Post by: Rubachabra on July 10, 2024, 01:59:55 PM
Would appreciate any explanation of what these various labelled tubes/parts are intended for. I am just a hobby mechanic so my technical insight is limited, my plan was to get rid of the entire unit and have the air temperature sensor mounted in one of the 4 tubes leading into the throttlebody
I labelled the connections/unit i dont understand with 1-4
English is my 2nd language, so certain technical words and abbreviation might be difficult to understand. Sorry about that. Would appreciate any help on the matter :)
(https://i.ibb.co/V9ZqFMw/image0.jpg) (https://ibb.co/mTwcnhN)
(https://i.ibb.co/4JnNs0Q/image1.jpg) (https://ibb.co/wYF6J2v)
(https://i.ibb.co/B3cmykF/image2.jpg) (https://ibb.co/XLj97HM)
(https://i.ibb.co/MNGGZgV/image3.jpg) (https://ibb.co/kc995G8)
(https://i.ibb.co/yBBf68f/image4.jpg) (https://ibb.co/prr0f30)
Post by: frankenduck on July 10, 2024, 02:07:20 PM
For example, the URL for your first pic is https://i.ibb.co/6s11ryP/image3.jpg
(https://i.ibb.co/6s11ryP/image3.jpg)
Post by: Rubachabra on July 10, 2024, 02:59:39 PM
If you right click on the images at your links and select "Copy image address" then you use the leftmost box above under the "B" above to insert the URL of the image.
For example, the URL for your first pic is https://i.ibb.co/6s11ryP/image3.jpg
Thanks! :)
Post by: Scott_ on July 11, 2024, 06:23:56 AM
It's call a "cyclonic oil separator"
As the engine is running the crank case is intended to be in a "vacuum" state or negative pressure.
#1 is the filter media. usually garbage by now due to age.
#3 is the inlet to the media chamber #1.
#2 is the outlet of filtered air to the throttle bodies to be burned in the engine.
#4 is the oil return line back to the engine block.
Air is drawn from #3 into #1, and out #2 with the separated oil returned thru #4.
I've bypassed mine years ago.
Cap #4 at the engine block, connect #2 to #3 with a PCV(Positive Crankcase Ventilation Valve) valve and be done. Similar to what is done with automobile engines minus the filter.
Post by: Rubachabra on July 11, 2024, 07:25:58 PM
In response to your questions.... the items you have numbered are for Emissions "oil recovery" of the engine vapors.
It's call a "cyclonic oil separator"
As the engine is running the crank case is intended to be in a "vacuum" state or negative pressure.
#1 is the filter media. usually garbage by now due to age.
#3 is the inlet to the media chamber #1.
#2 is the outlet of filtered air to the throttle bodies to be burned in the engine.
#4 is the oil return line back to the engine block.
Air is drawn from #3 into #1, and out #2 with the separated oil returned thru #4.
I've bypassed mine years ago.
Cap #4 at the engine block, connect #2 to #3 with a PCV(Positive Crankcase Ventilation Valve) valve and be done. Similar to what is done with automobile engines minus the filter.
Thank you! This is the first time i've ever heard/learned about blowby/crankcase gas.
Just curious. Since there was an oil recovery system, i assume that there is some oil that follows the blowby gas. Does that trickle of oil just go straight into the air intake after this bypass?
Does the engine need any filtered air intake to avoid a vacume building in the crankcase? I am just watching some videos on the concept of PCV and in it the guy was talking about the crankcase needing ventilation
Can you use any PCV valve, or does the resistance in the valve have to fit the engine? (might be a silly question)
Post by: Reinier on October 04, 2024, 03:31:30 PM
Can you use any PCV value.
What are the specs of the valve on your bike ?
And would it be a good idea to install an oil catch can before the valve ?
Post by: Reinier on October 05, 2024, 02:25:21 PM
No pressure regulation at all.
So why do you need a PCV valve when you remove the separator ??
What am I missing.
Post by: sooprvylyn on October 05, 2024, 03:48:12 PM
I would recommend a small catch can though before whatever filter you attach as enough oil does escape the breather that it will get on stuff over time.
Post by: Reinier on October 05, 2024, 04:10:37 PM
And maybe connect the drain of the catch can with the oil return ?
Basically replacing the cyclonic seperator with a catch can.
Then i should not need a filter And i will have a maintenance free system.
Post by: Laitch on October 05, 2024, 04:19:10 PM
You don't need a valve, you just need something that will prevent unfiltered air somehow getting back into the crankcase.Can you describe your system, soopr?
I would recommend a small catch can though before whatever filter you attach as enough oil does escape the breather that it will get on stuff over time.
Post by: sooprvylyn on October 05, 2024, 05:29:39 PM
I've been putting off dealing w it owing to lack of a good mounting location for the catch can, but i recently discovered sendcutsend to make custom brackets. My plan is to attach an oil catch can to it and again a small filter on the output. In fact this post made me decide to get it dealt with so I've ordered a catch can today and will get a bracket made for it.
There is no need for any valve, but I do think at least putting a filter on it to prevent any potential particles from entering, and especially insects from deciding to make it their home .
This thing is really just emissions control. The only thing that happens when it's disconnected from the intake system is that some oil and small.amount of unburnt fuel may enter the environment. Once i install the catch can ill reduce that a little. The bike will run just fine with literally nothing connected to the breather vent(til something gets into the case from that opening).
Post by: sooprvylyn on October 05, 2024, 05:32:47 PM
Would it de a good idea to connect the crankcase breather hose to a catch can and the the air exit of the catch can to the air return hose of the Cyclonic separator ?
And maybe connect the drain of the catch can with the oil return ?
Basically replacing the cyclonic seperator with a catch can.
Then i should not need a filter And i will have a maintenance free system.
Yes, if you want a totally maintenance free setup and are worried about emissions. You wouldn't need to empty the can very often. In a year I've had less than half an oz of oil come out the vent...probably around 5000 miles or so since I only ride 3-4 days/mo
If you aren't too worried about emptying the can once every year or 2, and you aren't that concerned about the relatively small amount of unburnt fuel escaping the system, then you can just vent it to a filter
Post by: sooprvylyn on October 05, 2024, 06:02:19 PM
Post by: Reinier on October 06, 2024, 04:05:53 AM
Ik dit not think of the pushback from the intake.
Once or twice a year emptying the can I can handle.
I have seen catch cans that come with a small pod filter.
I do like the environment, but if I would be serious about it I would not be riding a bike from 1993.
And in Holland the emissions checks are on cars not on bikes
Post by: Reinier on October 06, 2024, 07:07:34 AM
€24,88 | Universele Auto Olie Opvang Kan Reservoir Tank Met Luchtfilter Slang Schoner Brandstofval Reservoir Auto Voertuig Collector Ketel
https://a.aliexpress.com/_EvVnkNr
It has the baffels and a metal wire ball ( instead of original the BMW sponge ) that does not decay.
With the filter it can be installed pre pcv. And when I do not want to return anything to the engine I guess I'll just blick the outlet port.
When I later decide that does not work I can still a PCV value and connect to the throttle bodies.
I also like that it has a dipstick so no need to open it to check the level.
Post by: Reinier on October 06, 2024, 11:19:44 AM
You are right I do not fully understand the workings of the cyclonic seperator. That is why I am asking questions.
There is little information to be found on the internet and what is there is inconsistent.
There are lot's of pictures of K's with pod filters but hardly any mention of what to do with the tubes connected to the airbox. Your link is a goed example, it tells that the airbox will be replaced by pods but not how.
There are even airbox delete kits available in professional stores but they also have no mention of what to do with the seperator.
Instead of rushing into this I am asking questions. Sees like a good idea.
And I like to hear from people who have already done this instead of just theories.
And as far as I know in the original setup there is no pcv valve on a K1100. So why is it needed when you replace the original device to seperate fumes from oil with another ?
And how would to much pressure buildup occure in an atmospheric ventilated system ? Does the filter create the pressure ?
And if the pressure can not be fully releaved through the filter should the output port then be connected to the throttle bodies?
Post by: Reinier on October 06, 2024, 11:31:44 AM
That guy actually says that Honda has 2 solutions for the breaterhose. One of them being a tank to collect the crap.
If that tank would be sealed it would still have the same compression issue so I am assuming it is vented.
He does not say it in so many words, but that sounds like an oil catch can to me.
And exactly the solution I proposed.
Please explain what the difference is between his and my solution
Post by: sooprvylyn on October 06, 2024, 12:43:45 PM
Thanks for the video.
That guy actually says that Honda has 2 solutions for the breaterhose. One of them being a tank to collect the crap.
If that tank would be sealed it would still have the same compression issue so I am assuming it is vented.
He does not say it in so many words, but that sounds like an oil catch can to me.
And exactly the solution I proposed.
Please explain what the difference is between his and my solution
Yes, catch cans are vented, and they are specifically made for this exact purpose.
Post by: sooprvylyn on October 06, 2024, 01:07:11 PM
There us an inlet where the crankcase gases go from the breather vent. Those gasses pass through a screen/filter which pulls the oil from the vented gas. Then there is either an outlet that you connect to the intake to recycle the gasses(emissions correct), or there is a vent to the atmosphere(won't pass emissions). You run one or the other. Either you remove and plug the cone filter and vent to intake, or you plug the output port and leave the cone filter on to vent to the atmosphere.
Inside the oem airbox was a similar device that pulled the oil out of the vented gases before recycling it.
100% the oil catch can must be vented or you will have the problems laitch mentioned.
Post by: Reinier on October 06, 2024, 02:05:27 PM
And I do know how crankcase breather works.
That is why I don't understand why so often people introduce a PCV valve in the system when the cyclonic seperator is replaced by a catch can. With the information I have my conclusion is they are basically the same.
And did you Notice the information in your videos is conflicting ?
The first video says the a filter direct on you breather is slowly killing your bike. The second says that it is a perfectly good solution.
I never said anything about how I am going to place the pod filters. I got that part figured out. There is plenty of information on that subject.
An additional reason to do this mod is that the original BMW solution can not be maintained. The seperator can not be opened without cutting. And they placed a sponge inside. After 30 years that has decayed and the only place it can go is into the engine.
A good reason to replace it.
My question was very specific for the setup on a 30 years old BMW.
Post by: Reinier on October 06, 2024, 02:20:09 PM
They are placed in a straight line directly behind the radiator.
Which means you are blowing hot air over your air intake.
This is not optimal for performance.
Post by: sooprvylyn on October 06, 2024, 02:24:56 PM
If you delete the airbox, you have a choice of venting breather back to the engine, or to the environment. The oil catch can can be used in either case, tho it's not technically called a catch can when it vents back to the engine. If you vent it back to the engine thro the intake, you will need a pcv valve IF there is any potential for backpressure overcoming the breather and causing pressure buildup in the crankcase.
Do NOT block rhe breather of course.
Apologies to Laitch for my misunderstanding of what he was saying earlier.
Post by: sooprvylyn on October 06, 2024, 02:26:31 PM
By the way in the link of how you think it should be done the location of the pods is open for discussion.
They are placed in a straight line directly behind the radiator.
Which means you are blowing hot air over your air intake.
This is not optimal for performance.
It's not so directly behind the radiator, the pods get pretty fresh air directly above the throttle body. If there is concern you can get angled pods. I haven't had any performance issues with my straight up pods
Post by: Reinier on October 06, 2024, 02:45:44 PM
I was actually looking at a set of angled K&N filters.
I will try the catch can with a filter on top to ventilated.
This will reduce a lot of tubing making a cleaner instal.
Ventilating a bit is ok, my main goal is getting rid of the airbox and the only mess on top off the engine. Which probably means that some of those tubes are leaking. And replacing those special BMW tubes can get expensive.
This will probably be my winter project. At the moment enjoying driving after changing all controls dash and creating a totally new wiring harness.
Post by: Laitch on October 06, 2024, 03:10:44 PM
I never said anything about how I am going to place the pod filters.You are correct. In English, the word if implies uncertainty, or the introduction of a hypothetical situation. Regardless, it appears your introduction to crankcase ventilation is complete. Scott's post explains just about all that's necessary to know about the cyclonic separator, especially considering its likely to be heading to the trash bin during your build.
:laughing4-giggles:
Please post photos of your progress. Good luck with your build!
Post by: Reinier on October 06, 2024, 03:34:56 PM
(https://i.postimg.cc/fJBjydhX/IMG-20230616-142953.jpg) (https://postimg.cc/fJBjydhX)
Current state:
(https://i.postimg.cc/4Y2YpNYY/IMG-20240922-132148.jpg) (https://postimg.cc/4Y2YpNYY)
This winter also planning to fix the fuel gage and do some painting. If there is enough time
Post by: sooprvylyn on October 06, 2024, 04:21:51 PM
That looks nice.
I was actually looking at a set of angled K&N filters.
I will try the catch can with a filter on top to ventilated.
This will reduce a lot of tubing making a cleaner instal.
Ventilating a bit is ok, my main goal is getting rid of the airbox and the only mess on top off the engine. Which probably means that some of those tubes are leaking. And replacing those special BMW tubes can get expensive.
This will probably be my winter project. At the moment enjoying driving after changing all controls dash and creating a totally new wiring harness.
Airbox delete is pretty easy. Just pull everything out, plug the small hole under the radiator, put some caps on the small holes on the back of the throttle bodies, attach a catch can to the breather at the back top side of the engine, fit pods....the last thing you need is a place to put the o2 temp sensor. I have a file for a bracket that will attach to the back of your throttle bodies that puts the sensor right between the cones. Lmk if you want it.
Post by: Reinier on October 12, 2024, 06:18:19 AM
It looks and feels good and came with a mount and a set of different size hose fittings.
But it dit raised a question.
I noticed that the normal filter exit in top is directly connected to the input connector, before the baffels.
(https://i.postimg.cc/CRtDB0YN/IMG-20241012-105645.jpg) (https://postimg.cc/CRtDB0YN)
This confused me.
I expected it to be an alternative output.
When I blok the out and connect the filter there will be no airflow through the can so it will be similar to putting the filter directly to breater hose.
And as sooprvylyn found out that is not good for your filter
I want the catch can to do his work and catch most of the oil in the fumes. And then ventilated the "cleaned" air through the filter.
(https://i.postimg.cc/PLkgXntq/IMG-20241012-105947.jpg) (https://postimg.cc/PLkgXntq)
Does that make sense ? I can easily mount the filter on the out port.
If not where do I go with the output port? To the throttle bodies I assume. And would that be better with or without the filter.
As the crankcase is OEM connected to the throttle bodies with only the seperator in between and no valves I assume this would be an option.
Post by: Laitch on October 12, 2024, 08:09:16 AM
Post by: Reinier on October 12, 2024, 08:37:05 AM
The baffels are the perforated plates in the catch can that are supposed to made the oil in the vapor condensatie.
(https://i.postimg.cc/CRtDB0YN/IMG-20241012-105645.jpg) (https://postimg.cc/CRtDB0YN)
The in-port of the catch can and the "normal" filter port both connect to the same space just above those baffels
Post by: sooprvylyn on October 14, 2024, 12:28:13 PM
1. plug the top hole and put the cone filter on the can output hole...this is the better solution of the 2 and probably what I will do with mine.
2. Plug the input hole, leave the filter on the top as designed, and use the output hole as your input. This is less ideal as the pressure will be pushing up on the filter from the reservoir side, but I think it should still work.
Possible 3rd solution: stuff the wire packing material that came with it into the top of the oil can before you attach the filter on top...instead of in the small packing material receptical between the "screen holes". then plug the output hole and use the input hole and cone as designed. Will probably make it hard to repack at a later date.
Post by: Reinier on October 14, 2024, 12:40:52 PM
Makes the most sense.
Post by: sooprvylyn on October 14, 2024, 01:23:53 PM
Post by: Reinier on October 14, 2024, 02:01:06 PM
But my can came with a mounting bracket that can be bolted to a horizontal surface.
And the airbox is mounted to the top of the engine.
When it is removed they should be some free bolt holes.
I want to reuse one of them. And put the can somewhere in the middle, probably in the lower part of the engine so there is enough room to use the dipstick..
As my engine will be dull black the red can behind the filter pods wil give a nice contrast.
And at the right front behind the radiator I am planning the coolant over flow can made of a Monster Energy can.
(https://i.postimg.cc/QVhXbXg2/monster-super-fuel-watermelon-52411333247307.jpg) (https://postimg.cc/QVhXbXg2)
Post by: sooprvylyn on October 14, 2024, 03:15:14 PM
I mounted my coolant overflow on the right behind the radiator like you plan to do. I used the screw holes in the radiator for the bracket.
Post by: Reinier on October 14, 2024, 03:22:52 PM
And the motronic sits between the frame tubes under the tan/seat.
So I have lots of room left over.
Post by: sooprvylyn on October 14, 2024, 04:22:45 PM
I have a lithium batterij in my seat and also a m-unit.
And the motronic sits between the frame tubes under the tan/seat.
So I have lots of room left over.
lucky....i had to keep a passenger option for the missus, so no under seat battery for me.
Post by: sooprvylyn on October 18, 2024, 11:27:25 PM
I have a lithium batterij in my seat and also a m-unit.
And the motronic sits between the frame tubes under the tan/seat.
So I have lots of room left over.
I found a pretty elegant solution for the catch can. There are 2 potential mounting points, the steel brace in the frame is where I'm mounting, but there is also a threaded ground hole next to the shift lever on the gearbox that is perfectly placed. If I were to mount to the gearbox hole, I'd probably drill it and tap it larger tho. The steel brace is already quite strong, and could be easily modified to fit this bracket on the bottom instead of the top where I have it.
This unit comes with the bracket and fits perfectly. Just need to add a cone filter and swap the input hose barb to a 1/4 npt x 5/8" barb fitting(or a G1/4 to 14-16mm hose barb if you can find it).
Comes in red too
Catch Can New HEMI Technology Z-Bracket fit for Scat Pack & Shaker 11-21 (Red) https://a.co/d/eZsKzBq
Post by: Reinier on October 19, 2024, 10:41:03 AM
I can not do that as all that space between the frame is already used.
An I am trying to get the see through of the triangle in the frame as clean as possible.
By the way I can still carry a passenger if needed, but not planning to. I restored the misses bike last winter so she can not complain.
(https://i.postimg.cc/Z9xP6skS/IMG-20240609-115227.jpg) (https://postimg.cc/Z9xP6skS)
I hope the paint job on mine will be just as good
Post by: sooprvylyn on October 19, 2024, 11:27:13 AM
Anyway, just wanted to alert you to an option that seems to be well purposed and well fit to our specific bike.
Post by: Reinier on November 19, 2024, 02:58:22 PM
I removed the throttle bodies and gave it all a good clean and installed the new filters. I also removed the 4-way hose and capped the tubes on the throttle bodies.
(https://i.postimg.cc/RNzSMnpz/IMG-20241119-200503.jpg) (https://postimg.cc/RNzSMnpz)
(https://i.postimg.cc/Mf1z7WT4/IMG-20241119-200524.jpg) (https://postimg.cc/Mf1z7WT4)
I found some oil residu on the butterfly values what makes sense when the breather fumes are returned there.The new setup should keep them cleaner.
Now I need some pliers to refasten the clips. Then some more cleaning and some inspection of the header rubber before they go back on the bike.
I did do a preliminary test of the filters in combination with the catch can and all was fine. Maybe even a bit better then before.
Post by: sooprvylyn on November 19, 2024, 09:20:57 PM
https://a.co/d/gQfyWnG
If your intake boots are cracked as they often are, you can look for some 40mm boots like these instead of ordering the oem ones. I bet you can find the same thing in black too. These are super beefy and durable. I have zero worry about them ever cracking.
Post by: Kaos on November 27, 2024, 03:01:15 AM
Post by: Reinier on November 27, 2024, 04:32:41 AM
The breather is no longer connected to the TB. But to the catch can. Oil fumes are caught there and not fed back into the TB
Post by: sooprvylyn on December 24, 2024, 09:35:38 PM
Soopr, i think he ment the intake manifolds, as he has connected the breather directly to the TB. Some here refer to them as boots.
Yeah, I used them instead of the stock boots to connect the throttle bodies to the intake manifold.
Post by: Mill on March 05, 2025, 10:40:33 AM
I saw they were blocked off and wondering is that okay long term or main purpose, they are $160 for OEM from euromoto and don't know if that was needed or not.
Looking at following this for air box delete.
The second thing was the front breather hose near the radiator, does this need be blocked off or routed with the catch can on this.
Post by: Reinier on March 05, 2025, 11:19:14 AM
When you remove the airbox you also reduce the spitter. No splitter nothing to return. And nothing to return means you can cap the engine connection at the front.
The only air actually builds up as a black residue in your throttle bodies. Your air intake will be cleaner an steadier when you block those 4.
Now you only need something to Not dump the oil on the street. you can do that with a catch can.
Of course this is for an older K1100 that has no airmass sensor.
It does have an airtemp sensor in the airbox but no airmass sensor. The airtemp sensor you need to relocate to the throttle body.
In my post a little bit up you find pictures of my throttle bodies and you can see the hose connections capped and the bach of the airtemp sensor
Hope this helps
Post by: Mill on March 05, 2025, 01:09:15 PM
It transport an air oil mixture that comes from the carter due to over pressure, Do you mean air / fuel mixture?
And does this not effect the fuel/air mixture, you go on to later talk about a the The only air actually builds up as a black residue in your throttle bodies, does this mean that you have to clean your carbs more often or is there a solution to fixing this black ressidue?
If possible would it be better to take the 4-way hose and add it into the catch can at some point? (see below) Or what is officially come out of it the 4-way hose, is the thing I am not understanding.
I am assuming you would need a pcv or some sort of double check valve in before the catch can to make sure there is no back pressure.
IMG_3453.jpg (60.48 kB . 768x576 - viewed 547 times)
Post by: Reinier on March 05, 2025, 01:41:28 PM
In you drawing there is the crankcase breather. When the engine runs and the cilinders move there are moments of high air pressure the crankcase breather is to get rid of this pressure.
Because the engine is lubricated with oil and is hot a mix of air and oil vapour comes out of the crankcase breather.
In the original setup this mix goes through the splitter that sits in the airbox. This reduces the amount of oil in the mix. The remaining air and oil vapour mix goes through the 4-way hose in your throttle bodies. A K1100 does not have carbs. In time this mix builds up in your throttle bodies as black residue.
After you remove the 4-way hose and block the connections to the throttle bodies only air that comes from your new air filters will pass through the throttle bodies and no more oil. So the stay clean.
Your drawing is good except 1 thing. Remove the 4-way hose.
Post by: Mill on March 05, 2025, 01:59:22 PM
The 4-way is the connector for entry, not exit.
The reason I thought they were there were some sort of BMW engineering to sync airflow evenly though the carbs to alleviate pressure differences or something, but that is not the case at all rather its just oily/dirty air going to carbs to be re-burned. I will be blocking these off.
On a side note, did you get your 40mm intake manifolds from kpartsholland? or a different site? $226/€209 is quite expensive for the rubber and intakes
Dankje
Post by: Reinier on March 05, 2025, 02:30:45 PM
I got this set https://www.caferacerwebshop.com/nl/powerbrick-luchtfilterset-bmw-k-serie.html
The tubes are 3d printed and fit perfectly. The filters are included and high quality.
I was concerned about getting filters with sufficient airflow. And the powerbrick website and the filter brand convinced me. But they are even more expensive.
And the fit in the black and red theme of the bike.
Post by: Mill on March 05, 2025, 03:31:28 PM
And no, but my work sent me abroad to Nijmegen for a while.
Post by: sooprvylyn on March 05, 2025, 06:39:46 PM
I understand!
The 4-way is the connector for entry, not exit.
The reason I thought they were there were some sort of BMW engineering to sync airflow evenly though the carbs to alleviate pressure differences or something, but that is not the case at all rather its just oily/dirty air going to carbs to be re-burned. I will be blocking these off.
On a side note, did you get your 40mm intake manifolds from kpartsholland? or a different site? $226/€209 is quite expensive for the rubber and intakes
Dankje
It is correct, on a 4v k bike there is a lot of enviromental control in the air intake system. You can remove the "4-way breather" and just put plastic caps on the small holes on the back of your throttle bodies. Attach a catch can to the breather vent at teh back of the engine. Attach pod filters or a plenum to the throttle bodies, and make a place for the o2 temp sensor to measure the intake air temp. I have a bracket file if you need it for the air temp sensor. Look in the 3d parts forum.
For the intake boots, you can actually get some 40mm silicone boots on ebay that fit perfectly. They come in red, blue and black. Here is the link: https://www.amazon.com/dp/B07QQQ83QL?ref_=ppx_hzsearch_conn_dt_b_fed_asin_title_9&th=1
The boot that is nearest to your throttle advance lever(choke) will seem like it wont fit, just tighten the clamp and you will see it does fit.
You can see the red silicone boots from teh link above, and also you can see the o2 temp sensor bracket I mentioned, in this photo. This photo was taken before i removed the 4-way breather on back. Now it is gone and only has small red plastic caps on teh holes.
LAst, there is a small hole above your timing chain cover just below the radiator. Plug it with a silicone plug(heat resistant). This hole is also part of the emissions system. It allows the crank case breather oil to go back ito the engine. Once you delete the airbox, it serves no function. If you dont block it, the timing chain will spit some oil up from that hole and it will get on your engine
Post by: sooprvylyn on March 05, 2025, 06:44:29 PM
Post by: sooprvylyn on March 05, 2025, 06:49:43 PM
https://www.youtube.com/watch?v=nxOKNst8BCY
Post by: sooprvylyn on March 05, 2025, 07:07:52 PM
Post by: Mill on March 06, 2025, 09:07:48 AM
And where is your it vent for your catch can?
And If any OEM farings are re-installed, would you see any decrease in airflow to the pods, I plan on having fairing(s) still be somewhat installable for winter months of driving
Thank you a ton for the extra photos and video, helped ALOT!
Post by: sooprvylyn on March 06, 2025, 02:49:01 PM
Yes, if you put the big fairings back on the bike, you will restrict airflow, and you will also be sucking hot air from the radiator instead of cooler outside air. The OEM setup sucks air from in front of the bike for this reason. If you are planning to use fairings, I would recommend using a plenum and routing the filter/intake nozzle outside of where the fairings will sit.
The vent for my catch can is a small pod filter on the catch can. Watch te video again and look carefully at the catch can, you should be able to see a small blue pod up there with silver caps(upper right side of the video frame). If you want details about this specific catch can let me know. I can link you the parts I used and how I connected it all. 99% of catch cans you'll find on amazon or ebay are massive and have a flawed design. The one I used took some trial and error to locate, but it comes with a mounting bracket and there are 2 pretty good places you could mount it on the bike, depending on what you are doing with your frame. This catch can unscrews the cup from the cap for emptying, and the bracket is on the cap(ie you need no tools to empty it).
Post by: jbt on March 15, 2025, 04:42:35 AM
What do you want to do? Take a photo of your K or ride it?
There are lot's of pictures of K's with pod filters but hardly any mention of what to do with the tubes connected to the airbox.
If you want to ride it, don't touch to the airbox.
An atmospheric engine, overall a fuel injected 4 inline motorcycle engine is designed to work with an airbox. The FI system needs to work properly that the intake is enclosed in a quiet environment, without turbulence. That's the first purpose of the airbox. It permits to control the pressure and the amount of air available. Don't worry, the dimension of the airbox and the air filter is far enough: it could feed 4 K engines at full throttle. By the way, you'd be surprised how performance, measured on a power bench, could be changed by a single subtle change of the intake airbox diameter...never to be enhanced, always to be degraded. BMW engineers of the eighties were not idiots. ( Today... :think )
Another purpose of the airbox is to measure the air temperature accurately: this is crucial for the ECU as, without air flow meter like there is on K2V, the amount of air sucked is estimated by its temperature in the airbox and the RpM value. You know that pressure and temperature are linked... By removing and relocating the air temperature sensor elsewhere without calibrating it or re-mapping the ECU, the value it sends will be inaccurate.
Crankase case pressure management is also important: if you reduce the ventilation flow of the crankcase, it will reduce power of the engine, but also will create stress on the gaskets and provoke oil leaks. If you replace it by an shiny chinese cheap air pod that will clog within a few kilometers, you will also have to face very regular maintenance issues.
Recycling oil vapors is another function of the airbox. Yes, I know, you don't care about environment policies. You probably have another source to breathe air, or gills? But your engine needs this oil also. It lubricates, modestly but usefully, the admission valve stems and the guides. Why do you thing there are valve gaskets?
Last but not least, you will notice that when opening the airbox, each port has a velocity stack dedicated. With a very specific lenght and shape so it's accorded to erase flat spots of the power curve at some rpm . Remove it and replace it by standard crap pods and it will ruin the admission harmonics. And, at it is usually measure, will reduce the amount of air that could be admitted in the engine: anyway they will never improve it as it only depends of how the engine sucks.
If it's only to shine on social media, do anything anyhow.
Post by: Kaos on March 15, 2025, 11:34:23 AM
If you want to ride it, don't touch to the airbox
If you replace it by an shiny chinese cheap air pod that will clog within a few kilometers, you will also have to face very regular maintenance issues.
Not entirely true. I've done multiple tours (about 12k in kilometers since deletion) with a deleted airbox and MAF sensor on a 2 valve (using a temp sensor and a v2.1 ecu). And it runs and rides like sunshine. However, I am still in the phase of regular checks minor ajustments since I've came up with the solution of the airbox/maf sensor delete on a 2v.
Just do keep in mind some things might be different. It takes some fiddling with the intakes to get it smoothly [as in ajusting the throttle body].
You will probably have a higher fuel consumption. Well at least I do have more fuel consumption, but that was what I expected and was warned for.
What you'll notice on a cold bike with Low RPM that it tends to feel more clunky.
when it comes to an airfilter on the crankcasebreather, which I currently use (for a BMW M3) works fine, but its messy as hell. Dont recommend using an Airfilter.
I dont know about the clogging, since mine hasnt, but it sure as hell makes me have to clean the empty open oven. Also people dont like riding behind me. So 10/10 I would recommend a catchcan.
The Air Temp Sensor ideally should go inside the intake if possible. Many people will put it into the elbow/boot of one of the pods if there is room to do so, or into any plenum they use. I dont think there is a marked difference between the air entering the pod and the air that is 1 inch away from the air entering the pod.
Frankly there is having it out in the open will cause a detection of colder air due to airflow on a higher speed, than the actual air inside the elbow or airfilter. Would recommend sticking it inside the pod or elbow as close to the front as you can.
There appears to be little economy options out there.Economy option: https://cafe4racer.eu/en/air-filter-adpaters-bmw-k-100-k75-k1100/23096-bmw-k1-k100-16v-k1100-set-of-4-air-filter-with-rubber-adapters.html?srsltid=AfmBOoqYe_aITbvwjbnArD1crIpD-XeYEJp_stHV5VQc-CPXq0V7p-7K
these fit perfectly and arent rebranded fancy smancy airfilters and you could always get some others later on. These are rubber elbows btw, not printed.
Otherwise check this dude's shop: https://customcaferacerparts.com/nl/collections/all he spend quite a bit of effort to craft and design his sets.
When it comes to hoses. All fuel hoses go back where they belong.
Airbox delete == airbox delete, this includes the hose to the crankcase and (can you call them that?) hoses from the plenum chamber to the throttle body.
If you are going to use a car CrankCase breather filter like me, it will come with a - i do believe 21mm hose + clamp, but dont pin me down on the size - and some catch cans do as well.
Other than that it's pretty straight forward
Post by: Kaos on March 15, 2025, 11:53:19 AM
here is a video I made of my setup on my 4v bike. Sorry for some of the stuttering, old phone.
https://www.youtube.com/watch?v=nxOKNst8BCY
Fair is fair, looks good. But it also looks like you've overcomplicated it for yourself. Not as complicated like the dude i've met running Carburators on a k100. But still
Post by: Reinier on March 15, 2025, 03:42:04 PM
And as this a old police bike it is highly over engineerd. Maximum top speed is not a goal, or even allowed on the road. And as I have remover 50kg from a 300kg bike acceleration is great. So a little dip in performance ( if it would happen) is not a real problem.
I also think it depends on the quality of the filters.
And the BMW engineers where no Fools but they did have to work with the available materials and knowledge. An they where only human.
It breather is as critical as you say they should have made the cyclinic seperator maintanable and not fill it with materials that decrade over time and then seal it. After 30 years it does not work anymore and part of the filter can get in your engine. Also everybody has at sometime a leaking breather hose and that does not instantly result in the issues you described.
And a little extra maintenance ? After 250.000km it requires and deserves some extra maintenance anyway.
Post by: Kaos on March 15, 2025, 04:09:29 PM
or even allowed on the road.
And esp the respective BMW hobbyist would never ever disobey any traffic laws :laughing1:
In all fairness, stripped down without windshields none of us will hit the maximum speed without internal bleeding from the turbulence and lose all sense of comfort at 130 kmph plus
Post by: sooprvylyn on March 17, 2025, 01:48:41 PM
Fair is fair, looks good. But it also looks like you've overcomplicated it for yourself. Not as complicated like the dude i've met running Carburators on a k100. But still
What's complicated about my intake? It's about as uncomplicated as it can be.
Post by: Kaos on March 20, 2025, 05:46:06 AM
What's complicated about my intake? It's about as uncomplicated as it can be.
I am Used to the 2v throttlebody setup, and my 4v TB on a 2v, and because of that I thought you've risen your throttlebody taking extra steps with all placements of the components, thus over complicating.
But I was wrong, I didnt think of the fact that I was looking at an actual 4v and not some hybrid frankensteined version.
Post by: Laitch on March 20, 2025, 12:23:08 PM
Fair is fair, looks good. But it also looks like you've overcomplicated it for yourself. Not as complicated like the dude i've met running Carburators on a k100. But stillBut still, that Brick with the tri-carb setup looks pretty good—carburetors not withstanding. Here are some photos from 2024
(https://www.motobrick.com/gallery/4/1601-200325121733.jpeg)
(https://www.motobrick.com/gallery/4/1601-200325122039.jpeg)
Post by: Kaos on March 20, 2025, 12:44:45 PM
Post by: Laitch on March 20, 2025, 02:10:25 PM
I do fancy the looks of it. All i've understood from the brick enthousiast i've encountered with his carbed k100 is that its quite a configuration hassle to get it running smoothlyIf the carbs have clean passages and undamaged jets, all it should take is clean, high octane fuel, the experienced use of an accurate manometer, acute hearing, and good spark plugs. The use of E10 shouldn't be a problem. It certainly takes more effort than having an effective electronic engine management system, but think of the multitude of copulation opportunities it's sure to attract. The Brick's fuel injection system just isn't as shiny. :laughing4-giggles:
Post by: Kaos on March 20, 2025, 04:31:43 PM
If, and only if there appears another wild brick on my path this shall be the route ill take. From a wiring point of view this would be a pretty clean build.
Post by: Laitch on March 20, 2025, 06:05:51 PM
Sold.Maybe you'll find one of these 35 year-old Luftmeister systems discarded along your route. 112350
If, and only if there appears another wild brick on my path this shall be the route ill take.
(https://www.motobrick.com/gallery/4/1601-200325180146.jpeg)
Post by: sooprvylyn on March 20, 2025, 11:39:59 PM
Sold.
Was it the multitude of copulation opportunities that sealed the deal?
Post by: Kaos on March 21, 2025, 03:28:14 AM
Was it the multitude of copulation opportunities that sealed the deal?
I would be lying if I said it wasnt.
Maybe you'll find one of these 35 year-old Luftmeister systems discarded along your route. 112350
(https://www.motobrick.com/gallery/4/1601-200325180146.jpeg)
These are somewhat of a holy grail. I would most definitely pick these up if they came on my path (unless they'd cost me a second mortgage)
also: :threadjacked
airbox discussions are dangerous.
Post by: Reinier on April 27, 2025, 03:36:13 PM
The airbox is removed, the frame powder coated and the rest painted.
Here is a video of it's first startup after the build.
First run (https://www.motobrick.com/gallery/videos/8237_27_04_25_4_41_38.mp4)
Post by: Laitch on April 27, 2025, 04:54:22 PM
I had some other projects like a child's wedding.Isn't the minimum age for marriage Holland still 18 years? I've got to admit, it probably makes wedding gift-giving less expensive if it isn't—xboxes, skateboards, stuffed animals, dolls, gift certificates for Happy Meals at McDonald's, robotic puppies, Legos, etc.
Post by: Kaos on April 28, 2025, 01:07:45 AM
Isn't the minimum age for marriage Holland still 18 years?Same as the USA. 16 to 18 with the parents consent, 18 is legal. However then you're allowed to drink at your own wedding. Still a child though and the groom would probably still be happy with an xbox. Bride.. less often.
Anyway. Good going Reinier. Hidden battery - a anti gravity batt under the tank? -
Did you do something with the can? As in sprayed it with some 2k?
Some unwanted advice. Go for a rear fender/mudguard otherwise you're going to have a bad time keeping it clean.
Post by: Laitch on April 28, 2025, 10:11:58 AM
Here is a video of it's first startup after the build.Do you know what is causing the low-pitched, rhythmic knock I hear as the mic is passing over the tank between 0:05 and 0:10? Does it stop when the engine revs increase.
First run (https://www.motobrick.com/gallery/videos/8237_27_04_25_4_41_38.mp4)
Post by: Kaos on April 28, 2025, 10:13:35 AM
Post by: Laitch on April 28, 2025, 10:37:43 AM
Power dwarfs with a hammer. I suggest you remove themOnly one hammer? They're sharing resources and saving the planet, bless their little hearts!
Post by: Kaos on April 28, 2025, 11:11:11 AM
Only one hammer? They're sharing resources and saving the planet, bless their little hearts!
Bless the dwarfs!
Anywho. My best guess based on really not much to go with is the camshaft pushing the valve tops of the exhaust valves since theyre synced with the exhaust puffing. Why and how, i dont know. Maybe a lack of lubrication on that side.
Id advice would be to find the sound origin yourself and film that, maybe even with some throttle usage to see if it speeds up.
Post by: Kaos on April 28, 2025, 11:17:55 AM
Post by: Reinier on April 28, 2025, 12:00:19 PM
If you mean the gastank with " the can" then yes Candy Apple red with a 2k clear coat.
I still don't know what to do with the fenders. But i'll figure it out.
The battery is an Ultrabatt in the saddle
Post by: Kaos on May 25, 2025, 12:20:54 PM
But. What I was Wondering, did you find the origin of the rythmic knock? And was it the camshaft?
Post by: Reinier on May 25, 2025, 12:58:29 PM
The sound is still there. The valves are all within specs. Compression is similar on all cylinders.
The only thing I can find is lower intake vacuüm on cylinder 3 but I can not find a leak.
So synchronisatie is not complete and everyone says that might be the issue.
Post by: Kaos on May 25, 2025, 02:40:53 PM
Of sync, as in timing not being correct?
The leak might be in the boot, the intake manifold mounted to the engine.
Post by: Reinier on May 25, 2025, 03:39:55 PM
Post by: Kaos on May 25, 2025, 03:46:02 PM
Another option is to remove the camshaft cover,
Have the bike in neutral and manually turn the engine using the hexnut in the timing housing to find the origin
Post by: Reinier on May 25, 2025, 04:29:14 PM
Timing I did not check that. Should be ok. The only timing related thing I have loose is the hall-sensor because you need to remove that to remove the timing cover for painting. The chain and tension er look in good condition. I will look into that further coming week.