Crancase vent tube to Pair valve- for a vacuum?

OK, Suzuki 2005 GSX-R Liter

This winter project I've for the valve cover off- checked all my valve clearnaces, ~ 26K miles

I'm also removing gthe PAIR valve selenoid- to get space to get the valve cover out of the frame, etc.
I never have popping on decelleration - just to clean things up some under the air box- I'm plugging /removing it.


I have read many posts about actually venting the crankcase breather- (stock is now into the air box- no oil build up- never a problem ) to a 'T' fitting to each of the pair valve plates.

My question is:
Do i have to remove the reed valves in there to get it to create more vacuum? Or will it work well just 'T'ing off the vest hose there?

I've read about doing it during a dyno run, and gaining 2 HP!

2HP is 2HP!

 

OK, somebody here, or many know the answer to my question!

C'mon Beeb!

 

I’ll take a stab.

The reeds are there to prevent back pressure, backfiring, and such from coming back up into the intake tract, from the exhaust system. I don’t know how much back pressure you’d have in your exhaust, but, I’d like to think the blow-by would overcome it. Maybe, there actually is a vacuum in the exhaust, from a venturi effect. After you remove the pair system, you may install a fitting into the hose, with a gauge attached to the fitting, and monitor it with/without the reeds. With the reeds, if you see pressure, you know you have crankcase pressure. And, if you see vacuum, you know the exhaust is pulling, which would mean you could pull the reeds.

 

Don't know where you might have read that. There isn't really enough vacuum in the secondary air system to evacuate crankcases. However, there is an old drag racing trick that my buddy Roger and I used to do. Weld a one way valve into the exhaust collector, cut a baloney tip on it, face that away from the flow, and hook the vent up to that. Drag racers add vacuum to the crankcases all the time (electric pumps, etc.), you can learn a lot from old drag racers. We tested it on the dyno, on certain engines and exhausts, to add about 1-2 hp

Sean banned it.

 

The PAIR system sucks air from the airbox during decel while preventing exhaust gasses from entering the intake on acceleration. Connect the two PAIR valve outlets together with one tube or get a block-off kit.
The system has nothing to do with crankcase pressures. It simply provides a route for clean air to enter an over rich exhaust on decel, thus completing the fuel burn and preventing/mitigating “popping.” Naturally, the factory had to over-complicate it...

To get any benefit from a one-way crankcase breather connected to the airbox, you need a high-flow, one-way vapor connection at the crankcase that allows condensed oil drain-back, larger tubing/hose to an oil vapor condenser which, in turn, is connected to the airbox with the larger tubing/hose that also has a reed entering the airbox. Pretty sure it's race legal, at least in SuperBike.
To get real benefit from this set-up, drop an ounce of nitromethane into the oil prior to your race.
Replace the oil immediately afterwards.

 

The reed valves need to stay in.

 

Thanks- not putting a vacuum gauge on it. I might possibly use my finger over one of them while it's running, to see if vacuum though.

Thanks

I have a hose between them now.

I know what the PAIR system does, or tries to do, thanks.
There is a type of condenser on top or the crankcase now, that the vent line is attached to. I am aware how it works, and vents vertically to the air box before air goes thru the cleaner, etc. There is no build up of oil residue in there, etc. There is no reed valve up top either.
I've read about dyno indreases by putting some vacuum on the crankcase breather- that's why I was asking.
And the nitro thing? yea right.

 

After thinking about it, I feel they do, thanks.

 

Here's a short vid of a vacuum gauge on the PAIR reed plates showing vacuum, and increased vacuum with rpm.
This was done how I'm going to do it, with the solenoid deleted too.

Here's a Long, old thread on the subject, from a Kawi forum (from google search).
Here's a post mentioning repeatable gains, there are others in the thread as well.
Lot's of discussion about NOT deleting the reed valves in the valve cover either.
https://www.zx-10r.net/threads/how-to-crankcase-vent-mod.79931/page-3

 

Then, reading further, the WERA forum is mentioned in this post #121!

https://www.zx-10r.net/threads/how-to-crankcase-vent-mod.79931/page-7

 

If its a race bike, not a legal SS mod.

 

I got the valve cover back on,
hooked most things back up, started it until warm- no leaks @ the valve cover.
Here is my Crankcase breather to Pair valve bypass.





Even with the airbox off and plastics off- engine was quiet!
Sounded good.