Oil breather fittings for catch tank

[edh]

That looks a lot like mine....

I don't think they are going to be all that necessary for most people - I wanted to fit mine, like Peter, to investigate my oil consumption a bit further. After a couple of thousand miles, including 200 miles at the 'ring, it hadn't collected anything.

From that I concluded that I'm not getting blow-by, which is good, and am probably losing a bit through the turbo oil seals. I do still collect a bit of oil in the inlet pipework, post turbo, so that's the most likely candidate. Interestingly the oil consumption has stabilised as well, with Silkolene 15w50 - I suspect this may have a little to do with increased oil cooling, moving oil temps on track down from 130C to 110C. (I know we're in danger of getting onto an oil thread here...). Off to Scotland today for a 600 mile round trip - I'll see how much it uses.

 

[pauly]

ORIGINAL: edh

ORIGINAL: sawood12

Where did you get that one from Ed?  Is it one that doesn't vent to atmosphere?

I bought it from a chap who was breaking a 944 turbo - a sprint car that he'd hit a tree with..[]
It doesn't vent to atmosphere - that's not a good idea as you don't want to pressurise the crankcase (leads to leaky sump gasket etc..)

Perhaps I'm missing something here but how does venting the crankcase breather to atmosphere pressurise the crankcase ?.

 

[sawood12]

I think because the crank case is usually below atmospheric pressure because the turbo is sucking air out of it, which is why we get oil sucked up into the intake system, so by venting it to atmosphere you are effectively increasing the pressure and pressurising it relative to what it was before.

 

[edh]

I think most cars use PCV - positive crankcase ventilation, using the inlet vacuum to pull out gases from the engine.

 

[Peter Empson]

Well its with some quite considerble relief that it seems almost all of my oil consumption was due to the squashed breather pipe, the same journey that emptied the dip stick last month resulted in a drop of about 1/8th this time. The back of the car is still getting covered in crud, but it's nowhere near as bad as it was.

 

[edh]

I bet that's a relief [] - when something goes wrong on my car, I always fear the worst!

If it's still kicking out smoke, I'll try not to get too close behind you at Silverstone [] (If I can keep up with the new lightweight machine [])

 

[Peter Empson]

You could say that! I think the current mess on the back is from having a rather short exhaust pipe and a colour that shows up the faintest mark (I never knew it would be so difficult to keep clean). I dread to think what it'll be like when I go for the side exit exhaust.

Thanfully I don't think it's smoky at the moment, I've never seen any trace out the back anyway, but you wont be behind me for long, I'm far too out of practice to put in any good times at the moment []. Now if I get the SC fitted (I know I'm running out of time) then I may at least be able to stay with you on the straights []

 

[edh]

Stop posting here & get back in the garage Peter - only 14 days to go []

I should have my DPW fitted this weekend, so I will be a bit quicker down hangar straight - last time I had a boost leak & was dropping to ~ 8psi at high revs - now I should be able to hold 15psi [][]

 

[Peter Empson]

ORIGINAL: edh

Stop posting here & get back in the garage Peter - only 14 days to go []

Lol! I'm stuck at work most of the time so I've only really got 2 days to do it in [], i'm going to skip going to the FoS on Sunday so that doubles my chances [] If it's still this hot then it isn't going to happen, far too warm to work in the sun.

 

[Diver944]

ORIGINAL: Peter Empson

If it's still this hot then it isn't going to happen, far too warm to work in the sun.

Happy to lend you my marquee to keep you cool in the shade [8D] Can also help with passing spanners and adding expletives when it turns out the one you need is missing

 

[Peter Empson]

Cheers Paul [] much appreciated, I may give you a shout.

Talking of the heat, not clever timing but I've just adopted a new cat and we're having to keep all the windows latched to stop her getting out till she's used to us (she's fast and clever). They recommend 3 weeks before she can go into the garden, I think I'll have lost a few stone by then...

 

[Diver944]

Your dastardly light weight schemes get more and more serious don't they []

 

[Peter Empson]

 

[Peter Empson]

I finally got around to taking some pics of my oil catch can installation.

It seems to be working well, it's a really handy location both because I was able to use pre existing holes in the chassis and also because it's dead easy to drain it from underneath the car without making a mess.

I've not done many miles since and it's already starting to fill up []

 

[944 man]

Pete, its off topic I know: but would you mind adding a few more pictures of the lamps and the area freed behind them, when you can? Thank you.

Simon

 

[944 man]

ORIGINAL: sawood12
...John at Vitesse reckons that the oil air will have no effect on the operation of his MAF unit...

I appreciate that it is his kit, but I believe that he is mistaken. Ive seen scores of Imprezas which have died as a result of oil contaminated mass airflow meters. Holed pistons and run big ends usually: all caused through running lean... Id be extremely careful.

Simon

 

[Peter Empson]

ORIGINAL: 944 man

Pete, its off topic I know: but would you mind adding a few more pictures of the lamps and the area freed behind them, when you can?  Thank you.

Simon

Hi Simon, I can't seem to find any suitable pics at the moment, but I'll make a point of taking some when my car is back from the garage (not sure when that will be, but sometime over the weekend I hope).

 

[EddySpaghetti]

Can I ask a couple of newbie questinos at this point - oil consumption is very close to my heart, but I'm not sure I understand the purpose of the breather and why it could cause increased consumption.

What does the breather hose connect - sounds like crankcase to inlet manifold (but is it before or after the AFM / Turbo)?

What is it there for? - Is the idea to stop pressure build up in the crankcase through the small blow past that will occur past the rings each compression stroke - I would have thought the compression and induction strokes might balance each other out?

Lastly, if the pipe is there to ventilate the crankcase, wouldn't it tend to suck oil into the induction system when the pipe was open, not closed (crushed). If the pipe is crushed doesn't that mean that it is basically operating as a sealed crankcase - in which case why does that increase oil consumption - is oil getting up past the rings beacuse there is a positive crankcase pressure below the pistons on the induction stroke, but not being forced back during compression?

Hope the questions make sense?! Thanks for any help - Once I understand theissue I will definitely be checking this out to see if its responsible for my high oil consumption - would prefer this to Turbo rebuild!

Cheers,

Eddy