Breather hose question

[poohbah]

Folks, have a query about the breather hose from camcover to air-filters.

My 81 GTV has been upgraded to twin Webers, fitted with K&N air filters. The rear backing plate has been modified bu adding a nozzle to accept the breather hose from the camcover as shown in first pic. Second pic shows whole breather hose arrangement.

Thing is, the inlet hole sits flush with the rubber rim of the filter (ie it would mostly be blocked by the filter rim). Seems to me that is pretty pointless, and I imagine having it flowing directly into the inner side of the carb intake would be worse. Regardless, the base plate on the inside of the filter is pretty oil, and it does seem to lead to some oil fouling of plugs in rear two cylinders.

I am about to give the filters a good clean (as they are filthy), but is there a better solution for the breather hose set up? I've seen reference to other people simply attaching the hose to a ventilated bottle or oil can to collect the vented oil - is that worthwhile? Or will redirecting the oily airstream away from carbs have some other negative impact?

Open to suggestions, bearing in mind I'm no fabricator.

[Fetta GTV]

An oil breather  catch can would be a better solution.
Can get them fairly easily from auto stores.
They have a little filter on top.
Better tham feeding into just the rear carb.
Or go back to Standard airbox with cold air pickup.

[bazzbazz]

As per the setup shown in photo I cannot see how a "Catch Can" setup would cause problems.

[poohbah]

Cheers guys, I found this example on alfabb. Even I should be able to manage something this simple!

I assume I should block off the nozzle on the carb backing plate?

[bonno]

Hi Poohbah
Another option is to fit air breather filter directly to the outlet pipe on cam cover as per attached photo. Also have included a link to a suitable unit (just check size).
http://www.supercheapauto.com.au/Product/SAAS-MINI-AIR-BREATHER-20MM-NECK-SF-MAB20/SPO2459459.
cheers
bonno

[poohbah]

Thanks Bonno - with that set up, where does the vented oil go?

Also - this may be a dumb question - but I had a quick look at the catch cans from supercheap etc online, and they have an inlet and an outlet. Where would a hose on the outlet nozzle go to? The bottle in the pic I copied from alfa BB looks like inlet-only to me.

[bazzbazz]

Outlet hose would normally go back to the carb. the idea of the catch can is to catch the oil, the fumes still go back to the carb.

[poohbah]

Ahhh, makes sense. Thanks Bazz.

[bonno]

Poohbah
Find link to a catch can and filter combination available on e-bay. The catch can and air breather combination provides the necessary system to capture crankcase bypass gases oil/fuel mixture produced by the engine. There are many to choose from and it's just a matter of how much you can stretch the budget.   https://www.ebay.com.au/itm/Universal-Aluminium-0-5L-Oil-Catch-Can-Breather-Tank-AN6-6-AN-Filter-Black/272946173938?hash=item3f8cdc17f2:g:U94AAOSwIJlaEtaL
PS : I suspect the outlet connection on catch can could be routed back to the air filter connection, providing only dry air in a closed loop system. 

[bazzbazz]

I like this style just for the excellent mounting bracket, more expensive but also more compact.

https://www.ebay.com.au/itm/Baffled-Universal-Oil-Catch-Can-Reservoir-blue-Tank-new/162757139099?_trkparms=aid%3D222007%26algo%3DSIM.MBE%26ao%3D2%26asc%3D20140106155344%26meid%3D6e77399d504e47ef80e933897ec53aa6%26pid%3D100005%26rk%3D12%26rkt%3D12%26sd%3D123154518602%26itm%3D162757139099&_trksid=p2047675.c100005.m1851

[poohbah]

Cheers fellas. I bought one from supercheap (Calibre) but then got dragged off to other commitments. Only had time to do a trial fit but I'm not happy with the bracket provided. Will knock up a new one, and also need to buy some new hose.

[poohbah]

Ok, this is how I've ended up. As I said, I wasn't happy with the provided mounting bracket, or with the hose feedpoint going back into No2 air filter, so I made a new bracket for the can, capped the old feedpoint (which was really narrow and was effectively blocked by the inner rim of the filter), and made a new mount to feed the hose back to No1 filter.

I'm no fabricator so it's still not quite as neat as I would like, and I will probably go back and narrow the hose mount to reduce the amount of metal covering the top of the filter. I am wondering whether there may not be enough holes in the plate which could restrict airflow, though given the amount of muck that came out of the filter when I cleaned it, it should be breathing a hell of a lot better than it was anyway.

I'll give it a go for a few days and see how she goes (after weather here breaks - soon hopefully), but if any of you see an obvious problem with the way I've rigged it, let me know. Just made it up as i went along - no real science, so I won't be offended if you point out I've done something stupid.

(first two pics show "before", 3 and 4 show "after')

[poohbah]

Well I'm happy to report it does seem to have improved things. Exhaust note actually sounds a little smoother and even seems to be less "steamy" out the back when its cold.

[GTVeloce]

Why does it have a breather if you then vent the gases back to the inlet? I would have thought perhaps the inlet takes oily fumes into the catch can where they separate with the fumes heading out the vent and the liquid oil going back into the sump? With a TS engine it has an oil/vapour separator that does exactly that.

In the pic you can see the separator and the feed. Underneath is a small tube that takes the oil back to the crankcase and a hose out the side takes the fumes into the intake system concertina hose.

[bazzbazz]

Your assumptions are quite correct for these engines and how they operate in this instance, however, you're forgetting, it's a UNIVERSAL catch can that is designed to fit a multitude of different engines and applications.

In this instance the breather and its cute little cone filter are not required.