Pair Block Off Mod

[Silverbird2]

Okay, I know that this has been done to death but I have searched and read different opinions on how this should be done. I have mine apart and plates on. I have all the unTT-necessary plumbing remove and the stub in the airbox plugged. The question is what to do with the one going from the top of the valve cover to the airbox? Remove and plug, re-route and plug airbox, or hook it back up?

[Hobicus]

Okay, I know that this has been done to death but I have searched and read different opinions on how this should be done. I have mine apart and plates on. I have all the unTT-necessary plumbing remove and the stub in the airbox plugged. The question is what to do with the one going from the top of the valve cover to the airbox? Remove and plug, re-route and plug airbox, or hook it back up?

That's not part of the PAIR system, that's just a vent for the valve cover. Hook it back up. It's purpose is to remove any gasoline fumes that get by the valves/etc from the oil, to keep your oil from thinning out.

[Silverbird2]

Okay, I know that this has been done to death but I have searched and read different opinions on how this should be done. I have mine apart and plates on. I have all the unTT-necessary plumbing remove and the stub in the airbox plugged. The question is what to do with the one going from the top of the valve cover to the airbox? Remove and plug, re-route and plug airbox, or hook it back up?

That's not part of the PAIR system, that's just a vent for the valve cover. Hook it back up. It's purpose is to remove any gasoline fumes that get by the valves/etc from the oil, to keep your oil from thinning out.

I realize that it is not part of the PAIR system but i read where some people said to hook it back and some said don't.

By the way Hobie thank for the prompt responce and delivery of the block off plates. I got them much faster than i had expected. Anyone needing a set Hobie is your man. Painless transaction. :icon_thumbsup:

[EVLXX]

Hook it back up.

[cbrxxquad]

This also pulls vacuum on the crankcase to prevent oil foaming, oil brake, IE allows the oil to fall out. The more the better vacuum.

Bill Grumpy Jenkins was able to add as much as 25hp to a small block Chevy by also adding a pitot tubes to the exhaust and also connecting to the crankcase evacuation system. Now they add a vacuum pump to pro-stock engines to maintain good vacuum. Proper seals and sealing is mandatory.

[tomek]

Just becouse I like to open can of worms,,, point could be made that in Ram Air system crankase vent can actually increase pressure in high speed riding,,,,,,,no vacum at all in air box,Sport Rider ran some tests years ago,at 170 mph pressure in airbox was about 5% higher then atmosheric.

It does not take a genius to marry crankase vent with PAIR system,you just need to disable/bypass solenoid, reed valves are already there,,,,,,,.

Some Suzuki AMA teams ( Jordan) were running that in Superstock but AMA called that illegal,they got DQed.

I had to remove my exhaust header a week or two ago in order to replace oil pan ,after 37k miles ports and pipes looked normal,no heavy carbon deposits.

[EVLXX]

So you're saying..... one should hook up the Pair system to the Valve cover crankcase breather....

with No filter ?

And your Not measuring or Care about AFR's right ?

Just becouse I like to open can of worms,,, point could be made that in Ram Air system crankase vent can actually increase pressure in high speed riding,,,,,,,no vacum at all in air box,Sport Rider ran some tests years ago,at 170 mph pressure in airbox was about 5% higher then atmosheric.

It does not take a genius to marry crankase vent with PAIR system,you just need to disable/bypass solenoid, reed valves are already there,,,,,,,.

Some Suzuki AMA teams ( Jordan) were running that in Superstock but AMA called that illegal,they got DQed.

I had to remove my exhaust header a week or two ago in order to replace oil pan ,after 37k miles ports and pipes looked normal,no heavy carbon deposits.

Interesting... but now that I think about it... I think I Do need to put a Check valve in the crankcase breather line to the air-box if there is not already one there...........

That way I still get the Benefits of Vacuum to the Case, No Exhaust contamination or dilution, and No pressure in the case, and as Stan pointed out for better Oil stability.

..... Thanks.

Just for Clarification... in my opinion, Block off PAIR = Good. Block of Crankcase Breather = Bad.

[tomek]

So you're saying..... one should hook up the Pair system to the Valve cover crankcase breather....

with No filter ?

And your Not measuring or Care about AFR's right ?

Just becouse I like to open can of worms,,, point could be made that in Ram Air system crankase vent can actually increase pressure in high speed riding,,,,,,,no vacum at all in air box,Sport Rider ran some tests years ago,at 170 mph pressure in airbox was about 5% higher then atmosheric.

It does not take a genius to marry crankase vent with PAIR system,you just need to disable/bypass solenoid, reed valves are already there,,,,,,,.

Some Suzuki AMA teams ( Jordan) were running that in Superstock but AMA called that illegal,they got DQed.

I had to remove my exhaust header a week or two ago in order to replace oil pan ,after 37k miles ports and pipes looked normal,no heavy carbon deposits.

Interesting... but now that I think about it... I think I Do need to put a Check valve in the crankcase breather line to the air-box if there is not already one there...........

That way I still get the Benefits of Vacuum to the Case, No Exhaust contamination or dilution, and No pressure in the case, and as Stan pointed out for better Oil stability.

..... Thanks.

Just for Clarification... in my opinion, Block off PAIR = Good. Block of Crankcase Breather = Bad.

Clarification,,,I`m not disputing benefits of the vacum in crankcase,higher-the better, it is no brainer.

Why whould real AFR change ? In stock configuration blowby gases go into airbox and dilute fresh charge, but in healthy engine with very good piston/cylinder seal that is irrelevent,I`m just routing them into exhaust headers,so it does not matter,crank case breather is not blocked.PAIR system has reed plates/valves,gases can go only one way.It is my ghetto version of proper crankcase vacum system that is using exhaust scavenging effect.

Like I`ve said,I put 37 k miles with above explained system,no oil consumption,no engine leaks,no carbon build up in pipes or ports.In shitty motor it might create problems,but I don`t have any.

BTW,I`ve done the same thing in my R1.

[Silverbird2]

Very interesting, I am glad i asked.

[cbrxxquad]

I think I remember you and I talking about this at Ozarxx Tomek, but I forgot a lot of that weekend. :icon_silenced:

Yes that is a very good idea, and would not change the afr. Vacuum in the crankcase helps the rings seal better and would have less fuel in the oil with better seal.

Would also pressure the airbox better.

Did you do any measurements on crankcase pressures or vacuums?

Wonder if my lm1 would record any difference at the map sensor with the difference in the plumbing?

Need to pull the tank anyway, cruise did not work..wonder what I did wrong..

[EVLXX]

So you're saying..... one should hook up the Pair system to the Valve cover crankcase breather....

with No filter ?

And your Not measuring or Care about AFR's right ?

Just becouse I like to open can of worms,,, point could be made that in Ram Air system crankase vent can actually increase pressure in high speed riding,,,,,,,no vacum at all in air box,Sport Rider ran some tests years ago,at 170 mph pressure in airbox was about 5% higher then atmosheric.

It does not take a genius to marry crankase vent with PAIR system,you just need to disable/bypass solenoid, reed valves are already there,,,,,,,.

Some Suzuki AMA teams ( Jordan) were running that in Superstock but AMA called that illegal,they got DQed.

I had to remove my exhaust header a week or two ago in order to replace oil pan ,after 37k miles ports and pipes looked normal,no heavy carbon deposits.

Interesting... but now that I think about it... I think I Do need to put a Check valve in the crankcase breather line to the air-box if there is not already one there...........

That way I still get the Benefits of Vacuum to the Case, No Exhaust contamination or dilution, and No pressure in the case, and as Stan pointed out for better Oil stability.

..... Thanks.

Just for Clarification... in my opinion, Block off PAIR = Good. Block of Crankcase Breather = Bad.

Clarification,,,I`m not disputing benefits of the vacum in crankcase,higher-the better, it is no brainer.

Why whould real AFR change ? In stock configuration blowby gases go into airbox and dilute fresh charge, but in healthy engine with very good piston/cylinder seal that is irrelevent,I`m just routing them into exhaust headers,so it does not matter,crank case breather is not blocked.PAIR system has reed plates/valves,gases can go only one way.It is my ghetto version of proper crankcase vacum system that is using exhaust scavenging effect.

Like I`ve said,I put 37 k miles with above explained system,no oil consumption,no engine leaks,no carbon build up in pipes or ports.In shitty motor it might create problems,but I don`t have any.

BTW,I`ve done the same thing in my R1.

Tomek,

If the PAIR system is hooked up to the Case Breater, How does the Case get it's air ?

By the way... I'm totally shooting in the dark here, it's been over a year since I looked at this motor close up, so yes I really am asking. (the air has to come from somewhere, the Case cannot be in a vacum state all the time)

But back to my point, If the Pair system is hooked up to anything and can pull oxygen from that source, then it will contaminate the reading on a Oxygen Sensor if one is installed in the exhaust system.

So... if and only if, you want accurate AFR reading, either from the Dyno shop, or from a Dattalogger of some sort. You have to block off the PAIR system completely.

If on the Other hand, you don't care about the AFR reading, then I see nothing wrong with hooking the PAIR system up to the Case Breather.

Very interesting, I am glad i asked.

Don't ya just Love it.

I think I remember you and I talking about this at Ozarxx Tomek, but I forgot a lot of that weekend. :icon_silenced:

Yes that is a very good idea, and would not change the afr. Vacuum in the crankcase helps the rings seal better and would have less fuel in the oil with better seal.

Would also pressure the airbox better.

Did you do any measurements on crankcase pressures or vacuums?

Wonder if my lm1 would record any difference at the map sensor with the difference in the plumbing?

Need to pull the tank anyway, cruise did not work..wonder what I did wrong..

Well you, with 2 motors to look at, will be the best to answer this quickly....

How will the Crankcase get AIR if not from the Valve Cover Breather Tube ? Is there another opening somewhere ?

Does thins open, if it has one, have a filter on it ?

Rings Seal upon combustion, and do a poor job of sealling at BDC, and on the Intake stroke. So I wonder... if there is No other way for the Case to pull air into it, then it's going to have to wash by the rings, during these 2 events, or it's going to have to be drawn buy a Rubber Seal somwhere, and since most Seals are designed to hold Oil in. they are poor at keeping Air out, especially under a Vacum....

So.... I wonder.

[cbrxxquad]

Ok, the breather tube that goes from the valve cover to the air cleaner would be split into two lines and routed to the two pair tubes, and the reeds under the cover only allow air to be pulled through them with gas velosity in the exhaust. High gas flow by holes that are piped to the reeds go through the head create vacumn, on the crankcase. Only air or gas is from blow by rings. But low pressure helps the rings seal better thus less flow.

Also, the hole in the air cleaner that the breather hose went to needs to be plugged.... der.

Better ????

Yes, the seals in the engine need to be good for,, as Grumpy said 27 inches vacumn,at full rpm closed throttle.

[EVLXX]

Ok, the breather tube that goes from the valve cover to the air cleaner would be split into two lines and routed to the two pair tubes, and the reeds under the cover only allow air to be pulled through them with gas velosity in the exhaust. High gas flow by holes that are piped to the reeds go through the head create vacumn, on the crankcase.

I knew all that....

this was what I was unsure about.

Only air or gas is from blow by rings.

As for this...

But low pressure helps the rings seal better thus less flow.

Also, the hole in the air cleaner that the breather hose went to needs to be plugged.... der.

Better ????

Yes, the seals in the engine need to be good for,, as Grumpy said 27 inches vacumn,at full rpm closed throttle.

I agree that the Lower internal pressure would help the rings seal, and it create a lower pumping mass behind the pistons, hence the increased power.

Still my only concern is still for the Seals..... at a supposed 27 inches of Vacuum, the increased wear rate of the seal itself would be my worry. If it was a race bike.... I'd do it in a second, but for a daily Rider..... I don't know.... let see, after 6 years, and never having an oil leak.... I'd say Static crankcase pressure is just fine with me.

Another thought comes to mind..... Oiling of the Valve Guides.... I wonder what pulling a Vacuum on the Case has to due with the flow rate of Oil down the valve guides.....

Like I said... If it was a Race bike.... I'd have it done in a second, but for me.... I wouldn't do it on my Daily Ride.

...

Funny really, this all coming from the guy who thinks 17:1 is fine at 4K rpm.... Hehe. Here I am worried about Oil Seals and Valve guides..... Go figure.

[Silverbird2]

Here's one that i have not heard before:

This seems to be a popular set of questions over here at Graves Motorsports. Most people tell me “they don’t make any horsepower so why should I spend the $35 and take the time to install them”.

Here is a quick but complete explanation on the benefits of using the pair valve block off plates on just about every model motorcycle.

*This is for off road racing applications and not meant to be used on the street.

If you have something to add please feel free.

From the factory most motorcycles will come with a pair valve system on them. This is basically an air pump that pulls fresh air from your air box and through a bunch of hoses and fittings it pumps that fresh air into your exhaust ports on your cylinder head and sends it through your exhaust

There is unburned fuel that makes it through the combustion stroke, exits the cylinder head, and makes its way down the exhaust system to finally exit into the atmosphere. The pair valve system adds fresh O2 to the exhaust so that as the unburned fuel come into contact with the extremely hot catalytic converter, the additional fresh air will cool the exhaust and aerate the fuel for a more efficient burn. This equals less emissions being released. Plus the additional O2 in the exhaust the lower the emissions reading. I have heard a number of reasons this is done but I will stick with the basic theories that I am aware of.

(1) This requires a catalytic converter to really complete its job. Once you have installed a full race system and have removed the cat, all this fresh air will do it

create the popping and back firing that throws those incredibly cool but damaging flames out of your exhaust .Great for night riding, but terrible for tail sections and leg hairs. To eliminate this add the smog block off plates.

(2) If you decide to have your bike dyno tuned then you cannot run the pair valve system because as it adds oxygen to the exhaust. The dyno “sniffer” is picking up false readings from the additional O2 added after combustion. When it reads the extra O2 it thinks the bike is running lean and will compensate by adding fuel to the fuel map. Now you have a map that is much fat (too much fuel) and the bike will run terrible. The person that is tuning the bike will have to pinch these off every time you dyno the bike. To eliminate this add the smog block off plates.

(3) The tubes, pump, and wires that are included in the pair valve smog system add unnecessary clutter and weight to the motorcycle. To eliminate this add the smog block off plates.

(4) This is the last reason I have found to run the plates but it is NOT A FACT. It seems only I have noticed this and nobody has proven it right or wrong so do not take this as absolute. It could very well be just by brain acting up.

I believe I felt it help my engine breaking a little. Before I installed them I felt like the bike (08 R6) had a really strong engine breaking and would pop and back fire a lot on

de-acceleration. When I installed the plates I would swear that the engine breaking became more suitable. It was not as abrupt and not nearly as strong. Again this was only a guess and has no proof to it, however I did talk amongst a few tech savvy buddies and we worked out a somewhat scientific theory. Possibly as the hot engine gases are pouring smoothly out of the cylinder head like melted butter this cold fresh oxygen is forced into the exhaust ports. This could very well slow those gases down and create more back pressure which in theory could possibly cause stronger engine breaking. So…..maybe Im not crazy.

[elm327]

i got a carbed yammy v star cruiser, i put pipes on it and jetted and had a pop on decelleration. it was annoying! i removed its pair valve and the pop on decel was gone.also same deal on yammy wr 450 dirtbike same smog crap. it had annoying pop on decel bone stock, removed the valve and it was gone!

[cbrxxquad]

Grumpy's system uses one check valve to go from the valve cover to the mainfold under the carb, and another check valve to go from the piot tubes in the exhaust to the valve cover on the other side...

might do the same on ours.,,,,,hummmm to conect to the vacumn lines under the butterflys..instead of the aircleaner.

Gotta sleep on it.

The seals on ours are good, the ones on the SBC in the front and end of the manifold are junk, use silicone to seal the whole thing instead of the rubbers...valve seals don't see the vacumn, and it is only under closed butterflys.

[EVLXX]

(4) This is the last reason I have found to run the plates but it is NOT A FACT. It seems only I have noticed this and nobody has proven it right or wrong so do not take this as absolute. It could very well be just by brain acting up.

I believe I felt it help my engine breaking a little. Before I installed them I felt like the bike (08 R6) had a really strong engine breaking and would pop and back fire a lot on

de-acceleration. When I installed the plates I would swear that the engine breaking became more suitable. It was not as abrupt and not nearly as strong. Again this was only a guess and has no proof to it, however I did talk amongst a few tech savvy buddies and we worked out a somewhat scientific theory. Possibly as the hot engine gases are pouring smoothly out of the cylinder head like melted butter this cold fresh oxygen is forced into the exhaust ports. This could very well slow those gases down and create more back pressure which in theory could possibly cause stronger engine breaking. So…..maybe Im not crazy.

Correct.

When the PAIR system injects Cool fresh air into the system, it drop the temp of the exhaust, which slows the Flow, which in turn raises the Backpressure of the system, which increases Engine Brakeing.

More Backpressure = More Engine Braking

Less Backpressure = Less Engine Braking

[BackStreet]

The Earth's atmosphere (or air) is a thin layer of gases surrounding the planet Earth that is retained by the Earth's gravity. Fifty percent of the total mass of the atmosphere is located in the lower 18,000 ft or 3.4 miles of the troposphere compared to the almost 8,000 mile diameter of the earth.

The point is we live in a very thin layer of air. The PAIR system is an effective way to reduce pollution at no cost is in fuel or horsepower.

If you are getting your bike dyno tuned, a simple clamp can temporary block off the system if needed. It is not like you dyno tune every week.

We can all live with the PAIR system. Motorcycles don't want to end up in the EPA cross hairs for pollution control or reduction.

Also, from the EPA web site, any person may face fines up to $3,750 per vehicle for tampering with emission controls after Jan 12, 2009.

Under Section 205(a) of the Act, 42 U.S.C. 8 7524(a), the maximum penalty for violations of the vehicle and engine requirements under Title I1 of the Act is $25,000 per vehicle or engine, with two exceptions.The maximum penalty for violations of the tampering prohibition when committed by any person other than a manufacturer is $2,500 per vehicle, and the maximum penalty for violations of the defeat device prohibition is $2,500 per device. These maximum penalty amounts were increased from $25,000 to $32,500 and from $2,500 to $2,750 for violations occurring after March 15, 2004, through January 12,2009, and to $37,500 and $3,750 for violations occurring thereafter

[jon haney]

I don't know what you're talk'n about. I bought the bike that way! :icon_shhh: :icon_shifty:

[cbrxxquad]

So if we pump a bunch of air in the exhaust can we run it really rich. Same idea, dumb. The bike is rich to the point of running bad from the factory. The pair only covers the problem up by faulting the reading. Not doing any thing for the enviroment at all.

Now using it to pull the crankcase pressure down and causing the rings to seal better and prevent raw fuel from getting past and into the oil and atmosphere unburned. And gettin the power from it. Now that is logical. Last thing they would want right?

Lame.

[EVLXX]

Anybody that believes the Fecal material posted in this quote section......

The Earth's atmosphere (or air) is a thin layer of gases surrounding the planet Earth that is retained by the Earth's gravity. Fifty percent of the total mass of the atmosphere is located in the lower 18,000 ft or 3.4 miles of the troposphere compared to the almost 8,000 mile diameter of the earth.

The point is we live in a very thin layer of air. The PAIR system is an effective way to reduce pollution at no cost is in fuel or horsepower.

If you are getting your bike dyno tuned, a simple clamp can temporary block off the system if needed. It is not like you dyno tune every week.

We can all live with the PAIR system. Motorcycles don't want to end up in the EPA cross hairs for pollution control or reduction.

Also, from the EPA web site, any person may face fines up to $3,750 per vehicle for tampering with emission controls after Jan 12, 2009.

Under Section 205(a) of the Act, 42 U.S.C. 8 7524(a), the maximum penalty for violations of the vehicle and engine requirements under Title I1 of the Act is $25,000 per vehicle or engine, with two exceptions.The maximum penalty for violations of the tampering prohibition when committed by any person other than a manufacturer is $2,500 per vehicle, and the maximum penalty for violations of the defeat device prohibition is $2,500 per device. These maximum penalty amounts were increased from $25,000 to $32,500 and from $2,500 to $2,750 for violations occurring after March 15, 2004, through January 12,2009, and to $37,500 and $3,750 for violations occurring thereafter

Sorry, but just because some knothead EPA nut,(or even a group of them), says it good for the Environment.... isn't necessarily true. In fact, it maybe nothing more than an attempt to Scare you into believe that they are smarter than you.

Sadly enough.... a-lot of the time it works.

.......

The below... couldn't be more true....

So if we pump a bunch of air in the exhaust can we run it really rich. Same idea, dumb. The bike is rich to the point of running bad from the factory. The pair only covers the problem up by faulting the reading. Not doing any thing for the enviroment at all.

Now using it to pull the crankcase pressure down and causing the rings to seal better and prevent raw fuel from getting past and into the oil and atmosphere unburned. And gettin the power from it. Now that is logical. Last thing they would want right?

Lame.

...... OH well, I hope this thread Learnd somebody somnin guud.

[Silverbird2]

This actually turned out to be one of the better PAIR threads

[jon haney]

So if we pump a bunch of air in the exhaust can we run it really rich. Same idea, dumb. The bike is rich to the point of running bad from the factory. The pair only covers the problem up by faulting the reading. Not doing any thing for the enviroment at all.

Now using it to pull the crankcase pressure down and causing the rings to seal better and prevent raw fuel from getting past and into the oil and atmosphere unburned. And gettin the power from it. Now that is logical. Last thing they would want right?

Lame.

+1

I'm glad I'm not the only one who thinks most emission control crap only fools the sniffers.

[BackStreet]

So if we pump a bunch of air in the exhaust can we run it really rich. Same idea, dumb. The bike is rich to the point of running bad from the factory. The pair only covers the problem up by faulting the reading. Not doing any thing for the enviroment at all.

Now using it to pull the crankcase pressure down and causing the rings to seal better and prevent raw fuel from getting past and into the oil and atmosphere unburned. And gettin the power from it. Now that is logical. Last thing they would want right?

Lame.

+1

I'm glad I'm not the only one who thinks most emission control crap only fools the sniffers.

+2

Yes, it's a big plan with all the oil companies to push more gas through motorcycles so they burn as much as cars.

[tomek]

Well,low emmision regulations for commercial on highway diesel trucks killed fuel economy to the tune of 5-15 %.Price of those trucks increased by good couple of grand too.Those engines run EGR, cat converters,needed new spec oils,dealers need special aparatus to clean exhaust filters.Bigger radiators,longer chassis to find the place of all that crap,etc.

Lesser fuel economy means higher demand,(wonder why diesel is now more expensive then even premium when years ago was cheaper ?),that means more fuel has to be refined,delivered,pumped,etc so at the end those new rules hardly "save environment".