Engine Breathing for 948

[chesney]

I know this can be a can of worms on here but we will see.
When I got my 948 moggie it leaked from the rocker. After two gaskets, I found that the cover itself was bent so it couldn't seal. So I bought one from a Metro for the pricey sum of £5.
Since I have put this cover on it leaks oil, but not from the rocker gasket. It doesn't drip when standing so I guess it is being forced out when in use. It has a vented filler cap but I assume this is not sufficient as when I check for mayonnaise there is plenty, and sometimes there are water droplets too. Just so you know how much it uses I had a 5 litre oil can for top ups only, it is empty in 3000 miles ish..
So I have been considering tapping the rocker cover for a breather. But then I had a brainwave. I have a redundant 1100 engine in the workshop that has the tappet chest breather system. Could I use the tappet chest breather on the 950 and replace the vented cap with a solid one? It will be routed through the carb as it has the provision (currently blocked with a section of hose and a bolt).
I haven't seen any 950's with this arrangement, but I can't think why it would be wrong if it was used for late minor engines..
TIA.

[mike.perry]

The 948 should have a breaather pipe from the tappet chest, check that it is clear, a pipe from the rocker box to air filter or preferably to the carb if you have a later carb, and a vented oil filler cap.
600 miles to 1 litre is not good but not excessive

[chesney]

Ah yeah, forgot about that one
It has a later carb with the provision on it, looks like I'll have to tap a hole or find another rocker cover then.
How is best to check it is clear - I was going to prod some old guitar string up there - good move?
I wouldn't mind if it was 'using' the oil but as far as I can tell it is just falling out!

[JOWETTJAVELIN]

You must keep the breathing as it was designed, which means replacing like with like, even the oil filler cap.

[MarkyB]

Do you get blue smoke from the exhaust at any time?
If you rev the engine a bit with the oil filler cap off what happens?

[bmcecosse]

Forget the leaky oil filler cap - it releases nasty carcinogenic fumes which you then breathe - DO make sure the rocker cover breather is connected to the carb inlet pipe. And make sure the cam follower chest breather is not blocked - and if necessary extend it down slightly so it vents into the air stream below the car. Simples!

[chesney]

That concludes it then - I will have to put a rocker breather in.
MarkyB - always has the slightest hint of blue smoke but it has a problem with number 3 cylinder that I think contributes to that. Filler cap has the faintest of smoke on revs.
Has anyone here tapped a breather? Or know where I can get the piece to put in?

[mike.perry]

Remove trhe tappet chest cover and check that there is no gunge blocking the inside end of the breather pipe.

[bmcecosse]

Just straighten out your original rocker cover.

[chesney]

I'll have to find it first.. Now, where did I put that