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Discussion Starter #1
So theres two way's i've seen the kleen air mod done, one is simply with the block off plates, remove and cap off airbox and such.

The other way is to vent the crank case instead of into the intake attaching that line to the kleen system and venting the crank case through the exhaust system.

should first say i dont have a real understanding of how the valve system works through the kleen system (new to bikes) but my first thought was i wonder if that would cause things to get gummed up in there over time. On the other hand running that shit through the carb probably isnt any better.

Which way do you guys think is the better way to do it?
 

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well if you think about it its going to go out your exhaust anyways, might as well bypass running the junk thru your motor right? ive done this mod (crankcase vent to kleen reeds) and felt a noticeable difference... maybe 2hp or so.
 

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Discussion Starter #3 (Edited)
lol 2 hp eh? i doubt it, probably in your head, but i guess it does leave a tiny bit more air available for your engine...kinda

mainly wondering if theres any issue with venting into the kleen system.
 

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i belive someone explained it as drawing a vaccum into your crankcase whitch in turn helps seal the rings tighter against the cylinder walls for more compression and less blow by... could be horse shit but either way the butt dyno said something was there haha. and its cleaner for the engine also!
 

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Discussion Starter #5
interesting idea, but there would be more vacuum inside the engine, then into the exhaust (i think). regardless it does keep it out of the engine, wondering how often you might need to pull the covers for the kleen system and hit it with carb cleaner, thats not a big deal i guess tho.
 

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the inside of your engine will have pressure...combustion pressure leaks past the rings and in to the crank case...but the pistons moving up and down is an even exchange...and the pressure is applied everywhere, so gains are iffy.

the exhaust gases rushing past the openign creates a siphon/vacuum.

block off plates are nice and clean, and not that pricey. I've seen others simply tie the two tubes together after taking the valve out.
 

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Discussion Starter #7
so are you trying to say that venting the pressure to the exhaust could actually cause an imbalance in the bottom of the motor?

i actually have the block off plates but not installed, debating wether its better to use the plates or vent the crank case in there so not so much crap going through my carb
 

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depends on which way the reeds are facing and if theres enough vacuum to create a draw.

the best way to lower blow-by is either to create a case vacuum, or tighten the 2nd ring gap a thousandth or 2.
the Kleen air system injects intake air into the exhaust ports to dilute the exhaust concentrations a bit.. like a backwards EGR on a car.

the valves are one-way, and if there WAS a vacuum present in the Ex port, it would certainly draw in the reed valve chambers and create suction.. all be it minimalistic. VERY small amounts. thats IF.. i doubt honestly there would be a vac there.. might be a tiny bit from the exhaust pulse repercussion and the scavenging effect that will have, but not enough to seal 8 rings.

i made my own blockoffs out of CF.. i also made a set of aluminum (6061 T6511) but eh.. i like the CF better. no benefit other than looks. you can see em in my bike build thread in the 7-R section.

the kleen air thing is hit-and-miss.. kinda like doing a BOV on a 4th gen jetta or GTi without recirculating the vent air back to the airbox.. some cars throw codes from map pressure differentials, some don't throw any codes at all.
hit and miss.

some bikes gain a tiny ass bit of power and get better and smoother acceleration, some pop on decel and carry on, some it doesn't do shit to.

if it's free, its worth a shot.. don't trash your KA shit til you know it works well. tht way if it doesn't you can at least revert back to stock.

as far as venting case pressure to the exhaust.. thats IF you can N/A motors love backpressure.. therefore, that pressure would end up in the case.

i'm a huge fan of low case pressures. remember, the pistons are acting like a parachute on their drop to BDC. luckily, the pressure they're creating is offset slightly by the cylinders beside it on their way to TDC.
this is why we window blocks on race motors. helps with that balancing act and lets the air flow easier.
 

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The point of crank case venting is to let that blow by pressure out...if the case was sealed tight, oil would be getting squirted up into the cylinders past the rings, and various covers and seals would likely start leaking.

There is little if any goo going through the carbs leaving the venting as it is....until your motor gets really really worn anyway....so don't let that worry you.

Crank case vacuum systems are inplace on monster hp engines....but only because they make obscene pressure in the cylinders, so the blow by is huge....and added vacuum is the only way to evacuate it.

There are HP looses inside the case from moving that air around, and I suppose if that air were less dense it could add some power...but I doubt its measurable.
 

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Discussion Starter #10
hendrix its actually exactly like a smog pump on a car, and equally stupid, not to mention im getting rid of cats anyways so no real point.

As far as not much gunk going past the carb, maybe thats true? my experience is all with cars and i know with my camaro the intake runners were caked with black shit from the pcv venting. serious mileage difference but it'd still be there on a bike.

Can someone just answer wether there is any negative side to venting the crank case into the reed valves? guaranteed not having it vent into the engine means that much less often you'll have to clean gunk out of your carb.
 

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well just cleaned my carbs/kleen reeds and the reeds were slightly brownish, and the spacer dowels under the valve covers that the reeds flow thru had a small amount of fine black soot. nothing a shot of cleaner couldnt handle... the carbs were spotless tho, you could eat out of them if you liked the taste of gas haha. this is after 10,000kms of the vent mod, and ive never had a hitch with it yet!
 

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Discussion Starter #12
awesome, i'll vent through the reed's then, and just give them a clean every time its due for a major service.
 
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