ADVrider

Go Back   ADVrider > Bikes > Old's Cool > Airheads
User Name
Password
Register Inmates Photos Site Rules Search Today's Posts Mark Forums Read

Reply
 
Thread Tools Search this Thread Display Modes
Old 09-30-2013, 10:25 AM   #1
Sabre170 OP
Gnarly Adventurer
 
Sabre170's Avatar
 
Joined: Nov 2012
Location: Dallas, TX
Oddometer: 246
Oil breather filter mount direction.

Ok, entertain my Franken-brain here for a moment.....

Yes, I know there are a bazillion different oil breather threads out there....couldn't find one addressing this question though. If someone can prove me wrong.....my apologies.

Note: this is not a question of if I should get rid of my airbox and use pods.....already done and too late

So, the most common way to tackle the oil breather with an airbox eliminator is to drill a hole in the airbox eliminator plate and simply connect the breather hose to the filter. This does the obvious and keeps "clean air" from flowing in and out of the breather. Doesn't exactly address the "oil vapor" issue, however, worst case, you get some oil residue in your filter.

My question. Can one do a similar setup, however rather than the filter going straight backwards out the eliminator plate, go straight upwards (I.e. up through the starter cover area). This would continue keep clean air going in and out of the breather. My concern is the oil vapor.....I would think it would go condense and end up pooling at the breather. Assuming the hose has a good seal at the breather, I'm not sure if the oil would pool up there (inside the hose just above the breather valve) and cause an issue, or if the oil would actually re-enter the crank case.

Yes, I know making a "sump tank" or running a drain line back the tail or below the bike are also common solutions to this problem.....I'm not wanting to do this. I'm simply curious as to if ill run into problems with an air filter for my breather were to be plumbed vertically.

(If it matters, I've got a 78 100/7 with assuming the stock breather.)
Sabre170 is offline   Reply With Quote
Old 09-30-2013, 10:54 AM   #2
supershaft
because I can
 
Joined: Sep 2010
Location: San Francisco Bay area
Oddometer: 8,275
It doesn't matter.

I don't run a filter on mine. Reed valves are one way valves. Air doesn't get into your engine there. If it were, your engine's revs would slow, etc.. Plus, my crankcase hose is so long I figure that IF any air is getting back into the engine any dirt in the air is getting stuck on the sides of the hose. I have 130,000 miles experience with said setup. It does not need a filter.

If you rev your engine a lot, a lot of oil vapor will come out of your vent and make a mess. I like keeping my bike clean. Plus it can be dangerous! I have seen SO many photos of obviously just installed crank vent setups that are going to make a mess of the bike as soon as it hauls ass in just one trip but, then again, so many setups never do.

supershaft screwed with this post 09-30-2013 at 11:07 AM
supershaft is offline   Reply With Quote
Old 09-30-2013, 11:31 AM   #3
DiabloADV
Semi-Occasional
 
Joined: Oct 2010
Location: Nor Cal, USA
Oddometer: 2,175
Quote:
Originally Posted by supershaft View Post
I like keeping my bike clean. ...
So...where does the end of your hose discharge the oil mist?
__________________
1974 R90/6 w/1050 kit. Motor only. Seeking a frame.
1970 R60/5

'91 Bill Holland Steel w/Dura Ace[/SIZE]
'01 Z3 3.0 Coupe. The Clownshoe.
DiabloADV is offline   Reply With Quote
Old 09-30-2013, 11:36 AM   #4
Plaka
Brevis illi vita est
 
Joined: Jun 2010
Oddometer: 4,581
Quote:
Originally Posted by Sabre170 View Post
Ok, entertain my Franken-brain here for a moment.....

Yes, I know there are a bazillion different oil breather threads out there....couldn't find one addressing this question though. If someone can prove me wrong.....my apologies.

Note: this is not a question of if I should get rid of my airbox and use pods.....already done and too late

So, the most common way to tackle the oil breather with an airbox eliminator is to drill a hole in the airbox eliminator plate and simply connect the breather hose to the filter. This does the obvious and keeps "clean air" from flowing in and out of the breather. Doesn't exactly address the "oil vapor" issue, however, worst case, you get some oil residue in your filter.

My question. Can one do a similar setup, however rather than the filter going straight backwards out the eliminator plate, go straight upwards (I.e. up through the starter cover area). This would continue keep clean air going in and out of the breather. My concern is the oil vapor.....I would think it would go condense and end up pooling at the breather. Assuming the hose has a good seal at the breather, I'm not sure if the oil would pool up there (inside the hose just above the breather valve) and cause an issue, or if the oil would actually re-enter the crank case.

Yes, I know making a "sump tank" or running a drain line back the tail or below the bike are also common solutions to this problem.....I'm not wanting to do this. I'm simply curious as to if ill run into problems with an air filter for my breather were to be plumbed vertically.

(If it matters, I've got a 78 100/7 with assuming the stock breather.)
Does you breather hose exit the crankcase at the front by the starter?

It only breathes out BTW, not in.
Plaka is offline   Reply With Quote
Old 09-30-2013, 11:57 AM   #5
Sabre170 OP
Gnarly Adventurer
 
Sabre170's Avatar
 
Joined: Nov 2012
Location: Dallas, TX
Oddometer: 246
Quote:
Originally Posted by Plaka View Post
Does you breather hose exit the crankcase at the front by the starter?

It only breathes out BTW, not in.
Gotcha.....only out.

As for where......well, it is hard to explain. I'm working on a cool airbox eliminator mod kinda hard to explain. Basically, I'm McGyver-ing a new airbox eliminator. I've taken an additional front engine cover and a front timing chain cover. Flipped 180....chopped, cut, and drilled. And now where the airbox was, I have a rounded eliminator that is symmetric with the front of the engine. Ya know on the timing chain cover where there are the holes at the top for wiring....well on that part that I flipped 180, I want the filter popping out, vertically from that hole. I'm sure I have everyone scratching their heads asking WTF is this wacko doing!?!

Photos to follow soon.
Sabre170 is offline   Reply With Quote
Old 09-30-2013, 12:02 PM   #6
Plaka
Brevis illi vita est
 
Joined: Jun 2010
Oddometer: 4,581
Does you breather hose exit the crankcase at the front by the starter? In stock configuration. As the bike was made by BMW. Where does the engine end of the breather exit the crankcase. As in, where does the oil get INTO the hose from the engine? At the front of the motor (on top, right) or at the back of the motor(on top, right)?
Plaka is offline   Reply With Quote
Old 09-30-2013, 12:41 PM   #7
Sabre170 OP
Gnarly Adventurer
 
Sabre170's Avatar
 
Joined: Nov 2012
Location: Dallas, TX
Oddometer: 246
Quote:
Originally Posted by Plaka View Post
Does you breather hose exit the crankcase at the front by the starter? In stock configuration. As the bike was made by BMW. Where does the engine end of the breather exit the crankcase. As in, where does the oil get INTO the hose from the engine? At the front of the motor (on top, right) or at the back of the motor(on top, right)?
Oil breather hose connect = front right.
Sabre170 is offline   Reply With Quote
Old 09-30-2013, 12:49 PM   #8
Plaka
Brevis illi vita est
 
Joined: Jun 2010
Oddometer: 4,581
Quote:
Originally Posted by Sabre170 View Post
Oil breather hose connect = front right.
At right rear there is a humpy bumpy cover held on with 3 allen bolts. Remove it.

The disk thing is a reed valve. The thin metal plate moves up to let air out of the crankcase, slams shut so it can't go back. The thick bent up plate keeps it from blowing off. The ragged hole is the entrance to the stilling chamber. That chamber is cast into the right side, top of the block the full length of the starter. The humpy bumpy cover forces the air to come out the reed valve and make a U turn into the stilling chamber. In the chamber the oil mist can separate with cleaner air exiting at the hose connection at the front. Not sure how the chamber is drained. have to look at it again.

If you run your hose up so oil can flow back down it, the oil will just go back into the stilling chamber.

Edit: When you put the HB cover back, use sealant or a new gasket so it doesn't weep. The normal, proper and correct exit of the breather is in the airbox where there is low pressure. breathes better. You are screwing this up, among a huge number of other things.:-)

Plaka screwed with this post 09-30-2013 at 12:58 PM
Plaka is offline   Reply With Quote
Old 09-30-2013, 01:18 PM   #9
supershaft
because I can
 
Joined: Sep 2010
Location: San Francisco Bay area
Oddometer: 8,275
Quote:
Originally Posted by DiabloADV View Post
So...where does the end of your hose discharge the oil mist?
I run my vent through my square airbox. A 3/8ths auto fuel line fits perfectly inside the stock breather tube to the airbox. It has never leaked a drop there but I do put a dab of silicon on the outside of the auto fuel line before I press it up into the stock breather hose. I run that portion of the fuel line to a firewall coupler in place of the airbox's water drain. I drilled the coupler's ID AMAP. Then I attach another hose to the same coupler. It is angled just perfectly to miss the swingarm. Then it angles up and follows the subframe around to the license plate holder where I have an adel clamp that holds the vent hose a few inches past the end of my rear fender. If I don't run those last three or four inches of hose oil will wick back up on my tire and bike at speeds over around 90mph. I ride over 90mph ALL the time. It's funny: Most people don't deal with the crank vent unless they aren't running an airbox. That forces them to deal with the vent. I run an airbox for more midrange (it's really the velocity stacks and not the box but . . . ) and to hold the carbs on but my now highly modified airbbox is really nothing more than a velocity stack holder. I run the vent out to keep all that oil out of my combustion process. I don't keep a real tight top end just to dump oil back in through that vent. That oil causes pinging, power loss, and carbon buildup that leads to even more pinging, power loss, and carbon buildup.

There is usually a drop of milky oil on the floor the next day where I park my bike. The water in that oil gets there in the hose, not in the engine. A lot of the water comes from the combustion process but all that water is a gas and not in liquid form inside the engine. At least until I shut it off.

supershaft screwed with this post 09-30-2013 at 01:49 PM
supershaft is offline   Reply With Quote
Reply

Share

Thread Tools Search this Thread
Search this Thread:

.
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On

Forum Jump


Times are GMT -7.   It's 07:36 PM.


Powered by vBulletin® Version 3.8.5
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Copyright ADVrider 2011-2014