Thread: What do I do with the Crankcase breather?

Originally Posted by Dayne

I have just fitted a new Zenith carby to my series 3 2.25ltr. With a 2nd hand adaptor plate and new 2nd hand oil bath and pipes that go along with it.

The question is this.
I have a breather pipe off the engine breather cap (Looks like a oil filler ontop of the engine), and one off the oil fillier pipe. I believe the engine breather pipe goes to the metal part of the hose that goes between the oil bath and the carby, but I have nothing to attach it to. Then the breather hose from the oil fillier goes to the intake manafold. Again nothing to attach it to.

Any ideas?

The Colonel runs so much better with the new carby started first go.

The correct setup for your S3 should have a pipe (574262) from the base of the oil filler pipe to a positive crankcase valve (542410) on a bracket next to the carburetter and thence to a pipe into the side of the Zenith adapter. There should be a short hose from the rocker box breather to a pipe welded into the fitting that goes on top of the carburetter.
This equipment is a legal requirement on your S3, although you would almost certainly get away without it.
However, you MUST have proper crankcase ventilation, and if you do not have
the above, fit the filtered caps on the top of the oil filler and on the top of the rocker cover, as on the earlier versions. The parts should be available from most Landrover suppliers. The emission control kit has special versions of the oil filler pipe (with the fitting for a hose and a sealed cap) and the carburetter to aircleaner-hose angle (with a fitting for the breather hose), but you could modify both. Avoid operating the engine either with open vents - you'll get dust in, or with no ventilation - you'll blow oil seals and sludge up the engine.

John

Anyone mind if I exhume this thread with a follow on question?

My SIII has seems to have lost its emissions system. The Crank breather pipe and the pressure relief pipe of the sealed cap oil filler goes to a brass Y piece, from which the third pipe off it dumps the oil (Quite a bit) overboard. I'm also having fun setting up the carby and general running, thinking this may be part of the issue.

Always thought it looked a bit odd and this post explains why. So I'm thinking of putting it back as it should be. My Carby air inlet from the oil bath has a spur on it for the crank case breather pipe, but it looks like its always been blocked off with a brass cap. I think Ive found the vent on the Carby mount that the positive crankcase valve (542410) sits on, but its connected to the brake servo! The brakes seem to work fine albeit with a slight 'sigh' which may be its odd connection or a split in the rubbers.

Attached a few pictures, wondering if the enlightened amount us could offer some guidance on

should i bother sorting it out or just leave it as it is, a replacement positive crankcase valve is about 50 GBP+!!
Is this the correct place on the carby to plug the Crankcase valve into?
If so where on earth should i connect the servo Vacuum hose too?

Thanks Ian IMG_2291.jpgIMG_2289.jpgIMG_2288.JPG

As far as I understand it from your description and the pictures, your existing setup is providing pressure relief but not circulation of air through the crankcase. The breather system needs to have two separate breathers, so that air can come in one and out the other. Lack of this will result in some conditions in a buildup of sludge in the engine and possibly corrosion internally. All depends on where youu live and how you drive!

You do not necessarily have to use the Landrover PCV, a talk to a knowledgeable car parts dealer (need to find one who remembers carburettors!) should find a suitable one for quite a bit less. Since the booster is using this vacuum source you can use the Y to go to both. Or better, use the spot made for the purpose on the top of the inlet manifold and drill and tap for a fitting for the brake servo.