This is probably a dumb question, but here goes!

What does this do? Yes, ok, I understand it lets the crankcase breath, but why does it need to do this? what if you remove it so there is no breather? Why do some engines have a line that goes to a filter as a breather?

As standard the Busa breather goes back to the airbox, I guess you could route this to a catch tank if required?

Lots of questions, but interested to know the answers!

Ian

[Edited on 9/9/06 by iiyama]

The crank case needs to breathe for several reasons, two of which are that there will always be a certain amount of blow by which will pressurise the crank case, also the engine will genarlly pressurise due to getting hot. The breather(s) let this excess pressure out, if it weren't there the engine would just blow its oil seals and leak.

OK, that makes sense!

So how come you dont need to have a breather with a dry sump then? Breather is in the sump tank?

Pretty much. Since the pump sucks all the oil out the air then just gets sucked out into the tank. I think.

OK, thats a load off!!

Cheers!

Yep, a good dry sump is designed to purposely create a vacuum in the crankcase, so obviously you don't want a breather in situ because it then wont be a vacuum!

The reason you want the dry sump pump to pull a vacuum is because if there's no air in the crankcase, then the pistons coming up and down don't have to constantly move this air around the crankcase, so can give you a bit more power.

ah hah!

Suddenly it all becomes clearer!