13 replies to this topic

[Dunk1302]

Hi All...... I need a bit of collective wisdom:

 

I recently completed the build of a 1275 (pre-A+) engine and transplanted it into my '86 Mini Mayfair (so far so good)..... Sadly, after a few runs out, it's developed a "significant" oil leak from the crank pulley oil seal.

 

Now, stupid me forgot to fit the pulley before tightening down the timing cover (D'Oh!), so I'm not that surprised at the leak. However, I'm a bit concerned that my timing cover doesn't have a breather at all (just one on the wok at the other end), and although it's only a road-car, I'm concerned that a build-up of pressure might also be pushing the oil past that oil seal.

 

I've looked for an updated timing cover, while I'm taking the current one off to do the new seal, but can't find any with a breather, even on the bay 

 

So I'm wondering if I can improvise a breather, by drilling into the face of the cover, at the top and maybe attaching a length of pipe, to relieve any built up pressure. Is that do-able, or am I asking a stoopid question?

 

Thanks in advance

 

Dunk

[nicklouse]

They never had one on the cover. A+ metros did but it catches the fan on the Mini. Later Minis had a flattened one to allow for this.

 

there are after market covers/front plates that have them.

 

don’t worry about it. For the lack of that breather to cause a leak would actually mean your engine is in need of some serious rework.

[Dunk1302]

Thanks nick...... after the fiddle of taking the cover off with the engine in situ, I only want to do it ONCE!!! 

[Ethel]

doesn't the oil drain down via drillings in the bearing cap? Pressure build up would probably improve that, but if the leak is that significant it could be they're blocked.

 

If you were to improvise a breather it could be easier through the end plate than the timing cover.

[imack]

A series timing covers with a breather are available but relatively rare. I think they were originally fitted to Spridgets.
I bought this one from minispares over 30 years ago, you have to put a dent in the canister to clear the fan, unless you're fitting it in a clubman.

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Edited by imack, 06 April 2021 - 11:08 AM.

[Tones61]

MED alloy timing cover kit FTW

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[Cooperman]

The original 850's had a breather pipe on top of the rocker cover. From there a tube went to the air filter box. I don't know when that was discontinued. In fact, I found an early rocker only a couple of weeks ago and I'll fit it to the next modified open-breather engine I build.

It is easy to make your own and my 'S' has an alloy rocker cover with a breather pipe which I made myself. Just make sure that if you do make up a threaded hollow pipe for this the internal nut is welded to the pipe. If it came off there would possibly be a big issue.

[cal844]

I have a 1964 Hornet with an Automatic engine, it has the pipe on the rocker cover as you describe Cooperman, Iirc it was either 66 or 68 they system was updated

[Tones61]

Weld one on top cover and spray

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[Spider]

For any road car you only need 1 breather from the crankcase. If it's breathing to a point where that 1 can't cope, the issue is not lack of breathers but lack of sealing of the piston rings.

[Dunk1302]

Thanks All...... sitting here drooling at that MED kit!!!

 

Dunk

[nicklouse]

Thanks All...... sitting here drooling at that MED kit!!!

 

Dunk

Then don’t go and look at the DSNRetrosport web pages.

[MikeRotherham]

Does the standard oil filler cap with the steel mesh filter in it act as a breather?

Edited by MikeRotherham, 09 April 2021 - 07:30 AM.

[nicklouse]

Does the standard oil filler cap with the steel mesh filter in it act as a breather?

It is the air inlet for the system.