HPRE

Menu

Members Rides

Easy Rider


in
Members Rides

46 Guests, 3 Users
kodai, phoenixt, Jonno
Welcome, Guest. Please login or register.
Did you miss your activation email?
September 20, 2014, 06:04:00 AM

Login with username, password and session length

 

Author Topic: GoodbyeAirbox  (Read 928 times)

lickeddysplit

  • Neophyte
  • *
  • Posts: 5
  • Karma: 0
GoodbyeAirbox
« on: May 02, 2013, 04:19:37 AM »
I have never liked the look of the air box on my bike. I took it apart and am going to put a cone style filter directly onto the hose going into the throttle body. I am wondering if anybody else has attempted this and what they may have tried regarding the other hose that was in the air box, originating from the crank case? Does anybody know if the smaller exhaust hose from the crank case can be vented separately, or does it require to be tied into the air intake to create a vacuum?

Mcurrier

  • Scooter
  • **
  • Posts: 71
  • Karma: 0
  • 2011 G5
Re: GoodbyeAirbox
« Reply #1 on: May 02, 2013, 04:28:13 AM »
I know on my other bikes, I've always used pod style filters and have always used a smaller air filter (found at any auto parts store) for the crank case breather. You can cut that hose down to about an inch then attach the filter directly to it.

Craig McClure

  • Riding over 50 years
  • Grand Gearhead
  • *****
  • Posts: 793
  • Karma: 0
  • "No Future In Getting Old"
Re: GoodbyeAirbox, Crankcse venting
« Reply #2 on: May 02, 2013, 05:44:32 PM »
I extended my crankcase breather up over the rear fender to the rear of the bike-it vents behind the bike like vintageTriumphs & BSA's did. The short hose with the filter WILL CAUSE AN OILY BUILD UP ON YOUR ENGINE. When it was vented to an airbox it would foul the airfilter over time.
Best Wishes, Craig McClure

lickeddysplit

  • Neophyte
  • *
  • Posts: 5
  • Karma: 0
Re: GoodbyeAirbox
« Reply #3 on: May 02, 2013, 06:02:33 PM »
I appreciate the input. I was hearing anything from it providing warmer air which helps the intake, to it works on a vacuum and won't work properly to it is necessary to vent back to air box for emission control. All from people guessing of course. Will post pics when complete.

barenekd

  • Grand Gearhead
  • *****
  • Posts: 5220
  • Karma: 0
Re: GoodbyeAirbox
« Reply #4 on: May 02, 2013, 06:09:19 PM »
Nope, a hose from the crankcase to the rear of the frame up by the fender works quite well. The other vent hoses can be disposed of, too, along the cannister. One from the tank vent can be routed down to the front frame box. There's one that goes to the injector that needs to be capped off.
I have heard though, that a filter on a short mounting tube will cause problems with the airflow into the injector, resulting in less than desirable running. I don't have any personal experience with that as I kept the original airbox on mine, but just a note for something to be aware of.
Bare
« Last Edit: May 02, 2013, 06:16:21 PM by barenekd »
2013 Moto Guzzi V7 Racer
2011 Black Classic G5 (RIP)
I refuse to tiptoe through life only to arrive safely at death
http://www.controllineplans.com

gremlin

  • Grand Gearhead
  • *****
  • Posts: 1232
  • Karma: 0
  • "Do one thing each day that scares you"
Re: GoodbyeAirbox
« Reply #5 on: May 02, 2013, 06:27:58 PM »
I appreciate the input. I was hearing anything from it providing warmer air which helps the intake, to it works on a vacuum and won't work properly to it is necessary to vent back to air box for emission control. All from people guessing of course. Will post pics when complete.

it's the crankcase vent.  everytime the piston goes up and down the air-pressure inside the crankcase changes.  Add to that a miniscule amount of "blow by" or compression that leaks past the piston seals (rings) - and you have a flammable vapor emission from that hose.

the preferred way to dispose of these crankcase emissions is to feed them back to the engine for combustion.
1996 Trophy 1200
2011 RE B5
1979 XS11 w/vetter terraplane
1981 XS11 streetfighter
1983 Venture Royale
1982 CB750K
1971 Triumph Trident
1969 CB450
1966 Sears (puch) 250


barenekd

  • Grand Gearhead
  • *****
  • Posts: 5220
  • Karma: 0
Re: GoodbyeAirbox
« Reply #6 on: May 02, 2013, 06:51:06 PM »
It's all smog stuff. They have vented crankcases into the air for 100 years. I've never heard of the crankcase vapors staring a fire. Probably has. but I don't recall anytime offhand. Now they vent it back into the engine. I don't think a few Enfields venting it into the air is going to kill the planet. Some of this green crap has gone way overboard. Not that keeping it in cars is a bad idea. It certainly has cleaned up the middle parts of a lane in the road.
Someday soon, cows will have to fart into a tube and have it hooked to their noses to keep all that noxious methane gas down!
Bare
2013 Moto Guzzi V7 Racer
2011 Black Classic G5 (RIP)
I refuse to tiptoe through life only to arrive safely at death
http://www.controllineplans.com

eda1bulletc5

  • Bulleteer
  • ***
  • Posts: 123
  • Karma: 0
Re: GoodbyeAirbox
« Reply #7 on: May 02, 2013, 08:03:41 PM »
Someday soon, cows will have to fart into a tube and have it hooked to their noses to keep all that noxious methane gas down!
Bare

hahahaha...burst out laughing!!...  ;D ;D
2011 RE C5
2012 Honda NC700X 6-speed

lickeddysplit

  • Neophyte
  • *
  • Posts: 5
  • Karma: 0
Re: GoodbyeAirbox
« Reply #8 on: May 03, 2013, 03:32:37 AM »
I remember the same concerns with shortening the hose to the intake, something about the air being too turbulent for proper intake. I am leaving the length of hose as is, I have attached an air filter directly to the stock hose and am fabricating a bracket that will fit the existing drilled holes and keep the new filter from bobbing about.

As for the cow, can you cook beef in a Dutch oven?

gremlin

  • Grand Gearhead
  • *****
  • Posts: 1232
  • Karma: 0
  • "Do one thing each day that scares you"
Re: GoodbyeAirbox
« Reply #9 on: May 03, 2013, 03:39:35 AM »
........I don't think a few Enfields venting it into the air is going to kill the planet. Some of this green crap has gone way overboard.......

I remember driving the Cajon Pass & inland empire in the late 70's & early 80's.  That Brownish/Yellow stuff they used to call air was so bad it would make my eyes burn.

SoCal natives were so tough, we refused to breathe any air you couldn't cut with a spoon.

Tell me you want to go back to those days ?  PCV & CAT may have had some birthing pains, but, the LA basin would be inhabitable by now if it weren't for all that "green crap".
1996 Trophy 1200
2011 RE B5
1979 XS11 w/vetter terraplane
1981 XS11 streetfighter
1983 Venture Royale
1982 CB750K
1971 Triumph Trident
1969 CB450
1966 Sears (puch) 250


Arizoni

  • Grand Gearhead
  • *****
  • Posts: 4350
  • Karma: 0
  • "But it's a dry heat here in Arizona
Re: GoodbyeAirbox
« Reply #10 on: May 03, 2013, 04:06:03 AM »
lickeddysplit
The turbulence you mentioned is one factor and leaving the length alone should help to minimize the effect.

It isn't the only factor that comes into play with eliminating the factory airbox though.

These 500cc engines have a piston that is almost 3 5/16 inches in diameter going thru a stroke that is over 3 1/2 inches long.
That gulps a LOT of air each time it goes thru the inlet stroke.  A lot more than is available in just the rubber hose that used to go from the airbox to the injector body.

Because the cylinder wants more air than the hose contains it must instantly suck the remainder thru the new airfilter.

This is why the size of the old airbox is important.  It serves as a storage place for the extra air to feed the engine so the blockage of the airfilter doesn't become a factor.

If the new air filter has any restriction at all to it (and it will), at high rpm's it may keep the engine from getting a full air/fuel charge.

I say "may" because with the throttle body and the inlet valve in the way there is always restrictions that will keep the cylinder from completely filling but after your modification, don't be surprised if the engine acts like it is running out of power at high engine speeds.

On the other hand, with the setup you are making you will get to hear a LOT more of the intake noise because it will no longer be muffled by the old stock airbox.
For some people that can be enough of a reason to try what your doing.

I guess my main point is, whatever you do, don't just whack off bits and pieces.
Always leave the door open to go back to the original setup if you don't like the engines new top end power.
« Last Edit: May 03, 2013, 04:08:55 AM by Arizoni »
Jim
2011 G5 Deluxe
1999 Miata 10th Anniversary

lickeddysplit

  • Neophyte
  • *
  • Posts: 5
  • Karma: 0
Re: GoodbyeAirbox
« Reply #11 on: May 03, 2013, 02:06:38 PM »
I can't agree more about leaving the door open to go back. I am hoping to finish the modifications this weekend and go for a long test drive. I am expecting a few growing pains as the engine re-learns the air/fuel mix.

I have also lost the peashooter stock exhaust and made my own muffler which I will be tweaking for length and sound. My wife keeps with her all my proper judgement regarding noise level and will be test hearing the variations tomorrow. I wanted more of a straight pipe look, so I removed the chrome shroud and stock silencer, purchased a piece of 1&3/4 inch pipe and two aftermarket baffles. I installed the one baffle(if too loud I can install the second) into the 22 inch pipe, had the local muffler shop stretch the inside of the one end and slipped it on. Its not horribly loud and isn't popping at all, so may be a access.
I will now make two brackets to attach the pipe to the original spots the exhaust system was and wrap the entire thing in an exhaust wrap.

I have kept all removed parts, and am making sure to use all stock screw holes so I can always go back to the way it was if need be.  I just enjoy playing and learning.

ace.cafe

  • Grand Gearhead
  • *****
  • Posts: 8288
  • Karma: 0
  • World leaders in racing or performance Bullets
Re: GoodbyeAirbox
« Reply #12 on: May 03, 2013, 05:05:45 PM »
I don't have a UCE bike in front of me here, because our test mule is up in NJ with Chumma.
However, the engine breather hose should have a one-way valve on it, such as a duckbill, or a fast acting PCV or brake-booster valve, or a KrankVent breather valve.
Even though the UCE has a wet sump and an included transmission housing that gives it more internal crankcase volume, the breather is still important to keep low pressure inside the crankcase.
So, if you trace that engine breather hose system, and see whatever it is attached to, there should be some kind of fast-acting one-way valve somewhere in that route. If there is nothing like that on the breather hose, then you will be pumping air in and out of the crankcase through that hose, which uselessly wastes power, impedes ring sealing, and may even cause some unnecessary oil leaks.
Home of the ACE Fireball 535 Bullet,  Ace GP Hi-Lift Roller Rocker Head . Pistons, cams, etc. Highest performance Bullet engine mods available .  AVL mods. Redditch 700/750 Twin mods. UCE kit soon.

Please visit my new website:
http://groups.yahoo.com/neo/groups/AcePerformanceBullets/info

lickeddysplit

  • Neophyte
  • *
  • Posts: 5
  • Karma: 0
Re: GoodbyeAirbox
« Reply #13 on: May 03, 2013, 06:02:08 PM »
Admittedly I am not a gear head, and a lot of the things I have needed for my modification  have been explained to me by people who use their garage for more than a place to BBQ in the winter. However, I see no valve in the system between the crankcase and where it originally exhausted, which was the air box. It was merely jammed into the air box, unfiltered, and sat approximately 2 inches from the larger air intake hose.

The proximity to the intake was what made a friend of mine believe it may work in conjunction with the intake, either as a vacuum, or to warm the air being sucked into the throttle body.

 If I am missing something, please advise.

ace.cafe

  • Grand Gearhead
  • *****
  • Posts: 8288
  • Karma: 0
  • World leaders in racing or performance Bullets
Re: GoodbyeAirbox
« Reply #14 on: May 03, 2013, 06:23:00 PM »
Well, the intake works to some degree to pull the fumes out.
However, if you are not going to use the intake for that anymore, then it would be advised to put a one-way valve on that hose, so that the valve allows the air to be pushed out, but stops air from being sucked back in.
A duckbill is a cheap and effective valve of this type which is used on the older Bullets for this purpose.
Home of the ACE Fireball 535 Bullet,  Ace GP Hi-Lift Roller Rocker Head . Pistons, cams, etc. Highest performance Bullet engine mods available .  AVL mods. Redditch 700/750 Twin mods. UCE kit soon.

Please visit my new website:
http://groups.yahoo.com/neo/groups/AcePerformanceBullets/info