Engine breathing

[rjt1951]

Hi, Any advise please. I have a 1970 Minor with 1098 engine. It has a cylinder fitted to the front tappet cover which I have just removed to clean and fit new gasket. A rubber hose then goes to the air filter casing but having read various posts and I am not sure this is correct? The rocker cover is not vented and has the late plastic filler cap. There is a port on the carb and this has been taped up and caped with what looks like a dust cap. Should I be connecting other end of hose to this rather than the air filter housing? Having said this the bore of the port on the carb is a lot smaller than on the breather canister so I am an unsure of what to do for the best. There is no pluged hole in the manifold to indicate it once had that breather valve ( forgotten correct name) have looked at loads of engine pictures on line and everyone seems to have a different configuration. Have been getting a few oil drips of late and wondered if it could be a reason?
Any help much appreciated.
PS. have owned car for 7 years following a garage restoration and it is still doing well.

[Monty-4]

As I understand it your current configuration will vent any build-up of positive crankcase pressure from the tappet cover to the air filter housing - the normal setup for earlier Minors (although from the rocker cover I think). Connecting your breather to the carb instead will create a small negative pressure (suck) and help reduce oil drips out of the back of the engine a little more. This is assuming the carb connection you mention is in fact for engine breathing, and not something else! Bridging the difference in pipe bores could be done with a hose reducer, perhaps a fancy brass one.

The only disadvantages I can imagine from your current setup if your oil consumption is reasonable is the air filter may get dirtier quicker and your car may have higher emissions.

[philthehill]

The breathing system you describe is correct for your car in that the front cam follower access plate with breather canister Pt No: 12A1212 feeds direct to the air cleaner.
The correct carb fitted to your minor is AUD13 and the type is identified by a small plate normally attached under one of the float chamber screws.
Some later 1098cc engines had a PCV valve Pt No: 13H5191 fitted which connected to the inlet manifold by a 5/8" UNF union. The top inlet of the PCV valve is connected to the front cam follower access plate with breather canister outlet.
The rocker cover is correct in that it has no breather pipe.
The oil drip is I suspect from either the rear sump seal or working its way past the rear crankshaft scroll.

[mowogg]

There is a pipe made which connects the canister to the carbon. The diameter reduces as required.

If you look on ebay you can find them for around 5 pounds although I imagine you can get them elsewhere too

[rjt1951]

Thank you one and all for your instant replies. Me thinks maybe I should leave it as set up. Oil loss is small it's just that it never used to drip at all. Found the breather canister contained a little mayo at the bottom. There was none however in the rocker cover so not too worried. New air filter fitted so will keep an eye and see if it gets dirty quickly, the old one did not seem too bad. It's a bit fresh in the garage to do any more today.

[rjt1951]

Forgot to report I have connected the breather pipe from the canister to the side of the carb and it seems to have stopped the slight oil drip totaly. Car seems happy, have just driven to Devon and back so will leave as set up.
Thanks for all your advise.