Morris Minor Owners Club

Hello all, im currently going through my spares to make some room and I have a late engine 10ME type which I understand is of close circuit breather type, It has a unit that goes to manifold and a pipe to the crankcase, its like a jam jar top thing if you like. My questions are is the manifold different to standard earlier type and can you simply attach it all to an earlier engine or is there differences internally? I was going to pop it on mine because ive read it helps with idling?

The closed circuit crankcase system was introduced right across the A-Series engine range for Minors, Minis, Sprites, Midgets etc. There are 3 parts to it:

The control valve in the inlet manifold (PCV)
The oil separation canister on the front tappet chest cover
The hose connecting the two together

You will need both the canister/tappet cover and the inlet manifold from the later engine.

It does not affect the idle quality, unless the oil blow-by is so excessive that by sucking the fumes into the manifold, the idle suffers. It works by creating a partial vacuum in the crankcase, which helps to keep both fumes and oil inside the engine, and was introduced to help with emissions and reduce oil leaks from the rear crankshaft scroll (Minis had a 'proper' rear oil seal, so were not as prone to leaks around the flywheel).

You will see many postings about this topic and almost as many suggested solutions!

It is an excellent system - as long as the diaphragm in the valve is still in good order. Nothing different internally. Far from true that Minis are not prone to crankshaft/clutch oil leaks! But the same solution as on the Minor applies - good crankcase negative pressure is the answer......

Far from true that Minis are not prone to crankshaft/clutch oil leaks!

Roy,

What I said was they are 'not as prone', which is quite different.

Only produced the 10ME unit for 2 years.

Mainly export, but fitted to some mid '68 GPO vans.

Initially Richard it was a terrible Mini problem! Lost them a LOT of sales - and quite a few Rally success's. They then improved the design - using the 'Deva' bush (which was made in my Dept at Glacier) and of course they improved the piston ring sealing to reduce blow-by, and a better 'red rubber' lip seal running on the primary gear was introduced. But always the problem was that any crankcase pressure would blow oil past the seal - the sealed system helped a lot!