The Definative Breather Setup Thread

[Julian Thompson]

OK.

 

Problem : Nearly all Seven's (most cars!) with a non closed loop system that I have been involved with have some kind of nasty gloopy mist seeping out of the top of the "catch tank" - regardless of how the owner plumbs this setup.

 

Further research seems to suggest that the once and for all solution is a condensing separator that has a return line out of the bottom to return the oil from the mist output back to the dry sump tower. Then, the remaining vapour is sent to a breather filter to atmosphere via a catch tank.

 

Please discuss (specifically your feeling regarding my insistance that a condenser be used)

[Beelzebub]

I run my K/Pace system fully sealed with the DS tank vent running up hill to the catch tank which has a vented cap. No gloopy stuff emerging from anywhere. I assume that any vapour emerging from the system has time to condense in the up hill hose run to the catch tank & ends up running back down to the kidney tank at the front.

 

D.

[shn7]

Awaits Peter C's input................. 😬

 

Steve.

Sussex (West) AO

Not forgetting Percy the Polar Bear

[Peter Carmichael]

Condensing means a fair chance that you keep the acidic combustion by-products mixed in with your oil. This:

a) degrades your oil

b) attacks sensitive metal components if allowed to build up

c) ... er that's about it

 

Quite how you condense just the oil and let the nasties exit stage left appears to be a problem requiring some sophistication.

 

So... three questions for you:

 

1. What's wrong with a pipe from the catch tank exiting the gloopy mist to the underside of the car? My air-tight catch tank arrangement does this which keeps the engine bay clean.

2. How clever is the condensing solution?

3. I insist that the definitive spelling of insistence differs from the one you have used. Why does the remaining vapour exit via a "breather filter"? What is the breather filter filtering?

[Julian Thompson]

Hi Peter!

 

Glad you could make it equipped with your dictionary 😬

 

Gloopy mist to the underside of the car is bad news for working on it without getting very oily. Would be nice to get rid of this problem.

 

Condensing, I guess, came into it as a way of trying to deal with the oil trapped in the mist!

 

The breather filter was meant to catch any remaining oil and allow only the vapour to escape.

 

Anyone have a practical example of the plumpbing for a non condensing system that does not give gloopy mist problems?

 

[Julian Thompson]

I guess Davesport has just told me...

 

...I've hastily replumbed my engine to this spec and am just about to go and give it a razz in the name of scientific research........ 😬

[Julian Thompson]

Seems to work.

 

The original setup on my car was rubbish, with the catch tank intercepting the return to the top of the DS tower.

 

Replumbing the catch tank to a take off in the top filler of the Pace DS tower has solved the excessive breather output issue....

 

[Beelzebub]

Julian.

 

Forgot to mention my engine's blown up more times than I can remember & the AA has revoked my cover 😬

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Only kidding

[Julian Thompson]

😬

 

I definately think that having the catch tank input going vertical up from the top of the DS tower is really helpling the issue here.

 

It will be interesting to try this in proper use on the track and see what happens.

 

I remember last year Bob Corb explained about condensing systems in a favourable light but nobody seemed very interested back then either 😬

[Jason Plato]

if your getting more than vapour out of the breather then I would be more concerned as to why the ds tank or crankcase is pressurising ? (assuming its simply not overfilled). This is usually indicative of worn rings.

 

I woulodnt be too worried about what is in the condensate - as it would have gone back into the ds tank anyway or if you had a wet sump it wouldnt have left the engine and simply returned straight to the sump.

 

Acidic combustion by products is the very reason you change your oil on a regualr basis.

 

 

here is C7 TOP

Taffia Area Rep

[oilyhands]

There is a design for a rudimentary condensing and venting system tank on my old website, been there for 10 years or so, the simplest solution is to make a layer of foam or similar around a third of the way down the catch tank, the vent pipe from the engine void should enter the tank *below* that level and the exit from the tank should be above it, that way any vapour in the venting should condense in the airspace below , any carried out of the tank will first percolate the foam and drop it's oil/water, the top exit can then be routed wherever practical, under the car or if you are masochistic, into the airbox.

 

Oily

 

Edited by - oilyhands on 24 Jun 2007 10:38:19

[Beelzebub]

Julian. I should have added to the original thread that my breather hose from the top of the Brise kidney tank to the catch tank is almost a metre in length. The catch tank sits directly in front of the heater & the hose slopes gently at approx 3 deg up from the front of the car.

 

I guess that the length of hose could be a factor in allowing vapour to condense & make its way under gravity back to the DS tank.

 

D.

[Julian Thompson]

The current car is a blackbird powered one, with a crankcase vent and a cam box vent too.

 

 

Previously, my VHPD K car also exhibited the oily mist problem even with the mocal vented catch tank fed from Caterham DS tower. That car was brand new, so certainly it wasn't worn rings.

 

Can't vouch for the 'bird - it's certainly not brand new but seems to run and go like billy stink so I'm not sure that's so worn out either.

 

My current (working) setup has just a short pipe (unlike Davesport's) but it goes literally vertically up as I tapped it in to the cap of the Pace tower! It really is a huge improvement on how Nick (Chan) had it plumbed at the start of this thread.

 

I'm going to have a look at the condensing setup on Oily's site - thanks DVA.

[Mike Molloy]

Hmmm, we had a discussion on Blackbird DS systems a while back (year or so?)

Barry Hunt had quite a different setup to mine.

Question is, where do you route the following:

1) Breather from top of DS tank (mine goes to separate catch tank, some mist escapes thru my bonnet vents when it's all hot)

2) Breather from Cam-cover (mine goes via one-way valve back into airbox. No idea what the expensive-looking valve does...)

3) Breather from crank case (Oil filler cap has been specially adapted to take a breather pipe, but mine is blocked off).

 

Mine also has a "Andy Beveridge Special" mod (bigger scavenge pump and DS tank) compared to the original "factory" setup.

 

As with all these machines various owners "evolve" them and you never quite know why various mods have been implemented.

Always interested to hear what other bird owners are up to! 😬

[elie boone]

Whats wrong with a pipe from the catch tank to the underside of the car, just ask any biker whats wrong with it.

[Mike Molloy]

"just ask any biker whats wrong with it"...

 

Err, as an ex-Moto Guzzi owner the problem is that if the catch tank overflows it pisses oil all over the rear tyre!

Not a fun experience I can tell you...

[Nifty]

I think that's what Elie was imply Mike

 

Good idea about the foam in the catch tank Dave (Oily) *thumbup*

 

Keep off the straight and narrow 😬