Definitive Small Block Engine Breather Arrangement ???

[Clancy]

Nice job Waxi.
Yeah, I wanted to get right angles too and couldn't come up with anything.

[Psychopasta]

Hi, I've joined Team Curtis and have one of his little plastic bottle thingies to replace the breather box. My question is how high should I have it, relative to the output vents on the cylinder head.

My preferred location is right up on the steering headstock where it can be concealed by the tank. That puts it high relative to the vent output, so oil could contense out of the vapor and flow back to the cylinder head. Is this desirable or undesirable? It means that more oil returns to the head and less via the sump, but I'm not sure if that's good, bad or indifferent.

Mounting the bottle lower than the head vents means no oil will ever return directly to the heads and will all go via the sump. Any preferences? Am I just worrying for nothing?

- Pasta

[Chuck in Indiana]

Hi, I've joined Team Curtis and have one of his little plastic bottle thingies to replace the breather box. My question is how high should I have it, relative to the output vents on the cylinder head.

My preferred location is right up on the steering headstock where it can be concealed by the tank. That puts it high relative to the vent output, so oil could contense out of the vapor and flow back to the cylinder head. Is this desirable or undesirable? It means that more oil returns to the head and less via the sump, but I'm not sure if that's good, bad or indifferent.

Mounting the bottle lower than the head vents means no oil will ever return directly to the heads and will all go via the sump. Any preferences? Am I just worrying for nothing?

- Pasta

Putting it up where you are talking is best. Much of the way Guzzi lubes the valve train on the small blocks (except the 4Vs)  is there are fangs on the valve covers where oil condenses and drops off. There is a *lot* of oil in the system because of the pumping action of the split crankcase. I don't understand all I know about that,  but I'd take it into consideration..

[Psychopasta]

Thanks Chuck! So you're going for the 'as high as possible' option, yes?

- Pasta

[Chuck in Indiana]

Thanks Chuck! So you're going for the 'as high as possible' option, yes?

- Pasta

Absolutely.

[Psychopasta]

Thanks! 

- Pasta

[TimmyTheHog]

Why making this so complicated? AFAIK you only need to do it like Clancy did. Left #20 goes to catch can and from there another pipe back to the same plug where #20 was before - airbox. Done.
This way you have an extra "filter" for junk and in case that it gets full you still have factory blow-by design after.

Or what?

Also, does anybody know how much does gearbox actually "breathe" over the breather? If I connect it to catch can together with valve breathers using Y joint can something get wrong? Asking because of this confusion about how much oil should be in it. I already had a oil mess coming from the gearbox breather at high revs...

Well, bumping this thread once more and simply try to clarify as too many words confuses the crap out of me LOL...

My is a 2015 V7 Stone and it is also building up some light amount of oil in my air box...most of the time I just go in and wipe it up but it gets a bit annoying after a while.

From what I read is because the way how oil lubricated the small block top end and location of the breather tube, some oil may trace back thru the breather hose back to the air box.

Now, looking at the my parts diagram which is quite similar to Waxi's (no idea why the difference), as long as I connect a catch tube between the original breather pipe (20) to its original nipple,  this will allow me to accumulate the oil while allowing the air breath back to the air box.

Is this the idea and shouldn't change the system that dramatically?

Sorry for the noob question, but for whatever reason it is just not clicking with me.

[Mayor_of_BBQ]

Well, bumping this thread once more and simply try to clarify as too many words confuses the crap out of me LOL...

My is a 2015 V7 Stone and it is also building up some light amount of oil in my air box...most of the time I just go in and wipe it up but it gets a bit annoying after a while.

From what I read is because the way how oil lubricated the small block top end and location of the breather tube, some oil may trace back thru the breather hose back to the air box.

Now, looking at the my parts diagram which is quite similar to Waxi's (no idea why the difference), as long as I connect a catch tube between the original breather pipe (20) to its original nipple,  this will allow me to accumulate the oil while allowing the air breath back to the air box.

Is this the idea and shouldn't change the system that dramatically?

Sorry for the noob question, but for whatever reason it is just not clicking with me.

you are on the right track, if the catch can is easier to access than the airbox, no reason it shouldn't work just fine.  Depending on your house routing, you still may end up with a tiny amount in the airbox but should be much less.

[waxi]

you are on the right track, if the catch can is easier to access than the airbox, no reason it shouldn't work just fine.  Depending on your house routing, you still may end up with a tiny amount in the airbox but should be much less.

+1

[TimmyTheHog]

you are on the right track, if the catch can is easier to access than the airbox, no reason it shouldn't work just fine.  Depending on your house routing, you still may end up with a tiny amount in the airbox but should be much less.

I see...

so as long as my catch can is as high as applicable and/or higher than my breather pipe, I should have a lot less oil back to the box....correct?

I read somewhere here that filter is a good idea as air flow both direction. What if I don't have a filter?

I was thinking making something out of a small syringe tube with couple nipples sticking out of it for lines...

[Psychopasta]

Hey Timmy,

Your drawing is very similar to the thing that Curtis can sell you for under $20.

- Pasta