Peoples thoughts on this breather mod

dewismotorsport

http://www.j-body.org/forums/read.php?f=40&i=186733&t=186733

I've blanked my pcv off and at the minute only have a catch tank coming off the main breather so feel I need more once on track

evocarlos

shame the engines not lower you could fit a filter breather cap and save the effort of the above

dewismotorsport

I could potentially weld 90 degree pipes on so they hang over back of engine.

I've seen some of the vx220 efforts of running a filter off the filler cap but I'm not convinced 100%

dewismotorsport

Right I've done some serious Internet reading on this, plan is this:

Mod filler cap either like below but run pipe round to my catch tank

Or buy this and get a 90 degree coming off it and back to catch tank
http://www.metcomotorsports.com/proddetail.asp?prod=MBR0003-10AN

And then modify the blank with a M22x1.5 dash fitting and run pipe up to catch tank, or just drill out a old blank and weld a pipe to it and run back to catch tank

Will test both at Bedford on the 28th of feb and report back

evocarlos

found these

you could also add suction to the catch tank from the filter end this would increase the crank case ventilation

vocky

the oil filler cap mod works very well apparently, I know the guy who owns the red vx220 pictured above (y)

Dave_Gilbert

I know its slightly off topic but anyone got any ideas about the breather/vacuum pipe on the front of the rocker cover.

I need to get a pipe from there to the turbo at the back?

On the net rocker cover its on the back.

dewismotorsport

Cheers Carl, them holes in filler cap look tiny, I think I'm gonna leave the cam cover alone for now and just mod the cap and observation blank. I have read about's adding a hose pre tb but want to avoid any chance of oil vapoured air going back through engine if possible.

That's good to know Vocky thanks, I know people are only seeing these problems on track so want to give the engine the best chance before trackday.

Dave_Gilbert

I like the look of the AN fitting oil filler cap.

TFD

I think it's possible to just get an atmospheric breather (pcv between runner 2 and 3 closed):

Camcover -> Hose -> Catchcan+breather.

You only have problems with positive cranckpressure so you need an escape for the pressure.
Technicly I don't think you have to make a connection to the intake manifold or intake pipe for suction.

Any thoughts on this? Am I right or wrong?

dewismotorsport

I currently have this:

TFD

Exactly

evocarlos

dewismotorsport said:
Cheers Carl, them holes in filler cap look tiny, I think I'm gonna leave the cam cover alone for now and just mod the cap and observation blank. I have read about's adding a hose pre tb but want to avoid any chance of oil vapoured air going back through engine if possible.

That's good to know Vocky thanks, I know people are only seeing these problems on track so want to give the engine the best chance before trackday.

but thats what i meant and that's what a catch tank is for
rocker cover>catch tank>air filter 🙂

dewismotorsport

Ah I thought you meant back to pre throttle by air filter

evocarlos

i did 🙂 the catch tank removes the oil vapor from the valve cover

milo

What size is the pipe coming off the rocker cover? 13mm or 16mm?

dewismotorsport

evocarlos said:
i did 🙂 the catch tank removes the oil vapor from the valve cover

Ah right, been tested and was found to give sc a light film of oil so no good

milo said:
What size is the pipe coming off the rocker cover? 13mm or 16mm?

13mm I think, two breathers are 25mm id always meant to be bigger despite a lot of cheap tanks out there doing the same size in and out

corsaZ22se

mines been fine using the pcv in the manifold as standard sc with just a breather on the cam cover.
will put this in to a catch tank soon to keep it legal for road use.
laminova cores are free from oil in mine, no sign of oil in manifold.
the last n/a engine I built on bodies had a catch tank, cam breather > catch tank > vent filter (not inlet filters)
not sure of the date but modern cars are not allowed to vent crank case breather fumes to atmosphere where as older cars did. they just had a pipe from rocker cover running down the side of the engine.

evocarlos

dewismotorsport said:
Ah right, been tested and was found to give sc a light film of oil so no good

the way i see it is thats what you want as it keeps the rotor gap in check 🙂

dewismotorsport

Problem is road and track are two totally different animals. Road use you will never see a problem but on track where it's held almost continually at WOT it becomes a problem and end up getting blow by if not treated.

I 100% don't want oil vapour going back through system as its taking away from clean oxygen rich air so is no good for combustion.

The vx220 boys have reported problems both with the pcv open and closed so I'm trying to fix a potential future problem before I get on track (y)