Using the PAIR valves as a crankcase evacuation system - SV1000 Portal
 4Likes
Reply
 
LinkBack Thread Tools Rate Thread Display Modes
post #1 of 71 (permalink) Old 14th October 2014, 09:49 AM Thread Starter
KNEE DRAGGER
 
schmidt314's Avatar
 
Join Date: Nov 2005
 ♂ United States
Portland Oregon
Posts: 5,043
Garage
Using the PAIR valves as a crankcase evacuation system

Lots of questions came up after a post I made about plumbing the PAIR valves into the crankscase vent to evacuate and create a vacuum internal to the engine.

Why do some thing like this? Well, on a 90 degree V twin as the crank spins, the internal volume of the engine changes significantly. The engine is also pumping air under the pistons back and forth to each other, and in and out of the engine. There are also basic aerodynamic principal at work too. The crank and rods and tranny are all spinning around in the engine pushing air around with it. This is drag added to the engine which takes power.

Conventional crank I4s do not change crank case volume during an engine revolution, but they still pump the air from under the piston back and forth and cause internal losses. We used to actually make cut outs between cylinders when we using ZX11 engines long ago for the F1 sidecars. It made a difference. This is why also many manufactures are cutting out the cylinder sleeves between adjacent cylinder, they want to get rid of internal pumping losses. I included a picture of a set of OEM GENII Hayabusa cylinders to show what I am talking about.

Next thing to talk about is the PAIR valves. How do they work? Well simply put, Bernoulli's priciple of high velocity air creates a low pressure region. The PAIR valves do exactly this. As the high speed exhaust gas goes by the hole in the exhaust port it creates low pressure that gets channeled through the reed valves in the head and up to PAIR valve control solenoid. When the solenoid opens, it draws cool air form the air box and mixes it with the out going exhaust to burn unspent hydro carbons on the way out of the exhaust.

So why not use the vac created by the PAIR ports to pump out the crank cases to take advantage of the benefits described above. Here is how I have been doing it on the SV1000. Quick and easy. Pull the air box out and pull the PAIR control solenoid out, but leave the hoses that go to the front and rear cylinders. Bridge the electrical on the harness side of the bike that was plugged into the solenoid with a 1Kohm 1/2 watt resistor. I take the old plug, and use a couple of connector s and such and make a nice little plug unit to keep the FI light from coming on. Now scrounge up a T fitting such as the one shown in the image below. Now connect the upper part of the crank case vent hose you disconnected to remove the air box, to the T fitting. Now just plug in the front and rear PAIR hoses into the T. Remember to plug the port in the airbox when it goes back together. The bike will now pump on the crankcases as soon as the bike starts. As the exhaust gas speed goes up, the lower pressure seen in the crankcases.

I would pull out the reed valves under the plastic PAIR caps bolted to the valve covers, and clean them very well and make sure they are sealing well. A poorly sealing valve will not allow the bike to hold best possible vacuum.

I have set up many SV1000 and a whole bunch others. In my experience with the SV1000 oil consumption will not be an issue because the vents are well baffled, and if it were pumping oil through the vent, it would have originally been pushing it into the air box to get consumed anyway.

I do not have any direct dyno data for the SV1000, but I can assure you it will help. Lots of info out there on SV650s, Ducatis and tons of other race engines and vehicles. All of our race bikes I set up have been pumping on the crankcases for many years.

I did collect some data a couple of times to see what the pressure level was actually getting to in the crank cases, but I am not sure if I can find it any more.

You also have to remember to pull the oil fill cap before draining out our oil, or it just wont drain, because the cases are not vented due to the reeds being closed.

-MS
Attached Images
File Type: jpg Hayabusa_Cylinders.JPG (257.0 KB, 255 views)
File Type: jpg Parts.jpg (545.0 KB, 303 views)
File Type: jpg IMG_6031.jpg (436.7 KB, 360 views)
File Type: jpg IMG_6032.jpg (451.0 KB, 334 views)


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
schmidt314 is offline  
Sponsored Links
Advertisement
 
post #2 of 71 (permalink) Old 14th October 2014, 01:36 PM
Scooter boy
 
Jordan's Avatar
 
Join Date: Sep 2014
 ♂ United States
Posts: 52
Fantastic! Thanks. What is the size of that t fitting?

03 Blue naked. holeshot high mounts, -2 up front, corbin seat.check your tps.
Jordan is offline  
post #3 of 71 (permalink) Old 15th October 2014, 12:42 AM
Upside-Downer
 
RodBacon's Avatar
 
Join Date: Aug 2014
 ♂ Australia
Perth, Western Australia
Posts: 373
Can a mod please make this sticky?


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
  • 6000K HIDs, Tail Tidy, LED Indicators, TRE, PCIII, K&N Filter
  • Yoshimura 2-into-1, CR8EIX Plugs, Snorkel Prune, Carbon Hugger, Helibars, Oxford Hotgrips, Chrome Cooler Guards
  • Sharealike Clutch, Voltmeter, Usb Charge Port, Suzuki Gel Seat, Racetech Springs
RodBacon is offline  
 
post #4 of 71 (permalink) Old 16th October 2014, 07:12 AM
Knowledge is Horsepower
 
D.T.'s Avatar
 
Join Date: Jul 2005
 ♂ United States
Moneyapolis, MN
Posts: 3,259
Garage
Mine have Chewey's blanks.

I may give it a try for shits and giggles and see if oil consumption is a problem.
D.T. is offline  
post #5 of 71 (permalink) Old 16th October 2014, 05:58 PM
L-Plate Rider
 
Join Date: Jan 2013
 ♂ Canada
Oakville, ON, Canada
Posts: 14
This makes sense.

I would really like to see dyno data, though, and see how much of a difference it makes over the stock crank vent.
Gallow is offline  
post #6 of 71 (permalink) Old 16th October 2014, 06:31 PM
Knowledge is Horsepower
 
D.T.'s Avatar
 
Join Date: Jul 2005
 ♂ United States
Moneyapolis, MN
Posts: 3,259
Garage
Okay, I ran to the hardware store, got a 1/2" nylon hose barb tee and some 1/2" heater hose. Took off the blank plates, cleaned the reed valves and got it connected like Mike did.

Last ride to work this year (probably) so we will see how it works.

I remember using a small K&N filter on a crank vent once. Oil mist all over and the oil got dirty fast so I stopped doing it.
D.T. is offline  
post #7 of 71 (permalink) Old 16th October 2014, 08:56 PM
Hardcore Biker
 
xtremewlr's Avatar
 
Join Date: Sep 2009
 ♂ United States
Coronado, CA
Posts: 824
Quote:
Originally Posted by D.T. View Post
Okay, I ran to the hardware store, got a 1/2" nylon hose barb tee and some 1/2" heater hose. Took off the blank plates, cleaned the reed valves and got it connected like Mike did.

Last ride to work this year (probably) so we will see how it works.

I remember using a small K&N filter on a crank vent once. Oil mist all over and the oil got dirty fast so I stopped doing it.
Don't see that happening with this mod since the system is closed and the oil that does collect should drain back into the crankcase.

Gotta check to see if I kept the pair breathers when I installed Chewy's plates. Just did it fairly recently too. Wish Mike would have posted this sooner!
xtremewlr is offline  
post #8 of 71 (permalink) Old 16th October 2014, 09:49 PM Thread Starter
KNEE DRAGGER
 
schmidt314's Avatar
 
Join Date: Nov 2005
 ♂ United States
Portland Oregon
Posts: 5,043
Garage
Quote:
Originally Posted by xtremewlr View Post
Don't see that happening with this mod since the system is closed and the oil that does collect should drain back into the crankcase.

Gotta check to see if I kept the pair breathers when I installed Chewy's plates. Just did it fairly recently too. Wish Mike would have posted this sooner!
I have been doing this on SV1000 and 650 for ages now, just never told anybody about it really... Sorry
I still have a few more tricks up my sleeve too
-MS
twag4 likes this.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
schmidt314 is offline  
post #9 of 71 (permalink) Old 16th October 2014, 09:57 PM Thread Starter
KNEE DRAGGER
 
schmidt314's Avatar
 
Join Date: Nov 2005
 ♂ United States
Portland Oregon
Posts: 5,043
Garage
Quote:
Originally Posted by D.T. View Post
Okay, I ran to the hardware store, got a 1/2" nylon hose barb tee and some 1/2" heater hose. Took off the blank plates, cleaned the reed valves and got it connected like Mike did.

Last ride to work this year (probably) so we will see how it works.

I remember using a small K&N filter on a crank vent once. Oil mist all over and the oil got dirty fast so I stopped doing it.
It would really surprise me to see any different oil consumption than you have right now. As I had mentioned before in another post that prompted me start this thread, my race bike ran with this modification in an 8 hour endurance race without noticeable oil consumption.

It might actually cut down on oil consumption a tiny bit because it is no longer pushing massive amount of hot oily air out and then in at every revolution and exhausting into the air box for the mist to be consumed.

The bike might idle a bit higher too once a good vac has been pulled in the cases.

-MS


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
schmidt314 is offline  
post #10 of 71 (permalink) Old 16th October 2014, 11:47 PM
Fair weather rider
 
CHOPCHOP's Avatar
 
Join Date: Feb 2013
 ♂ Australia
Brisvegas
Posts: 101
You should only use oil if it is sucking air from somewhere. Apart from the initial creation of suction there should be little flow, provided there is enough of a pressure differential that piston movements are not dispelling air. As Mike said it should actually use less. You would also want to make sure the reed valves work effectively or you could flow air every time you drop rpm.

Last edited by CHOPCHOP; 17th October 2014 at 12:04 AM. Reason: brain death
CHOPCHOP is offline  
post #11 of 71 (permalink) Old 19th October 2014, 01:33 PM
Contributor
 
chewy22's Avatar
 
Join Date: Nov 2003
 ♂ United Kingdom
LAKE DISTRICT
Posts: 6,110
Think I will have a go at this on the winter strip down as it's very simple to do. I could easy put a small kit together on my site with full instructions so you could do it yourself if you don't want to buy the parts. If that's ok with you Mike

Think all I will need is a T piece fuel connecter, I have the right size blanks for the air box and the resisters.

Couple of questions , I take it this mod allows the engine to rev more freely removing internal pressure is that correct? Also would you gaining a little more power bhp, I imagine it will be tiny.

The reed valve only flows one way that would be flow from the air box originally, open and closed only when the pair pump was req, now you have them connected to the crank breather the reed valves (both) would open on every downward stroke? Is that correct.

I know it seems like a stupid question but if I put this on my site I will get the question in my in box and I need to be able to explain it in layman's terms.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
CHEWYS STUFF


SV996R

Last edited by chewy22; 19th October 2014 at 01:47 PM. Reason: To add more
chewy22 is offline  
post #12 of 71 (permalink) Old 19th October 2014, 02:04 PM
I love my SV
 
tonyt's Avatar
 
Join Date: Apr 2003
 ♂ United Kingdom
West Kent
Posts: 5,783
Quote:
Originally Posted by chewy22 View Post
Think I will have a go at this on the winter strip down as it's very simple to do. I could easy put a small kit together on my site with full instructions so you could do it yourself if you don't want to buy the parts. If that's ok with you Mike

Think all I will need is a T piece fuel connecter, I have the right size blanks for the air box and the resisters.

Couple of questions , I take it this mod allows the engine to rev more freely removing internal pressure is that correct? Also would you gaining a little more power bhp, I imagine it will be tiny.

The reed valve only flows one way that would be flow from the air box originally, open and closed only when the pair pump was req, now you have them connected to the crank breather the reed valves (both) would open on every downward stroke? Is that correct.

I know it seems like a stupid question but if I put this on my site I will get the question in my in box and I need to be able to explain it in layman's terms.
Sounds a good idea Chewy..
tonyt is offline  
post #13 of 71 (permalink) Old 19th October 2014, 03:55 PM
Hardcore Biker
 
xtremewlr's Avatar
 
Join Date: Sep 2009
 ♂ United States
Coronado, CA
Posts: 824
Quote:
Originally Posted by xtremewlr View Post
Gotta check to see if I kept the pair breathers when I installed Chewy's plates. Just did it fairly recently too. Wish Mike would have posted this sooner!
Well, looks like I tossed the pair breathers from both the SV650 and the SV1K so I'll have to see if I can find them on ebay now.
xtremewlr is offline  
post #14 of 71 (permalink) Old 20th October 2014, 04:24 AM
Forum whore
 
Join Date: Feb 2011
 ♂ United States
SW Pennsylvania, USA
Posts: 2,148
Quote:
Originally Posted by chewy22 View Post

Couple of questions , I take it this mod allows the engine to rev more freely removing internal pressure is that correct? Also would you gaining a little more power bhp, I imagine it will be tiny.

The reed valve only flows one way that would be flow from the air box originally, open and closed only when the pair pump was req, now you have them connected to the crank breather the reed valves (both) would open on every downward stroke? Is that correct.

I know it seems like a stupid question but if I put this on my site I will get the question in my in box and I need to be able to explain it in layman's terms.
The reed valves will open when the pistons are traveling downward and reducing the crankcase volume which will push air into the exhaust ports. Then when the pistons rise the next time the reeds will close and the expanding crankcase volume is what creates the negative pressure within. I've not given much thought to exactly when the exhaust pressures will go negative in the cycle as to where the pistons will be when this happens. The crankcase will experience negative pressures just from having the reed valves controlling the breathing thought the negative exhaust pressures could very well enhance the effect. Mine does the same thing with a one-way valve on the breather hose to the airbox...and it does make a difference in how the engine runs. The Ducati fellows were able to measure a several horsepower increase when they opened up the breathers on one of their race bikes...so it wouldn't surprise me if the SV gets a couple more too.
RecoilRob is offline  
post #15 of 71 (permalink) Old 20th October 2014, 04:34 AM
Hardcore Biker
 
falconbobb's Avatar
 
Join Date: Jun 2010
 ♂ United States
kentucky
Posts: 513
Hmm doesnt the big hose from the crankcase going to the airbox create vacuum in the case w/out the pair valves or solanoid in the system?
falconbobb is offline  
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the SV1000 Portal 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: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes Rate This Thread
Linear Mode Linear Mode
Rate This Thread:



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 Off
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On

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