Breather opinions please

[CornishSilver]

Having done some research there seems to be split opinions on engine breathing with twin carbs. The Yanks seem to prefer a pipe to a separate breather filter and yet this side of the water most seem to vent to the right hand carb. Not many mention just venting to atmosphere which is what I currently have. My oil filler neck is leaking so its prompted me to by a csp breather tower. I have already decided not to vent to the rocker covers and blank off the two bottom nipples, so it leaves me with the choice of the 3 options mentioned. I think that the tower has baffles that is going to deal with oil mist so I'm leaning towards just running some pipe from the top nipple and out of the bottom of the tinware. I do like the idea of the Yank approach although id be concerned of the filter getting clogged and in turn blowing a seal. I do also like the look of venting to the right hand carb but is this really necessary? As they are a pair would this not make one act differently to the other? I did read somewhere about a euro carb technician saying ideally not to vent to the carb.

So what have you done or would you do? My engine is a 1776 so no monster breather.

Thanks guys

 

[CornishSilver]

As an after thought, using all three outlets to air filters, yankee style??

 

[SiDev]

I've got a 1641 with twin Dellorto 36's, I've vented to the top of the right hand carb and haven't noticed it running any different to before it was vented. Simple to do, looks neat and is effective.

 

[Moseley]

The general consensus is that a bit of vacuum pull on the tower breather and both rocker covers is the best option. Similarly, you want to minimise the amount of oil being drawn into the carbs so ideally you'd have the 3 breather pipes fed into a catch-can system that is then plumbed into a carb or two to get some vacuum pull through it.


Sent from my iPhone using Tapatalk

 

[CornishSilver]

Thanks for the reply guy's.

Sidev, I have twin 36 dells as well, did you go exactly into the top middle of the carb or is position not important?

Mosely, pretty much what you have said is what I intended to do, however when I run it past vwheritage (as its one of their ssp engines) they said going to the rockers could cause problems although I didn't fully understand what the guy was on about. Maybe I will ask again. I was thinking 3 hoses from tower exiting on the underside would cause a vacuum the faster you went, not 100% sure of this though :?:

 

[K@rlos]

This is the set up on my 2110









Fuel block off , oil filler and rocker covers are vented to the fast fab breather box, Doesn't blow out a drop even when it's being revved to 7000rpm and no pipes going to the carbs either.

 

[sparkywig]

Rocker covers not vented, just the oil breather into the breather box and then vented into the air filters.

 

[K@rlos]

Rocker covers not vented, just the oil breather into the breather box and then vented into the air filters.

 

[CornishSilver]

First 5 replies and all different set ups :rofl: now I know for sure which to chose. Teach me to ask a question that I knew was large multiple choice with personal touches. Quality pics and engine bays chaps

 

[SiDev]

It's mounted off-centre, towards the back of the filter top, can be seen on the left in the photo.

Sent from my iPhone using Tapatalk

 

[CornishSilver]

^^ Thanks ^^

 

[holeydub]

If it helps, I ordered a gene berg breather tower and it was recommended to have as a minimum an outlet on each rocker cover and an inlet onto the right hand side carb and if you move into a bigger stroker and not using the mechanical fuel pump having the fuel pump block off as an additional outlet can be beneficial but not 100% necessary...

I had also read that the capacity of the breather should match the cc of the engine as close as possible 1776cc - 1.8ltr breather etc etc...

 

[Trikky2]

These engines are not sealed. A little suction from the inlet helps prevent/reduce oil mist emerging from behind the engine pulley.

Without this there is a likelihood that when running the heater, there will be a smell of engine fumes.

 

[CornishSilver]

These engines are not sealed. A little suction from the inlet helps prevent/reduce oil mist emerging from behind the engine pulley.

Without this there is a likelihood that when running the heater, there will be a smell of engine fumes.

I have exactly this at the minute Tricky, good to know we will be fume/smell free when I get around to fitting it

 

[*Sam*]

You could always vent the case from the fuel pump (swap to an Elec fuel pump if currently stock) that way no need to vent the rockers.



Sent from my iPhone using Tapatalk Pro