How to: Crankcase Vent Mod. - Page 2 - Kawasaki ZX-10R.net
 3Likes
Reply
 
LinkBack Thread Tools Display Modes
post #11 of 143 Old 09-22-2009, 03:14 PM
Champion Rider
 
Join Date: Apr 2009
Posts: 477
Posting Frequency
 
Quote:
Originally Posted by zxbrian10r View Post
the reed valves only open and suck in air on deceleration, to burn off extra unburnt fuel when you shut the throttle down, when you are cruising or at full throttle the system is shut down so exhaust wont go up threw the system, so by doing this mod you will be sealing your crankcase at cruising and full throttle runs, this is very bad for horsepower and will probable blow some oil seals quickly. examine how the reed valve works!!
im no expert!but the reed valves were being opened by the ais servo pumping air trough fron air box down into exhaust ports? when the sensor detected closed trottle?so now the reeds air seing crankcase pressure at all times they will be constantly open???
krakers10r is offline  
Sponsored Links
Advertisement
 
post #12 of 143 Old 09-22-2009, 03:47 PM
Street Rider
 
Join Date: Feb 2009
Location: dunedin florida
Posts: 90
Posting Frequency
 
they work on vacuum, inside if your reed there is a one way valve that lets air in but not out. under that are holes that go directly to your exhaust ports. so at high throttle openings or cruising the reeds are pressurized by exhaust gas, closing the system. when you chop the throttle the exhaust pressure suddenly drop's. using the Venturi effect the exhaust port sucks in air threw the reed valve from the airbox. if you start the bike and remove this hose, you can here it sucking at idle, the noise suddenly stops when revved. the mild pressure of the crankcase will not overcome the extreme pressures of the exhaust at the port.
zxbrian10r is offline  
post #13 of 143 Old 09-22-2009, 04:48 PM
GP Star
 
phastone's Avatar
 
Join Date: May 2004
Location: i
Posts: 2,976
Posting Frequency
  
Like Vince10R said; engines this size simply don't make enough vacuum to make any difference. This has been argued about ever since the '90s on pretty much every bike forum there is and no one can come up with any consistant, repeatable data that shows it really does anything.
phastone is offline  
 
post #14 of 143 Old 09-22-2009, 04:50 PM
Street Rider
 
Join Date: Feb 2009
Location: dunedin florida
Posts: 90
Posting Frequency
 
this is also why you find race teams with simple block off plates. i spoke to someone on attack kawasakis crew when i was at road Atlanta 2009. i was having an issue of oil pumping up into my airbox threw this breather tube due to my hi compression pistons and blow by. he told me that they remove the breather from the airbox. all it does is pump lots of extremely hot dirty air into your airbox at full throttle, this is not what your engine wants for good horse power, but it must be done this way for emissions. cant have oily blow by just leaking into the air. so he told me that they block the airbox hole and simply route this hose somewhere on the bike where they set up a catch pan for the oil that comes out. or they just simply use a crankcase filter on the top of the engine. that's what they do to there top level AMA bikes. if you go to maxton mile you will here of people roughing there breather into a catch also.
zxbrian10r is offline  
post #15 of 143 Old 09-22-2009, 05:52 PM Thread Starter
GP Rider
 
TENN10's Avatar
 
Join Date: Aug 2008
Location: Middle TN
Posts: 1,688
Posting Frequency
Images: 145
   
Quote:
Originally Posted by zxbrian10r View Post
they work on vacuum, inside if your reed there is a one way valve that lets air in but not out. under that are holes that go directly to your exhaust ports. so at high throttle openings or cruising the reeds are pressurized by exhaust gas, closing the system. when you chop the throttle the exhaust pressure suddenly drop's. using the Venturi effect the exhaust port sucks in air threw the reed valve from the airbox. if you start the bike and remove this hose, you can here it sucking at idle, the noise suddenly stops when revved. the mild pressure of the crankcase will not overcome the extreme pressures of the exhaust at the port.
Of course the exhaust pressure drops when you close the throttle. Not looking for gains at this point anyway.

I don't believe the system ever completely closes though. I am glad you bring this up. This is not something that I am 100% certain of so lets test it out. I will see if I can find something to measure the vacuum on with the throttle open and closed. If I can't come up with a cfm, I will at least test this using a vacuum gauge with a controlled leak for now.

I have been doing this mod. for over 8 years now. I've logged a ton of miles on different bikes with no negetive effects. Nor have I heard of any. I have heard of and seen small gains. I may make some back to back dyno runs one day, but I doubt any time soon. I've been there, done that honestly.

Just sharing info.
TENN10 is offline  
post #16 of 143 Old 09-22-2009, 06:02 PM Thread Starter
GP Rider
 
TENN10's Avatar
 
Join Date: Aug 2008
Location: Middle TN
Posts: 1,688
Posting Frequency
Images: 145
   
Quote:
Originally Posted by zxbrian10r View Post
this is also why you find race teams with simple block off plates. i spoke to someone on attack kawasakis crew when i was at road Atlanta 2009. i was having an issue of oil pumping up into my airbox threw this breather tube due to my hi compression pistons and blow by. he told me that they remove the breather from the airbox. all it does is pump lots of extremely hot dirty air into your airbox at full throttle, this is not what your engine wants for good horse power, but it must be done this way for emissions. cant have oily blow by just leaking into the air. so he told me that they block the airbox hole and simply route this hose somewhere on the bike where they set up a catch pan for the oil that comes out. or they just simply use a crankcase filter on the top of the engine. that's what they do to there top level AMA bikes. if you go to maxton mile you will here of people roughing there breather into a catch also.
When testing this before we ran this idea past an Attack crew member. Not gonna name drop, but this is not a "legal" mod. for racing.

Removing the Crankcase vent hose from the airbox is definately a good idea as long as you contain the oil of course.
TENN10 is offline  
post #17 of 143 Old 09-22-2009, 06:13 PM Thread Starter
GP Rider
 
TENN10's Avatar
 
Join Date: Aug 2008
Location: Middle TN
Posts: 1,688
Posting Frequency
Images: 145
   
Quote:
Originally Posted by phastone View Post
Like Vince10R said; engines this size simply don't make enough vacuum to make any difference. This has been argued about ever since the '90s on pretty much every bike forum there is and no one can come up with any consistant, repeatable data that shows it really does anything.
Very true. It's just a mod. that "I" do and I had time to document it so anyone interested could have a reference.

I'm not going argue the advantages or disadvantages of the mod. However, I am interested in intelligent info. that might lead me to learn something.

zxbrian10r makes a good point. If in fact the reeds do completely close, I wanna know. I don't "think" they do, but lets see.
TENN10 is offline  
post #18 of 143 Old 09-22-2009, 06:38 PM
GP Rider
 
Vince10R's Avatar
 
Join Date: Jan 2006
Location: Harleysville, Pa
Posts: 1,561
Posting Frequency
Images: 1
   
to all the guys talking about when the reed valve open and close I would have to think if i was even going to try something like this I would run a one way check valve(something like used in a car for the vacuum hose going to the brake booster) between the crancase vent and the valve cover tee(this will allow vacuum to be pulled on the crankcase but not allow pressure to feed back into it). then i would take the reed valves and remove the reeds(keeping everything else in the reed assembly but not the reeds, you will need this as it is the gasket for sealing it) so it will alway pull whenever there is high exhaust flow. Just the exhaust flowing past the tube extending into the exhaust will create the vacuum your looking for. Just like the old style as someone else mentioned that got welded to the collectors but with less volume which inturn will create less vacuum(negative pressure) in the crankcase
Vince10R is offline  
post #19 of 143 Old 09-22-2009, 06:41 PM Thread Starter
GP Rider
 
TENN10's Avatar
 
Join Date: Aug 2008
Location: Middle TN
Posts: 1,688
Posting Frequency
Images: 145
   
Quote:
Originally Posted by MagicMavis View Post
Actually we did once have something working back in the early 90's but not using the reed valves. We welded a one way check valve (made by NAPA) into the exhaust between the collector and muffler and as the exhaust gases rushed out the cannister the negative force pulled open the 1 way check valve which was connected to the crankcase breather placing a vacum draw onto the crankcase. It was good for 2-3 HP on every engine we did it. We did about 10 of those as I recall.

But that involved welding a steel part onto a steel pipe (most pipes were steel back then).


I don't see how this scheme using the reed valves would work. Seems like under hard acceleration the reed valves would be closed, only open under decell so I fail to see how that would improve anything.
However the concept of improving negative crankcase pressure is sound. All NASCAR engines use a pump to suck it out. They have done that for a long time.

I'm thinking this could be tested on my stands using RPM's as opposed to acceleration under a load?
TENN10 is offline  
post #20 of 143 Old 09-22-2009, 06:58 PM Thread Starter
GP Rider
 
TENN10's Avatar
 
Join Date: Aug 2008
Location: Middle TN
Posts: 1,688
Posting Frequency
Images: 145
   
Quote:
Originally Posted by Vince10R View Post
to all the guys talking about when the reed valve open and close I would have to think if i was even going to try something like this I would run a one way check valve(something like used in a car for the vacuum hose going to the brake booster) between the crancase vent and the valve cover tee(this will allow vacuum to be pulled on the crankcase but not allow pressure to feed back into it). then i would take the reed valves and remove the reeds(keeping everything else in the reed assembly but not the reeds, you will need this as it is the gasket for sealing it) so it will alway pull whenever there is high exhaust flow. Just the exhaust flowing past the tube extending into the exhaust will create the vacuum your looking for. Just like the old style as someone else mentioned that got welded to the collectors but with less volume which inturn will create less vacuum(negative pressure) in the crankcase
Good idea.

I was thinking along the same line of maybe removing the reeds if they actually close, but I need to get in there and understand more about how they work.

A check valve may be a good idea, but I would want some sort of very low pressure relief for this application.
TENN10 is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Kawasaki ZX-10R.net forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in











Currently Active Users Viewing This Thread: 3 (0 members and 3 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may post new threads
You may 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 Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome