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

Hippysmack 3rd August 2019 04:59

Quote:

Originally Posted by dieselvette (Post 5767305)
When I say "tuning" I guess is confusing. It's not about pressure or flow from the breathers, but the fact that it's hot air with no oxygen, and possibly oil vapors. That results in a different mixture than with 100% fresh air. At idle this makes up a percentage of the total intake air. But, if the bike is tuned to idle on this shi++y air then OK you don't know the difference until the vents are moved (or oil cap removed).
The more you open the throttle, the less impact this stale air will have on your mixture as it becomes a smaller % of total air. (But, it still has an impact on performance).

Ok.
I understand what you're saying now.
I just haven't pieced it together in my head yet.
I'll play around with it some more tomorrow.
I want to see all I can see before I swap to vent lines.

dieselvette 3rd August 2019 05:19

Quote:

Originally Posted by Hippysmack (Post 5767310)
Ok.
I understand what you're saying now.
I just haven't pieced it together in my head yet.
I'll play around with it some more tomorrow.
I want to see all I can see before I swap to vent lines.

Don't spend too much time on it - the more I think about it, the more I think I'm right haha.

Remember the vent gasses effect on performance has already been proven on Aaron's dyno on no uncertain terms. You're just proving that it affects the burn at idle, too. :)

Hippysmack 3rd August 2019 06:16

:laugh:laugh

Progress in any form is still the same.
It idles better now. Fired it up after blowing it out and dropping the float a little.
Blew out some gas but everything went fine.
I'll tune it tomorrow and go for ride and recheck what where I've been.

bustert 3rd August 2019 07:46

so now you grasp the concept on lazy flow and fuel mix.
finally got a chance to work on the c/c adapter and then father called, seems like someone spiked his computer so another trip out of town. eventually will get it done. i have to use a 6" 5/8-18 bolt to get past my exh and bore a hole through the center, after that, should be smooth sailing.

60Gunner 3rd August 2019 08:22

Not that auto PCVs are frowned on. They don't close fast enough. A car has a lot less crankcase pressure with pistons going up and down at the same time.They aren't designed for a v-twin with both pistons going up and down at nearly the same time.
As a result, they puke too much oil most of the time and don't last very long.
I would use that $200 reed valve I posted a link to.

I don't get a drop of oil with the krankvent in the heads. The failed stock ones are still in place tho. Need a better way to baffle the oil in the cam chest.

dieselvette 3rd August 2019 13:30

Quote:

Originally Posted by bustert (Post 5767327)
so now you grasp the concept on lazy flow and fuel mix.

Ha ha I guess so. I thought you were trying to say it affects actual airflow, but you mean its the crappy air not the flow directly.

When it first occurred to me I was thinking " nah, couldn't be that big of difference" but easy enough to try. But tuning is actually a precarious situation and a little bit of oxygen goes a long way.

But now Hippy is *actually* playing around with the carb so we'll see what becomes of his further testing.

Meanwhile, I've got a long way to go before I can be of any help in these ventures. The indy called yesterday at 530 saying my parts are finally ready, of course I was working the "marathon" shift last night at work because we're leaving for a weeks vacation (bikes not included) this morning, it will be next Saturday evening before I have a chance to dig into the bike project. And that won't be a quick-a-minute assembly there will be lots og fine tuning and double-checking involved with all the changes.

dieselvette 3rd August 2019 13:44

Quote:

Originally Posted by 60Gunner (Post 5767329)
I don't get a drop of oil with the krankvent in the heads. The failed stock ones are still in place tho. Need a better way to baffle the oil in the cam chest.

Thinking back to 2004 when they came out with the new breather design, and all the trouble friends were going through trying to manage oil mess with older buells, I remember being happy to learn of the improvement. That was my motivation for NOT taking it out of the air cleaner (no oil coming out, it shouldn't matter). I wasn't ignorant of the HP difference, I just wanted to keep it simple.

And looking at my intake etc I'm not convinced that venting into AC with the 04 breathers leads to any significant carbon buildup in the combustion chamber. This would be hard to prove with other factors at play, and it takes a lot more miles than most people put on their bikes in its lifetime. But it's a moot point sort of, because it's still more sensible to get it out of there if you're looking for performance or fuel economy.

60Gunner 3rd August 2019 15:16

The loss of performance and carbon buildup has been well documented and makes perfectly good sense if you think about it. I'm sure it doesn't do the carb any good either. It's there because it's nasty enough they don't want you breathing it. Why would you want your motor breathing it?

Hippysmack 3rd August 2019 16:34

Quote:

Originally Posted by bustert (Post 5767327)
so now you grasp the concept on lazy flow and fuel mix.

....Yoda....;)

edit:
Well I'm dead in the water at the moment.
I started out this morning with the only window of decent weather then.
Got to end of the driveway, and started pissin' gas.
Apparently I got the O-ring bowl gasket in a bind and it split on me.
CV Performance is not taking orders right now since they're at the Sturgis rally (what the note on their site says anyway).
Big Swamp said the only HD that had it in stock was in Texas and California.
So I ordered 3 from them.

The rubber was stretched some so I froze it, installed it with a smaller amount hanging over and used a tiny screw driver to nudge it under.
Apparently I nudged it too much inwards.
http://xlforum.net/forums/picture.ph...&pictureid=360

http://xlforum.net/forums/picture.ph...&pictureid=359

I wanted to replace the plastic 90 degree inlet anyway so I'll have time to do that.

60Gunner 3rd August 2019 20:51

See you shoulda bought Twinshot I sold and you'd have a spare bowl for just such an occasion. :p
I was giving it away here actually complete with carb and just about every pilot and main jet you could ever need for $50!
Sold them separate on eBay for $220 total.

Just got back from a good, hard 70 mile run. Not a drop of oil out the breather hose, not a single bubble in the tank, and an oil temp of 197 checked within 30 seconds of shutdown. Gotta pull my seat to get the dipstick out.


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