K1100 airbox removal and fitting open air filters

[saints]

Before pointing fingers at me for bringing this up again, bear with me.. I can explain.. maybe..

I have searched a lot about this subject, but every thread on every site kind of stops before revealing the final solution for the completed modification, or there are some details that are not clear for beginner like me. So maybe this time we can get it once and for all in the same thread for all future children´s to read. With clear(?) pictures. With proper tags and search words so it can be found easily.
Bike is K589 K1100RS (EUR, not USA), 1996, Type Code: 0522 and it has roughly 130 000 km behind.
I have taken apart the airbox and hoses connecting to it, it seems that almost all vent and vacuum hoses are cracked, so I will have to replace them all in the process. Also two out of four rubber tubes that connect airbox to TB are cracked.
I see 3 options, either way I will have to purchase (11 15 1 461 835 VENT HOSE and 11 15 1 461 834 HOSE:

1)   Keep airbox, find used airbox-tb tubes or replace all with new OEM (very expensive)

2)   Keep air box, Try to DIY repair those airbox-tb tubes somehow (high risk needing to replace in near future anyway..)

3)   Remove entire airbox, install open air filters (for example the kit that powerbrick sells (https://powerbrick-parts.com/collections/k-series/products/open-air-filter-kit or I can 3D print something similar and just buy the filters, so quite low-cost), connect TB 4to1 hose on top of timing case, make 4to1 for cranckcase vent and install PVC in between

Picture tells more than few words, so I have taken some and sketched some drawings about the third option.
Have I understood this airbox-to-open air filters-modification correctly? Nothing has been done yet.. will wait for the professionals opinions. Are there any downsides to this, other than warmer air to intake.. crankcase blowout goes straight to TB, slightly more emissions and sound for the world? Has anyone real-world experiences with this kind of modification?

Thank you for your patience to read this mumble to the end.

[Chaos]

ohhh, I like the look of the quad filters!  No idea how it would work on your K but I converted my K75S decades ago with no ill effects

[Laitch]

Welcome to the show, saint!
In the photo of Option 3 Part 2: Are you proposing to use the large hose (marked for connection to a crankcase port by the green line) to direct crankcase blow-by vapor into the throttle bodies?

[saints]

If I understand your question, yes, that is the plan. I was going to leave the cyclonic oil separator out of the mix, or maybe I could get aftermarket separator, if that is recommended? If I do not have oil separator is there risk of getting oil-gunk in the tube and possibly get that blocked, or messing the throttlebodies with "dirty" air? Supposedly the cyclonic separator normally takes care of those impurities before letting air to the throttlebody.

Or is it just being enviromental friendly, to use oil separator?

Attachment a picture from the march order of the cyclonic separator and hoses connecting to it, am I getting it right? I can´t get the darn thing apart, maybe that is not supposed to be done, there is nothing to service there? I read there is a sponge inside, but the exact structure remains a mystery.

[saints]

ohhh, I like the look of the quad filters!  No idea how it would work on your K but I converted my K75S decades ago with no ill effects

And to Chaos, hopefully I will achieve as working solution as you did!

[Laitch]

Is it your opinion the 4 into 1 collector connected to a tube protruding from the rear of each throttle body is part of a vacuum assembly?

[saints]

Is it your opinion the 4 into 1 collector connected to a tube protruding from the rear of each throttle body is part of a vacuum assembly?

To be honest, I have no idea. I thought that since that hose (11 15 1 461 834) is connected to the back of the throttlebodies, there must be vacuum in that hose, rather than overpressure, since there is intake/vacuum in throttlebodies that it is connected to?

Blowout from crankcase --> to the oil separator --> oil drops to bottom, air goes back to the throttlebodies via that hose? To me it sounds logical..

Or is this wrong assumption?

[Laitch]

To be honest, I have no idea. . . . Blowout from crankcase --> to the oil separator --> oil drops to bottom, air goes back to the throttlebodies via that hose? To me it sounds logical..

I'm just trying to understand your thinking, saint. I'm not one to operate on assumptions.
Have you read this thread? Here's what it can look like in that separator.

There is also some published experience that the length of the intake tubes from filter to throttle body improve the torque range, so maybe that is a consideration, too. This thread is interesting.

.

[saints]

I'm just trying to understand your thinking, saint. I'm not one to operate on assumptions.
Have you read this thread? Here's what it can look like in that separator.

There is also some published experience that the length of the intake tubes from filter to throttle body improve the torque range, so maybe that is a consideration, too. This thread is interesting.

.

I agree with you Laitch, assumptions often lead to errors. Good links those, good that someone had cut it open for the rest of us.

That thread led me to this solution (option 4) that acftfliehr had done in 2007 (http://k11og.org/forum/viewtopic.php?p=24604#24604). Excluding the use of airbox of course..

Could this modification taken forward by adding oil separator (option 5) or even also connecting the separator to the drain (option 6). Option 6 would be quite close to the original?

Is Oil separator and/or PVC valve an overkill?

This https://www.k100-forum.com/t8933p50-big-block-k100#112357 intake solution looks and seems good.

[Laitch]

The oil separator was a pollution control refinement to satisfy the continuing development of emission control legislation. If the moto isn't being ridden in a ULEZ district under strict enforcement but rather being ridden in a Who Cares,We Don't district then the separator isn't necessarily essential unless there's high oil content in a significant amount of blow-by vapor. Maybe the exhaust will smoke a little; maybe the throttle bodies chambers might start fouling but neither is happening in my homely K75 with its antediluvian z-tube breather missing a cyclonic gizmo, so another option is not to get twisted about whether you use one.

[lewisnort]

I’m someone with a new(to me but severely battered) brick that’s also my first time working on anything pretty much so as you can imagine lots of research involved for me switching to pods.
It seems from this I could rig up the accumulator to keep it as close to stock as possible but what would prevent me from just sticking a filter on the crankcase breather and plugging up the oil return?
Other than a potentially very oily filter that I don’t mind dealing with?

[Laitch]

. . . what would prevent me from just sticking a filter on the crankcase breather and plugging up the oil return?

If you have free will, nothing would prevent you. 

[The Mighty Gryphon]

The easiest way to see why you shouldn't do something is to just do it.  Experience is the best teacher. 

Painful at times, but the lessons are always well remembered.

[lewisnort]

Looks like I’ll have to just commit to it then  powerbrick do sell a tiny pod filter specifically for capping off the breather hose and it’s under 30 quid. In 3 months or so when I finally get round to starting, getting all the gremlins out stripping it and putting it back together, I’ll have a go and report back.

[Laitch]

Looks like I’ll have to just commit to it then 

You still have free will, and risk carries its own reward. The entire conversion to pods is fraught with performance disappointment if undertaken with limited knowledge of how the engine system works and instead is based on solely appearance. The Big Block link in Post #8 explains one customizer's experience with the conversion.

[lewisnort]

Hmmm, so potential torque losses down low then if my untrained eye can comprehend it, I can live with that this bike is just meant for me to learn on for now.
In saints many options post is option 6 essentially removing the separator from the airbox but keeping it plumbed up all the same?
Aside from relocating the crankcase outlet to now attach to the end vacuum instead of in the middle.
If I’m not mistaken the oil separator doesn’t interact with the inside of the airbox at all so the entire system wouldn’t notice it missing. Am I wrong here?
This seems like the most ‘i don’t wanna deal with that’ way for me.

[saints]

Update to this topic. I found very cheap replacement for the airbox.. 20€ plus postages, so I renewed the old one and kept the original setup.

But.

I did get the oil separator apart without breaking it.. had to cut the airbox a little bit. Inside it had mushy foam, stacked as one with oil gunk.. don´t think much fumes has got past that in a while. So scraped that gunk out and put it back together. Probably wont separate so much oil as with intact foams inside, but at least fumes get through.