over.
I, for one, am concerned of the back pressure from long oil lines, routing and fittings past the breather valve.
Anyone that is trying to lower CC pressure could in fact raise it instead with a bunch of restrictions in the vent path.
So you are not always helping with the intended course of action.
Sometimes these things may hinder more than help.
Again, there needs to be testing involved.


Wet Sumping

In a wet sump system, high Gs in racing / cornering can cause oil to move away from from the pump inlet.
In a dry sump system, the oil still returns to the pan just like a traditional wet sump system.
However, it’s immediately pulled away by the scavenge stage of the external oil pump.
With a dry sump, the migration of oil in the pan under high-g loads is negated since the oil is collected almost as soon as it returns to the pan.
This rapid collection also helps to ensure that the pickup is not starved for oil under such conditions that would cause the engine to suffer a drop in pressure or total lack of lubrication.


I've also read on the forum where that was discussed.
A theory was made that the inertia will keep the oil in position in a motorcycle during cornering.
I haven't enough info to weigh in on that.
In a wet sump engine, the oil in the pan can sway, I agree.
But with the oil tank being separate in a dry sump, the small sump area doesn't allow much variance to sway I'd think.
And positive pressure is still directiing the flow direction.
But under the right conditions, who knows?

In our engines, oil is not immediately pulled away by the scavenge pump.
The oil in the sump has to travel up hill mainly by suction to get to the pump where the gerotors force oil back to the tank.
There is a suction created by hydraulic seal. Check.
But the oil flow to the return gerotors is dependant on how much suction the pump can muster from the scavenge port.
Positive pressure is suppose to keep oil to the scavenge port.

-----------

Vacuum

Sometime in the late 1970s to early 1980s professional engine builders discovered that applying vacuum to the crankcase would in-fact improve engine performance.
Wade Moon, from Peterson Fluid Systems, tells us, “Twelve to fourteen inches of vacuum is a pretty safe area to be at.”
Vacuum applied at around twelve to fourteen inches of mercury (HG) will improve ring seal, allowing lower tension rings to be utilized.

This also improves oil scavenging, cavitation, and windage, getting oil away from moving parts and back to the pickup faster.
Moon went on to tell us “We have had customers tell us they have seen a 35 hp increase pulling fourteen inches of vacuum.”
This makes running a vacuum pump on a racing engine that much more appealing.

Moon also pointed out two other key areas to keep in mind when selecting a vacuum pump.
Block material is one; an aluminum block can be harder to pull vacuum in.
At higher RPM the cylinder walls actually move a little, breaking ring seal which has an impact on overall vacuum.
Fuel type is the other area to consider; gasoline or methanol.
Methanol powered engines typically have greater blow-by, requiring a larger pump to generate and maintain proper vacuum.

Above 14-15 inches of vacuum, you pull too much oil away from the wristpins and cylinder walls,” said Meier.
In these cases, the higher end engines will employ measures such as oil squirters to spray the wrist pins, as well as special camshaft squirters, and even other provisions to oil the rocker arms and valvetrain.
All of this must be taken into account when running higher levels of vacuum.


They are discussing applying vacuum to a V-8 engine giving 12-14 inches of mercury (HG).
How much vacuum is better or too much for a Sportster 45 V-2 engine?


Dry Sumps and Vacuum

With dry sump systems vacuum is applied to the crankcase whenever a scavenge stage is not drawing oil from the system.
This means that there is not usually a need for a separate vacuum pump in a dry sump system.
“All dry sump pump scavenge stages will move oil and air.
Not all scavenge stages are pumping oil all the time, so if there is no oil then they move air,” says Moon.
How much vacuum is determined by the pulley selection,
design of the pump,
number of stages,
and the amount of time each stage spends scavenging oil compared to the time it spends creating vacuum.
This means that in a dry sump setup, vacuum must be monitored appropriately to ensure that it’s being applied properly throughout the engine’s operating range.


The first line doesn't seem to apply to a Harley.
This part suggests vacuum helps scavenging.
I'd have to have a complete understanding of a dry sump auto system before commenting on the advantages in that in an auto.

But this is not what Harley Davidson Motor Company says about their engines.
Two different systems.
Air vacuum being pulled up on upstroke pulls oil away from the scavenge port.
We use scavenging and POSITIVE air pressure to return oil.
The FSM specifically says "On piston downstroke" which is not a vacuum condition.
Vacuum is applied on upstroke but the gerotors are trying to scavenge during all strokes.

Now I can see the pump continually trying to scavenge.
On downstroke, there is oil at the inlet to be scavenged.
On upstroke, the oil is pulled away from the inlet but the same time the pump is sucking out what's in the passage.
Then downstroke gives oil back to the passage.
The pump still has hydraulic seal as the expended oil still leaves a film inside the pump cavity.
And that is helped also on 98-up engines with the cam chest port.
It still receives oil even on upstroke to help keep the hydraulic seal in place.

I agree as we have discussed before, the pump will move oil and air.
Not all scavenge stages are pumping oil all the time, so if there is no oil then they move air. ??????
We're not using different scavenging stages.
It's just one set of gerotors with either one or two inlets depending on year model.
They seem to be talking multi-stage oil pumps which we don't have.

This suggests that our oil pumps are actually creating air vacuum.
Wouldn't that also need a separate system to pump into than back to the cam chest positive pressure to actually create a vacuum from the pump?
(as in removing the vent line from the oil tank?).
The positive displacement pump requires a hydraulic seal to create suction at all which means it can't suck air at the same force as oil.
It can move air but not with force as it does the oil.

Vacuum pumps are spec'd for automobiles, not motorcycles.
GZ MotorSports offers many type vacuum pumps rating from 400 HP up to 2000+ HP.
You will not even get close to that range of needing a vacuum pump in a Sportster.
In fact, with the cheaply made aluminum case, a vacuum pump could actually destroy a Sportster engine according to this article.

You can use something much smaller as in a vacuum pump made for auto brake systems as bustert has mentioned before.
But even then, it needs to be monitored.


In road racing applications, and some drag racing instances where there is frequent throttle fluctuation from changing conditions or “pedaling” the throttle,
There may also be a need for a pop-off valve to help relieve built up pressure.
Under these circumstances, the engine can actually go from a vacuum situation to a positive pressure situation.
Generally, these pop-off valves have one-way operation and are typically placed on the valve cover.
They open at a specified pressure and allow crankcase pressure to vent to the atmosphere.


That's equivalent to on/off throttle to a lighter degree.
The crankcase fluctuates between faster and variable positive and negative pressures.

The article also says a that looser ring package works best with a vacuum pump.
Meaning more mods than just a pump are necessary for optimal performance.

The pop-off valve was introduced in 2010 on plastic oil tanks to help keep them from bursting under pressure.
60Gunner has a full account of the pressure generated and the affects thereof.
Would a pre-04 Sportster engine benefit from a pressure relief valve?
Only if it is already making too much pressure.
And then, that would need to be measured first which none has been so far, as I tell anyway.


This is what I got from the article.
Can you kindly tell me what I was suppose to get from it?
Maybe I missed something?

Hippysmack 31st July 2019 03:44

Quote:

Originally Posted by dieselvette (Post 5766495)
I have a theory about the "purposely leaky" check valves (stock has the "oil drain hole" , krankvent has the "ring" that can be modded) --- this could be simply a liability/safety concern.

While parked, there is the potential for pressure/vacuum buildup in the cc. With the crankcakse totally sealed, and potential for unburnt fuel vapors to exist in the CC (ever drained the oil on a car that wouldn't start, and found it full of gas?). Or, consider if there is fuel above the rings that could be drawn down if the cc is at vacuum.

The intentional "leak" at the check valve(s) allows the cc to stay equal to atmosphere when the engine isn't running. In stock, working form it apparently has little/no effect on the operation while running, and prevents oil from coming out.

Krankvent designers apparently believe the intentional leak has little effect, too, and if connected at the heads while leaving the stock umbrella assy in place, you would also retain the oil catching feature.

Or, maybe it's not a safety issue but a different reason.

As Four Speed mentioned, even without the drain hole, the umbrella will relax and let atmosphere in when parked.

Also, you can't control in which position the valves are in when the engine is shut off.
Most likely, both valves will not be closed as they are at TDC (compression) .
And if they are, you can't control carbon buildup that would let air seep past them.
Any air that gets past the valves on shut down will find way past the rings and equal out the pressure in the bottom end.
Same thing with unburnt gas, it'll seep past the rings also.
So the crankcase should never be totally sealed (although that has been mentioned before as happening due to a stopped up breather valve)
I figure vacuum bottled up in the bottom end would be most noticable just after shutdown before allowed to be equalized if there were a problem.

I'm not sure if it's an intentional leak.
That depends on how much oil actually does get past the umbrella during operation.
Oil is thicker than air and any oil to be drained from that tiny hole would be best done upon a vacuum in the crankcase.
So it might hold more oil than it actually drains until shutdown.

In regard to the larger or smaller amount of air pulled in before the breather closes,
Which one closes faster:
A valve with more air behind it (I'm sure there is a scientific term for that affect) or one with less air behind it, given vacuum in front of either?

edit:
I do believe the drain hole is a potential atmosphere input if there is no oil in there to drain.

This mod is more interesting now.

Middle Rocker Box Spacer (91-03)


This is a mod to curtail the issue of puking oil out the breathers.
86-90 engines do not have a crankcase breather valve incorporated into the rocker boxes.
However, the first answer would address other known factors for wet sumping.

This mod consists of;
Chamfering the umbrella hole to 60 degrees (included angle),
And drilling out the existing drain back hole to 1/8“.

To the extent the drain back hole is enlarged, it bypasses the umbrella valve.
Maybe 1/8” isn't enough to cause an issue,
But the umbrella valve is what keeps the air inhalation/exhalation to a minimum, And inhalation/exhalation is what carries oil out the breathers.
So you don't want to bypass it any more than necessary.

You could probably do the chamfer, but not the drain hole enlargement.
Then, if you still have the issue, you could also drill out the drain hole.

The rocker box middles use the same casting for both the front and rear cylinder.
And there's a facility for the umbrella valve on both ends of each middle spacer.
So you can try this, and if it doesn't work, just move the umbrella valve to the other end and use the rocker box middle on the other cylinder.
In other words, this mod is undo-able, a one time thing.

The umbrella hole is the one in the middle of the picture below.
The drain back hole is the tiny little hole to the right of the sideways 13 in the picture.
http://sportsterpedia.com/lib/exe/fe..._aswracing.jpg

Another suggestion is to enlarge the tiny oil drain from ~.070 to .09375 and add threaded inserts as oil standoffs.


Looking at the pictures below, you can see 3 holes that are in a roughly oval shape area in the corners of the middle rocker box cover. (2 per rocker box, only 1 is used per cylinder)

With each downstroke, the air in the crankcase is forced thru the umbrella valve.
The air has an oil mist in it.
The oil is supposed it settle out in this little chamber and drain back to the cylinder head thru the tiny oil (bottom of oval area).


Slightly enlarging the little hole lets the oil drain back easier.
Air that enters this oval(ish) chamber has to go somewhere.
So it goes out the big hole on top, thru the breather bolts and out.
The threaded insert just provides a lip around the hole.
So any oil that drops out of suspension around the hole won't drain out the breather.


It just makes it a little bit harder for oil to go out the breather.
The inserts below were left overs from another project.
You can use anything that does the same thing.


You can buy a product online called “Slobber Stoppers”. https://www.ebay.com/itm/200917426709
It comes with threaded barrels similar to the threaded inserts below to eliminate oil mist from getting into the air cleaner.

http://sportsterpedia.com/lib/exe/fe...d_3_by_toe.jpg

http://sportsterpedia.com/lib/exe/fe...d_2_by_toe.jpg

In retrospect, isn't the Slobber Stoppers near the same concept as the smaller 04-up breather bolt hole?
The insert sets just under the roof of the box with slots for air to leave and oil is suppose to not climb the insert?
(even though that's inevitable)


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