Hi has anyone tried this mod to there zx 14 , that is running the engine breather through the exhaust emission plate on top of the valve cover

---

Sounds like you are talking a Positive Crankcase Ventilation system???

I considered it but was told it was not worth the trouble with this machine. The suction that could be scavenged off the PAIR is not enough to really matter.

Still interested in the idea but by now, I've learned to sit back and watch the crowd. The idea has been suggested but nobody is doing it. To me, that means skip it and concentrate on the tried and true.

---

hi rook i have done this after advise from my dyno tuner. i was suprised by the suction it created. i have put a t junction in it so that i can shut off air to exhaust when duno tuning.

---

very interesting.

I have block off plates installed and PAIR solenoid and hoses removed. Airbox hole is blocked with a plug.

I have felt the suction with my finger on the tip of the hose when it was still on the bike. Seemed significant but I was told otherwise.

I suppose I would need to modify the block off plates to accept a line from the crank case.

The acceleration pop would probably be increased because now you are reactivating the PAIR system. By allowing the engine pulses to suck air into he exhaust, you would start to burn the fuel byproducts and get more of the pops.

Do you have any pics of your setup?

---

i had block off plates installed but put the old caps back on and left in the reed valves, dont have photos but will take some next time i have the fairing off. deacceleration pop is stil not there as i think it creates plenty of vaccumm in the crankcase and has very little airflow out once this happens.i removed the oil filler cap and there is a significant amount of vaccumm there.
the guy that dynoed my bike was highly reccomended and does a lot of race bikes in nz told me about 2-5 hp on bigger engines but only in the last couple of thousand rpm but also stops allthat warm dirty air from going through he engine.
i gained 8 hp at after dyno tune

---

* Last updated by: andypandy on 4/16/2013 @ 8:51 AM *

---

I'm sorry. Did you just tell us you got 8hp from nothing more than a crankcase breather?

---

no that was just from dyno tune after fitting new exhaust, have not dynoed since i did breather mod but dynoe tuner had told me i could expect to gain 2-5 hp with breather mod

---

ha!! I've always been intrigued with this mod. I've gotten to the point where I'm obsessed about the appearance of the motor and everything under the fairings. The old caps prolly might have to stay in the OEM parts box for ever. I could make it a winter project to drill and solder fittings on the pretty block off plates I have now.

Reed valves are still in mine / Muzzy install instructions.

.....so on yours, there is a hose that connects across the reed valve covers and a T that comes off of that?? And the T goes to the crankcase? Where does the T hose connect to the crankcase?

---

i have a t section across the reed valve covers and a 13mm hose that goes to another tee joint beside radiator over flow bottle , it then goes to a joiner that is 13 mm on one end and 16 mm on the other this then plugs into the existing engine breather hose , i then just blanked off the airbox connection.
i put a tee joint in beside the radiator overflow so that it is easy to close off the reed valve covers outlet and still have the breather open when dyno tuning or using a self tune module.under normal running i have 1 outlet blanked off.
hope you understand all that and will post photos in. couple of days

---

Yes I understand everything except I am not sure about how that second T joint by the radiator overflow bottle functions as a shut off for the PVC system while still allowing normal engine venting....unless you have a little valve on that T that you can turn off and on like a faucet. That would be cool.

I don't understand why you would ever want to tune for performance without the PCV functioning. Once you have the PCV operating, you always leave it on, NO?

Can't wait to see pics, andy. I love the idea of using engine exhaust and parts that would otherwise be thrown away to boost performance.

---

the only reason to have a tee beside overflow bottle was for dyno or self tuning if you leave it venting through the exhaust there is a risk of oxy sensor showing a lean mix so i put t there just so it is easier to access.

---

Ah...ok. That is the same with my Dynojet Autotune equipment. I always had the PAIR blocked and later I was told that is exactly what is needed for accurate o2 sensor readings. Now I understand it is for tuning that you have the shut off valve for your PCV. However, that raises another question.

If you shut off the PCV system to tune your engine, and tune using an exhaust sensor, you are tuning for performance without PCV. Then when you are done tuning, you turn the PCV back on. After the bike has been tuned, it does not have optimum fueling to accommodate PCV? Perhaps it takes a skilled tuner to estimate the proper fuel trims for the upper rpm range where the PCV has a noticeable effect on performance.

* Last updated by: Rook on 4/18/2013 @ 5:15 AM *

---

Rook, I think the way PAIR works is to inject the air AFTER the exhaust valve.
In other words the air fuel ratio in the exhaust does not reflect the air/fuel ratio that was burning in the cylinders and therefore not what Autotune or any other measuring tool should read for tuning purposes.

Using the PAIR inlet as a source of vacuum to scavenge the crankcase is a cool idea.
I wonder if the timing of the PAIR valves opening would be be the best or worst time for suction from the crankcase?

I always assumed there was a lot of air turbulence in the crankcase because the underside of the pistons would be pumping air back and forth....

---

But after I re-read your post perhaps you meant the Postive Crankcase Ventilation (PCV) changed the fuel ratio, in which case ignore my comment.

---

Rook, I think the way PAIR works is to inject the air AFTER the exhaust valve.
In other words the air fuel ratio in the exhaust does not reflect the air/fuel ratio that was burning in the cylinders and therefore not what Autotune or any other measuring tool should read for tuning purposes.

Exactly. A sniffer should only sample gasses from combustion to determine AFR.

But after I re-read your post perhaps you meant the Postive Crankcase Ventilation (PCV) changed the fuel ratio,

PAIR or PCV would do the same thing to the emissions. The PAIR would be sucking air from the airbox. The PCV would be sucking air from the crankcase. Either way, the ultimate effect would be more oxygen in the emissions. This might be interpreted by an exhaust sensor as less CO2. It would appear to the sensor that the engine was running leaner or richer than it actually was....depending on what kind of sensor was sampling the exhaust.
...at least that's how it seems to me.

* Last updated by: Rook on 4/18/2013 @ 11:01 AM *

---

....however it seems to me there would be a lot less air entering the exhaust with the PCV. With the crankcase vent in use as PCV outlet, there would be no direct inlet for air to the crankcase. That is how the suction is created. less air in / more air out = vacuum.

I have many, many questions now.

* Last updated by: Rook on 4/18/2013 @ 11:02 AM *

---

you are absolutly right Rook once it has created vaccumm in the crankcase there should be no more air enter the exhaust. i removed the engine filler while engine is running and there was a lot of vaccumm there , how ever there may be in a slightly worn engine blowby past the rings or maybe a leaking seal of which could have an inpact on exhaust readings when tuning and i think you really need to eliminate these by blocking it off while tuning.
i have since been doing a bit of research and have read some interesting stuff ,it is a common mod among drag racers in big block v8s and the new ducati pagani has a vaccumm pump on the engine. it is suppose to create better ring sealing so manufacturers can in theory use lighter rings.
the more questions that are asked the more intersting it becomes

---

Interesting that I found a few references that the vacuum in the crankcase is used in race engines to reduce oil leaks, especially drag engines since they are pulled apart so often they avoid using gaskets.

So what we need is some dyno evidence to indicate if it really does increase power, which will be somewhat obscured data given that the A/F ratio may be affected by the process - implying you could get the same result with a tune.

PCV normally has a one-way valve to prevent blowing exhaust into the crankcase. Will the PAIR provide that - I'm guessing it would. Having one of my 3500 rpm decel pops going into the crankcase ...

---

i have left the reed valves in so is one way only so will prevent any decel pops going back into crankcase ,the other reason for doing this is to stop warm ,oil contaminated air from the going through engine combustion process , would be interesting seeing dyno results , i have just gone off what my dyno guy had said, he seems to be he prefered tuner for the majority of race bike here in nz.i will attch photos of how i have done the mod .one thing i have noticed is he bike seems to be smoother but not sure if just from breather mod or dyno tune.Your text to link here...

---

i removed the engine filler while engine is running and there was a lot of vaccumm there

You ran the engine with the oil filler cap off the crankcase and felt suction with your hand on the filler hole...interesting.

there may be in a slightly worn engine blowby past the rings or maybe a leaking seal of which could have an inpact on exhaust readings when tuning and i think you really need to eliminate these by blocking it off while tuning.

Yes, it would seem so. However, you wold be tuning for an engine without PCV and then running the engine with PCV. It may be that the improvement with PCV is only 1.5~2 hp on the top end so there is little need to tune for it. That is the case with a race air filter. The gain (maximum of 2 hp) is so slight that the fuel trims are no different for the same engine run with a stock air filter. Since converting the PAIR to a PCV system is a free mod, I see no reason to not do it even if the gain is modest. A race air filter is 80 bucks. 2hp is 2hp whether you pay for it or not.....and if it's 5, that's even better if it's free.

* Last updated by: Rook on 4/18/2013 @ 7:52 PM *

---

Thanks for pics, andy. If I may, I will provide a little narrative to recap the info we have thus far. Please correct me if I have any misconceptions so I can come back and edit this post.

PAIR reed valve covers with solenoid replaced by two short legths of 13mm hose and the upper T-joint. There is a long legth of 13mm hose that is connected to the third fitting of the upper T-joint

Long 13mm hose from upper T-joint coming out of engine compartment to left side.

Long 13mm hose to lower T-joint located above radiator overflow bottle. In the lower T-joint's fitting opposite of the long 13mm hose is a red valve(you can see peeking out behind overflow bottle cap). There is another length of 13mm hose connected to the third fitting of the lower T-joint. This 13mm hose is connected to a joiner (the black plastic fitting)that expands to 16mm on the opposite end. The 16mm end of the joiner is connected to the engine breather hose which goes directly to the crankcase.

The red valve is used to switch airflow between the PAIR system for PCV or the outside atmosphere for passive engine vent.

I do not understand how the red valve works (it just looks like a simple plug to me) but I know what it does. That is all that is important.

Excellent pictures, andy. I know how hard it is to photograph the top of the valve cover under the air box.

* Last updated by: Rook on 4/18/2013 @ 7:47 PM *

---

the wee red bit is indeed just a cap to close off tee joint i would need to pinch hose above this and remove cap when i do dyno or self tuning

i could hear suction only when i was removing the cap.
hope this clears everything up

---

i would need to pinch hose above this and remove cap when i do dyno or self tuning

OK..makes sense now. Thanks.

---

I like this mod, used a similar setup on my zx10. Why aren't there any kits available for this mod? Does anyone have any input on the smallest lightest hoses and T's that could be used? I don't like thick reinforced heater hose and copper/brass fittings..

Might as well keep things short..
T-REV ? System Ninja ZX-14R
Has anyone ever seen this before? I can't quite understand the description, but it must be some kind of electric pump to pull vacuum in the crankcase?

* Last updated by: CoolBrzBlu on 6/7/2016 @ 12:16 PM *

---