07 Rerouting Breather Hose


14 replies to this topic
  • Twig323

Posted February 27, 2007 - 11:15 PM

#1

I was rerouting the breather house on my 07450f and was wondering where you guys placed it and if you had to cut it or not. I just cant find a suitable place for it.

  • grayracer513

Posted February 27, 2007 - 11:23 PM

#2

Leave it where it is. Put a T in it at the top and run a second hose into the air box.

  • DaveJ

Posted February 27, 2007 - 11:40 PM

#3

Leave it where it is. Put a T in it at the top and run a second hose into the air box.


For concerns of deep water crossings or am I missing something?

  • swatdoc

Posted February 28, 2007 - 01:18 AM

#4

I spoke with the supermoto team manager at Mach 1 motorsports a week or so ago, and he told me they would be coming out with an oil breather containment/recapture setup in a couple months. Not only will it recapture oil that would have been lost through the breather, but it somehow lowers crankcase pressure and they have gained 1 1/2 horsepower with the setup

  • WB450

Posted February 28, 2007 - 08:38 AM

#5

Leave it where it is. Put a T in it at the top and run a second hose into the air box.



Is this to lower crank case pressure?

  • grayracer513

Posted February 28, 2007 - 09:06 AM

#6

For concerns of deep water crossings or am I missing something?


Is this to lower crank case pressure?

Most concerns about the breather relate to worry about water crossings, or the belief that the breather will pull dirt or sand up into the engine. Putting two separate hoses on it, even if the second one is much smaller, prevents the engine from ever developing enough vacuum to raise water up the the main lower leg of it. A running engine would normally not do that, anyway, but if the engine stalls in deep water, the last couple of upstrokes as it stopped could. Also, if an attempt is made to start the engine in deep water, you could pull some up.

The concern over dirt is overblown. I've run four-strokes with open breathers for decades, many of which were made of clear tubing, and no dirt ever makes it past the first few inches of hose.

  • grayracer513

Posted February 28, 2007 - 09:15 AM

#7

I spoke with the supermoto team manager at Mach 1 motorsports a week or so ago, and he told me they would be coming out with an oil breather containment/recapture setup in a couple months. Not only will it recapture oil that would have been lost through the breather, but it somehow lowers crankcase pressure and they have gained 1 1/2 horsepower with the setup


If it has a one way check valve on it to prevent any inflow through the hose, it could slightly lower crankcase pressure, but certainly not very much at speed. Some drag racers have fooled around with systems using a breather terminating in an angle cut fitting in the end of the exhaust outlet with the intent of creating a vacuum within the crankcase. These have been marginally effective, but drag races are won by marginal amounts of time.

I very seriously doubt the claim of a 1.5 hp gain by this.

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  • Ranger18

Posted February 28, 2007 - 11:21 AM

#8

[quote name='grayracer513']If it has a one way check valve on it to prevent any inflow through the hose, it could slightly lower crankcase pressure, but certainly not very much at speed. Some drag racers have fooled around with systems using a breather terminating in an angle cut fitting in the end of the exhaust outlet with the intent of creating a vacuum within the crankcase. These have been marginally effective, but drag races are won by marginal amounts of time.

I very seriously doubt the claim of a 1.5 hp gain by this.[/QUOTE]

I agree.
A question for you gray!! Not that I'm concerened about this topic, but could you plug the end of the hose like the hondas do? Then just drain it every oil change.

  • grayracer513

Posted February 28, 2007 - 11:59 AM

#9

A question for you gray!! Not that I'm concerened about this topic, but could you plug the end of the hose like the hondas do? Then just drain it every oil change.

Unless you also T the hose like the Honda, you can't plug it. Blocked breathers are the primary cause of the OEM decompression plugs being blown out, and the engine can and will push out the half moon seals in the cam cover. If it's T'd, you could do that, but there's very little reason to.

  • Joe_Jet

Posted February 28, 2007 - 12:54 PM

#10

I cut mine and put a large fuel filter on it. It sits behind the top of my Lightspeed glideplate just above the oil dipstick. I replace the filter every 10 hours as it does suck dirt and the flow gets slightly restricted. It looks very sano!

  • Twig323

Posted February 28, 2007 - 01:37 PM

#11

Yes i was asking because of water crossings. Its happened to people I know. Thanks for the input. Ill put a T on it.

  • yama02yz250f

Posted February 28, 2007 - 01:41 PM

#12

i was told from people on here to just run it into the airbox..that i didnt need to T it? is what i did ok? I think it was av's website that i got it from..minhe is for an 02

  • grayracer513

Posted February 28, 2007 - 03:34 PM

#13

You don't have to. But trust me, it works better if you do. You'll have less oil in the air box, for one thing. For another, the air box, especially in an '06+, is not the cleanest spot in the world. Routing the breather into the air box as a single line also shortens it, and lays it on the horizontal, both of which make it more likely, rather than less, to draw fine dirt into the engine. The use of a T reduces the air velocity to half what it originally was in both of the hoses connected to it, assuming they are of equal sizes.

  • yama02yz250f

Posted February 28, 2007 - 05:11 PM

#14

i always trust you gray! where did you get the T and hose? just form any hardware store im assuming.

  • grayracer513

Posted March 01, 2007 - 06:51 AM

#15

I would look at an auto parts hose. They have a wide variety of stuff like that for emissions plumbing. It's what I used on a couple of WR's for a friend of mine.





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