Crank Case Vent with Pods

[Herb]

While running just a plain hose down will work there is the chance of it pulling dirt back into the engine. That is why the hose on the stock setup is run in after the filter and the drain hose has a very small opening with a foam filter inside it.

Back in the old days, before the PVC systems, all engines had a vent tube on the crankcase. Those tubes all had a filter made of a type of steel wool in them to keep dirt out of the engine oil.

If the vent tube runs into the system before the filter it will clog the filter with oil. Some of the early PVC systems ran the vent hose into the air filter housing before the filter and every time the filter needed changing it had a large spot of oil soaked paper close to the vent tube.

[navigator]

With a long hose, it's a long way to suck dirt.
Restricting the vent with any sort of filter increases crankcase pressure.
JMO

[Herb]

With a long hose, it's a long way to suck dirt.
Restricting the vent with any sort of filter increases crankcase pressure.
JMO

That Is why the stock system goes into the airbox and the filter is at the end of the drain hose.

BTW, I have pulled the vents off of old engines and the filter in them was full of gooey dirt and the tube was coated with oily dirt. Keep in mind that the pressure does go both ways.

[FallenAngel]

With a long hose, it's a long way to suck dirt.
Restricting the vent with any sort of filter increases crankcase pressure.
JMO

The PCV system was first as an emission control system to scavenge un burned fuel gases that will build up in the crank case. I know from experence that an improperly vented system will ignite the gases in the crank case and distort pressed crank cases and rocker cove. I dont believe that is a concern with motorcycle because of the smaller crank case and the volume of oil. You may see some race cars venting the crank case through the exhaust.

I myself would not recommend just a long hose to atmosphere but instead connecting it to a vacuum source

[hillsy]

I ran an open hose on my 1500 that ran down the front frame rail, under the engine and finished near the swingarm pivot. So about 3 feet long. It was a clear hose and there was no evidence of any dirt going back up the hose or the engine spitting out oil. When I plumbed it back into the airbox it hissed and starting leaving oil in the airbox under hard riding.

Like I said earlier I think that had more to do with the smaller aperture at the airbox than anything else.

[Designer]

With a long hose, it's a long way to suck dirt. restricting the vent with any sort of filter increases crankcase pressure. JMO

That Is why the stock system goes into the airbox and the filter is at the end of the drain hose. BTW, I have pulled the vents off of old engines and the filter in them was full of gooey dirt and the tube was coated with oily dirt. Keep in mind that the pressure does go both ways.

FallenAngel mentions PVC system.

It only makes sense to have a POSITIVE Crankcase Ventialtion system over what is the "Road Draft" system. With engine vacuum working, you will always have pressure-reducing action,...besides the removal of the vapor build-up.

When the engine is running, there is never a time when a properly maintained PVC system is not doing what needs be done. At idle, ( during prolonged standstill in heavy traffic) and always.

[FallenAngel]

I ran an open hose on my 1500 that ran down the front frame rail, under the engine and finished near the swingarm pivot. So about 3 feet long. It was a clear hose and there was no evidence of any dirt going back up the hose or the engine spitting out oil. When I plumbed it back into the airbox it hissed and starting leaving oil in the airbox under hard riding.

Like I said earlier I think that had more to do with the smaller aperture at the airbox than anything else.

I would bet your plugs last lounger t.
As I mentioned Auto and truck engines need the PCV and it is an emission control application and Also Not sure if needed with the smaller motorcycle engines. So probably dont really need a Positive ventilation.
Maybe Il do the same with one of my 1400s. So I can be better informed

[Herb]

It isn't so much the need as what works best.

The open vent works but it isn't what works best. There will always be some vapor and if it is just dumped into the air it will end up coating the bike with an oily film.

The best thing is to figure out how to burn the vapor.

[hillsy]

I agree on plumbing the breather into the airbox as ultimately the best option. If it does spit out oil it then goes into the airbox drain. If you put the breather directly behind the carb then it could be problematic.

My experience with the 1500 was that it dropped oil in the airbox at times....but never did when I had the pipe under the bike. So I chose the better option.

I had a Kawasaki ZX9 street fighter which had a KLEEN air system similar to the PAIR valve on the US LC. I plumbed the crank breather straight into that system which ran the gases to the exhaust port just after the exhaust valves. Worked well on that bike.

[Designer]

It isn't so much the need as what works best.
The open vent works but it isn't what works best. There will always be some vapor and if it is just dumped into the air it will end up coating the bike with an oily film.
The best thing is to figure out how to burn the vapor.

And piping the Crankcase Vapors/etc. back through the engine is,.....The Better Option.

As you point out It is,...what Works Best,.....For all the reasons previously stated.

[hillsy]

It isn't so much the need as what works best.
The open vent works but it isn't what works best. There will always be some vapor and if it is just dumped into the air it will end up coating the bike with an oily film.
The best thing is to figure out how to burn the vapor.

And piping the Crankcase Vapors/etc. back through the engine is,.....The Better Option.

As you point out It is,...what Works Best,.....For all the reasons previously stated.

Not if feeding the pipe into the airbox makes it spew oil.

There's not a blanket right or wrong answer for every engine out there.

[Designer]

It isn't so much the need as what works best.
The open vent works but it isn't what works best. There will always be some vapor and if it is just dumped into the air it will end up coating the bike with an oily film. The best thing is to figure out how to burn the vapor.

And piping the Crankcase Vapors/etc. back through the engine is,.....The Better Option. As you point out It is,...what Works Best,.....For all the reasons previously stated.

Not if feeding the pipe into the airbox makes it spew oil. There's not a blanket right or wrong answer for every engine out there.

...Let's see now,...last I checked, this IS an Intruder Motorcycle Board,...and,...this Thread IS Titled,.."Crank Case Vent with Pods"...specifically for that same Motorcycle....and,.... what both Herb and I said (quoted above) WAS in direct reference to that said-same Motorcycle.

Soooo YES ,..what Herb said IS ..." what works best".

[navigator]

Good grief.
It's a piece of hose.

[Designer]

Good grief. It's a piece of hose.

That's what hillsy's wife says! With the same reaction too!

[hillsy]

Good grief. It's a piece of hose.

That's what hillsy's wife says! With the same reaction too!

Yeah well it is a fire hose....but I digress...

[hillsy]

It isn't so much the need as what works best.
The open vent works but it isn't what works best. There will always be some vapor and if it is just dumped into the air it will end up coating the bike with an oily film. The best thing is to figure out how to burn the vapor.

And piping the Crankcase Vapors/etc. back through the engine is,.....The Better Option. As you point out It is,...what Works Best,.....For all the reasons previously stated.

Not if feeding the pipe into the airbox makes it spew oil. There's not a blanket right or wrong answer for every engine out there.

...Let's see now,...last I checked, this IS an Intruder Motorcycle Board,...and,...this Thread IS Titled,.."Crank Case Vent with Pods"...specifically for that same Motorcycle....and,.... what both Herb and I said (quoted above) WAS in direct reference to that said-same Motorcycle.

Soooo YES ,..what Herb said IS ..." what works best".

Okay - if you plumb the hose into the pod like you have it is after the filter. No manufacturer does it that way.

If the hose pukes oil its going straight into the carb.

If you vent the breather to the atmosphere or to an airbox before the filter that wont happen.

That is all I am saying.

[navigator]

But, but, but what is the best oil mist to vent?

[hillsy]

But, but, but what is the best oil mist to vent?

Fully synthetic?

[Designer]

Okay - if you plumb the hose into the pod like you have it is after the filter. No manufacturer does it that way. If the hose pukes oil its going straight into the carb. If you vent the breather to the atmosphere or to an airbox before the filter that wont happen. That is all I am saying.

Isn't that special,...give it a rest, pal.

IT WORKS,..AND WORKS JUUUUST FINE.

Had you actually LOOKED at the arrangement I have shown you'd understand better why.

Now take you little Venting Hose and try to satisfy your wife.

[Designer]

But, but, but what is the best oil mist to vent?

Wouldn't that be as does the Stock Set Up,...back through the Engine.?