crankcase ventilation hose

[chirrin]

i have a question im removin everything that my bike dont need, besides my state doesnt require emission, can i remove the crankcase hose all the way to the carb air box, tap the hole of the carb air box and just put a air filter on the crankcase hose? like old cars u know when they put a filter in the valve cover when they take off all the extra houses for performance.( i alredy took off the emission canister and houses)

[clubhousemotorsports]

This is a common question and i am sure you will get a few different answers. i will give you my .02$

removing the crankcase breather is not a good idea because....
1. hp loss
      this is debatable on many levels but the readers digest version is that the pressure returned back to the cases (like a 2 stroke exhaust) helps the pistons on the up stroke. there is a reed valve on street bikes that may restrict this. You do not see race bikes (top level) without this system installed, racers will not throw away 1/4 hp.

2. oil vapor will come out of the filter and where is it going to go?


Some people put them on because they don't care if they lose 1/4 hp (or more) to have the bike look a certain way. I say if it will still be safe why not, as long as you are aware of the down sides.

[chirrin]

i like that answer yea i wont trow out a qt of horse power it doesnt boder me the way it looks just the hose thats going to the air box is to big and bother when i take the tank down would be a proble if i put a smaller hose
?

[Capo]

Ideally, the diameter of the hose should be as large as possible, on the std set up with the reed valve on the engine, the larger diameter reduces the velocity in the hose, this helps to reduce any entrainment of oil in the 'gas' stream.
The corse set up locates the reed valve at the airbox, this effectivly increases the volume of the crankcase and contributes to an increase in power. Obviously larger diameter hoses will increase this volume further.

[chirrin]

nice! imo gonna put 6 inches pvc tube jajajaj just kiddin thanks a lot