oil catch can project

[g2501]

hi everybody, recently I was wondering if this kind of mod is useful on a Vmax, but being myself not so expert about engines I would like to know what you think about it.
Premise : I tried to look around in this forum and on the web , but seems that there is only a pic of a heavy modded vmax with this oil cath can installed, and no technical info about it.

Goal :
avoid dirty oil in carbs
more breath to engine
clean combustion
easy removal of dirty oil using a drain valve from the small can.

Assumption :
If I purchase a small can ( let's say 20cl ) with 3 inlet and attach it to the bike frame in a position still to be defined I can use the first for the crankcase drain tube , the second (bigger) for the breather , similar to the stage 7 breather tube, and the third for a small k&n filter.
Using this setup , the cranckcase tube goes down in the can, below a custom filter made with steel wool, the breather tube goes just below the k&N filter , so it can suck fresh and clean air from outside, and the third will be use obiouvsly for a small air filter.

All in all seems to me a pretty easy and cheap mod.
the only things needed are :
1- a small oil catch can ( maybe even the chinese product could fit the bill)
2- new steel braided tube for breather and crankcase
3- an adapter M22x1,5 for the breather tube
4- a couple of hours of time.

what do you think about it?
I'm sure that most of you have already think about this, but since I don't see a lot of this mod on vmax I'm beginning to think that there are some hiddend downside....

also, will this mod affect in any way the aftermarket oil pressure gauge that I would like to purchase?

 

[one2dmax]

You will lose out the benefit of using the intake velocity to pull a vacuum in the crankcase which in turn aids in ring sealing. So, it's a bit counterproductive what you are suggesting. However, with turbo/supercharger or even big bore builds sometimes the can is needed due to some increased blowby that the engine can't vent or consume. On race cars you will see the vent tubes tied into the header to use the exhaust air velocity also create the vacuum in the engine crankcase.

Both the stage seven and my Muscle jet kit uses the intake velocity.

 

[g2501]

Hi Sean!
thank you very much for your detailed answer, I really appreciate that.
Maybe you don't remember me but moths ago I tried to contact you via facebook for information about your muscle jet kit. Unfortunately at that time I didn't know what kind of aftermarket exhaust I have on my bike nor if I have an "open head", so ended up staying with original air filter and an used stage 1 kit that I've found at a good price .

Just one last question about this mod.
looking at the stage 7 kit I see that there is a breather tube that goes directly into a small can.
If I dont' had see it wrong in the pictures the same can is used as a reservoir for both crankcase air tube and carb tubes.
That's the reason why I assumed that using a separate tank and a separate air filter could in some way "emulate" the behaviour of a stage 7 kit.
What is the difference?

as stated in my presentation post, please bear with me, because this is my first attempt to re-build a bike, and it is not so easy if you want to do things good.

 

[one2dmax]

It's just a way to help keep excessive oil from going directly into the front filters. It drains back down when the engine isn't running hard.

Ask any questions you want. Many have done the route you mention to help keep those fumes from going into the front carb set. Our kits ties into the bottom of the airbox PCV line so that stays more or less the same.

We do use a catch can normally when doing the flatslides

 

[johntmax]

When I changed my setup to flatslides I got a local machine shop to make me the catch tank shown.
I gets drained periodically via a threaded outlet in the base.

 

[sdt354]

When I changed my setup to flatslides I got a local machine shop to make me the catch tank shown.
I gets drained periodically via a threaded outlet in the base.
View attachment 58297

Sweet machine!

 

[MaxMidnight]

If you are running a standard air-box then apart from the 'fun' of trying new things then I doubt much (if any) benefit will be gained.

What is (or should) be vented into the air-box are crankcase gasses and whist this will contain some oil droplets there wouldn't be much oil, although some will condense a pool over time.
How much impact the blow-by gasses have on combustion I have no idea and even if they do sap a little power you can gain some comfort by helping to reduce pollution.

Taking your proposal a step forward rather than dumping the oil use an air/ oil separator which would re-cycle the oil back into the crankcase thus reduce oil consumption.

Such a device is used on the S7 kit although I was underwhelmed with the quality of the Dynojet one I used after fitting flat-slides.

I made my own which seems to work well, still vents the crankcase gasses into the carbs and sends the condensate back into the sump. I have not seen ant evidence of oil in the carbs.

Despite saying all the above I could well be wrong so why not have a go and see if you notice any benefit.
Good luck and I look forward to hearing the outcome.

 

[Supercharger]

Correct me if i take wrong. :ummm:
This seems on Gen.2 the crank vent fumes is leaded directly to the front cylinder ports. not to the airbox.
maybe do the same on Gen.1 with a butterfly valve.

 

[marsmax85]

Sweet machine!

Absolutely stunning unk:

 

[g2501]

thanks everybody,
I'm just coming back after several months (...and mods )to my oil catch can project.
So, to summarize here is what I learned ( please coorect me if I'm wrong) :

1- an oil catch can will give almost no benefits if standard air filter is used but anyway I have a Dyno 3000 ECU, a K&N single filter and a stage 1 , so my Max is not realy "standard". I will give it a try.

2- to route the crankcase tube and the "air breather " tube ( I don't know how to call it.... I'm referring th the Breather kit sold at exactrep) to a single oil can with an air filter will remove the "vaacum advantage" as stated from Sean.

so, right now I was thinking to something different.

first of all , let's divide the 2 thighs :

a oil can for the crankcase and eventually a breather filter

the breather tube will be more or less similar to the exactrep product. Maybe smaller or with a better quality tube, but the meaning wil be the same, and it will be left alone without any connection to the oil catch can.
A single tube with an air filter at the end. No more than this.

regarding the crankcase ( and this is the question to you all ) what if I remove the original rubber hoose and replace it with a new one with a PCV in the middle?
One end of the hoose goes into the crankcase ( that already have a pcv valve ,I know) and the other end goes into a oil catch can with a small air filter on top.

Will this configuration be more effective or it is just a waste of time and money?

 

[Vinmax]

What I did with my stock airbox a longggg time ago, was to remove the T fittings and turn them sideways. They no longer lead into the velocity stacks. They just dump to the sides, but still into the box.

I had noticed the oil residue down the carb stacks. I hated that and thought it was kind of bad to be getting oil directly down and into the carbs and on the slides (and into the pilot air jets). But I knew I wanted the vent in the airbox as well, so I'd have some vacuum pull from the box to relieve crankcase pressures.

I think I had to trim a bit of a tab on the T's to make them plug in sideways. I also put in blocking plugs into the holes left in the velocity stacks. Been running that way for years. Every so often when I pull carbs for maintenance, I dump out just the small bit of oil that accumulates in the box. It's never a lot though, and just holds to the front part of the airbox. Never even had enough to drip out the front vent hold in the bottom of the box.

I probably have pictures of my mod somewhere on my laptop at home.

Vinnie

 

[Redbone]

If I am understanding your setup correctly it would probably work if the small air filter was inside of the air box so it would get a vacuum pull from the carbs. The carbs pulling a vacuum on the crankcase is the biggest advantage for this setup.

thanks everybody,
I'm just coming back after several months (...and mods )to my oil catch can project.
So, to summarize here is what I learned ( please coorect me if I'm wrong) :

1- an oil catch can will give almost no benefits if standard air filter is used but anyway I have a Dyno 3000 ECU, a K&N single filter and a stage 1 , so my Max is not realy "standard". I will give it a try.

2- to route the crankcase tube and the "air breather " tube ( I don't know how to call it.... I'm referring th the Breather kit sold at exactrep) to a single oil can with an air filter will remove the "vaacum advantage" as stated from Sean.

so, right now I was thinking to something different.

first of all , let's divide the 2 thighs :

a oil can for the crankcase and eventually a breather filter

the breather tube will be more or less similar to the exactrep product. Maybe smaller or with a better quality tube, but the meaning wil be the same, and it will be left alone without any connection to the oil catch can.
A single tube with an air filter at the end. No more than this.

regarding the crankcase ( and this is the question to you all ) what if I remove the original rubber hoose and replace it with a new one with a PCV in the middle?
One end of the hoose goes into the crankcase ( that already have a pcv valve ,I know) and the other end goes into a oil catch can with a small air filter on top.

Will this configuration be more effective or it is just a waste of time and money?

 

[g2501]

i'm resuming this old thread for just a couple of considerations from you instead of opening a new one. I'm going to follow Redbone's suggestion and re-route the crankcase hose to a small K&N filter that I will install inside the airbox.
Removing the extra parts inside the airbox will give me plenty of space to put a small filter in there.
also I changed the airbox filter to something very similar to the Sean's stage 1 mod, so now I got a lot more of air coming in.
in this way I will avoid junk and oil to be sucked inside the carbs, and will maintain a good amount of vacuum.I have just one last doubt regarding the PCV valve.
Some months ago I purchased an universal PCV Valve in alluminium .

specs are :
Valve Opening (Cracking) Pressure: 1.5psi
WOrking pressure interval: 1.5psi to 65psi
MAX Backpressure : 72psi
Is it useful to install this small "extra" PCV valve on the hose few inches below ? or it will be dangerous ?