Just replaced the valve stem seals (Docs top quality Viton ones) on my Mk 2 S. Just did the old rope in the cylinder trick as did not have time to remove inlet manifold, exhaust..and driveshaft as described in the Gregory's manual.
(Do you really have to do that to remove the head on a Cooper S?)

Anyway, took it for a spin and still smoke on over-run. Compression good and even over the cylinders.

When preparing to replace the seals, noticed one plug oily and when putting rope in cylinder, found that matching cylinder oily as well. Looks like the valve stem has worn and so am I right in assuming this worn area on the shaft could allow oil through?

And if so, need a new unworn valve to fix this smoking I imagine....



Thanks for any help on this!

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Cooper S Mk2
Cooper S Mk1
ex Cooper S Mk2, various Morris 1100s, 1300s, 1500s, Leyland Sherpa!

Thats a shame after all the effort to replace the seals too! Sure can let oil down, particularly on the overrun as cylinder pressure is up to -20 psi. So it will just suck oil down the guides.

Its obvious with the head off, you can rock the valves in the stems.

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SooperDooperMiniCooperExpertEngineering

All garage work involves equal measures of enthusiasm, ingenuity and a fair degree of irresponsibility.

Thanks Mick!

Fist time for me - a good 5 hours and sore neck!

I was trying this quick fix as have been invited to show my car at Muscle Car Masters with Mini Club NSW in September, and going O/S for a couple of weeks so short of time.

Apparently we will be doing a parade lap or 2 with the Mustangs!

Looks like I will do a proper job after then. Do I really need to remove one drive shaft to remove the exhaust?

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Cooper S Mk2
Cooper S Mk1
ex Cooper S Mk2, various Morris 1100s, 1300s, 1500s, Leyland Sherpa!

No, you shouldn't.

When I'm just removing the head, I don't really want to wrestle with the exhaust if I can.

I use two nuts on the manifold studs to lock together, and then unscrew the studs all together. Then te head will come off and go back on without having to pull the exhaust apart which can sometimes be a pain.

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SooperDooperMiniCooperExpertEngineering

All garage work involves equal measures of enthusiasm, ingenuity and a fair degree of irresponsibility.

It may not be the valves...
It could be sucking oil up past the rings, good compression results or not.

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

Thanks Mick and Doc,

Will do the valves and guides when I can and in the meantime, save up to get the rings etc done if necessary.....

Would have to be done one day anyway!

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Cooper S Mk2
Cooper S Mk1
ex Cooper S Mk2, various Morris 1100s, 1300s, 1500s, Leyland Sherpa!