4 replies to this topic

[westlin]

My son has a 1275 Cooper, the current timing chain cover has a breather fitted, but the covers mounting flange is as flat as the peak district. I've seen lots of covers without the breather. Does it need one?

Thanks in advance.

[nicklouse]

the A series engine does like to breath but not all had chain cover breathers,

[hellom8]

I orignally had an 89 MG Metro engine in my car, which had no breather on the timing cover.

The auto box and piston rings went on that engine, so I relpaced it with another MG Metro engine (same engine number pattern).

This engine has a breather pipe on the timing cover, so I have assumed it's an improvement and left it on, however I did have to shim out the rad fan as it was hitting breather canister.

[gazza82]

Most 1275s have the timing cover breather because the tappet chests are not removable covers as in the smaller capacity engines. Some had breather pipes on the rocker covers as well but after-market alloy covers do not always have one. You need something or it can blow the rear crank seal.

 

There are parts available to put a breather where the mechanical fuel pump goes rather than a plain blanking plate too.

[Ethel]

You don't really want a breather on the rocker cover. The circuit allows air in through the filler cap and draws it down with breathers that are ported to the crank case, where pressure is created from piston blow by. The chain cover is a great location as there's a sizeable port to the crank case and the chain sprocket does a good job of flinging oil away from the breather. Though a clutch cover breather alone will do just as good a job of communicating manifold vacuum - there's still only one pipe on the carb.