hi.
the crankcase breather on my engine (1100cc) is at the front, on the passenger side (rhd) and needs a hose attached to it?
the carbi has a brass outlet on the rearward side and I wonder if the two are meant to be linked together? in some way, noting
that they both have different diameters for the hose attachments!
Peter

Pete,
Of the two panels on the LH side of the block which has a vent, it should also have a tube running straight 'down' and mounted to the block nearer the bottom of the block. Perhaps this tube is missing on yours. A quick look at other motors might help you, as long as they are not 1275cc motors.
Ray W

Later models sometimes have a tappet cover plate with a breather canister approx 40mm diameter and 100mm long with a connection tube at the top end.
Mine has a special hose from that onto the brass inlet on the carb.

The special hose is available from specialist suppliers and it has a different diameter at each end.
I used this one:-
https://www.ebay.co.uk/itm/Classic-Mini-Breather-To-Carburettor-Breather-Hose-12A1735-5-16-1-2-carb/173212795350?hash=item28544981d6:g:ZGMAAOSwsFpWTKPR:rk:1:pf:0

Phil

Here are pictures of two different set ups, both of which get to the same end result.

John F. Quilter
Eugene, Oregon USA

hi,
thank you all for your replys.
I have also been advised that the hose from the crankcase breather also goes to the air cleaner via the small pipe on the underside of the base unit.
they are both the same diameter, so in my case that seems logical, but others say connect it to the brass pipe on the other side of the carbi?
if that is the correct connection, what is the small vent pipe for on the underside of the air cleaner base unit?

Peter

A lot of cars had a pipe from the rocker cover onto the backplate of the air filter, if you have the canister type connected to the front tappet cover then you dont need the rocker cover one, just leave the connection on the filter backplate as it is.

What you do need is a breather type oil filler cap, this is where the engine draws its air into the system, it is then sucked out along with fumes into the brass spigot on the carb.
If you remove the oil filler cap with the engine running you should be able to feel the suction if you put your palm over the oil filler.

I did the changeover to this type of breather system, and it dramatically decreased the amount of oil being lost through the rear crank scroll seal because of increased negative pressure in the crankcase.

Phil

very interesting reply Phil, thank you.
just checked my cap, and its a breather type....phew

Peter



Edited 4 time(s). Last edit at 2019-02-04 07:40 PM by tappetTwo.

Peter, To create a true positive crankcase breathing arrangement you need to have the Smiths PVC valve and connect that to the inlet manifold via a pipe nipple of some sort. This ties the crankcase breathing into a area of relatively continuous vacuum. Connecting the oil separator canister to just the carb side of the air filter back plate is not connecting it to an area of continuous vacuum, that area is almost at atmospheric pressure only being impacted by the filter element. See the photos in my earlier post. Phil Proctor is correct, you do also need a vented valve cover cap which has only a small orfice to allow a metered amount of air through a small gauze filter, into the crankcase.. The system I have described was standard fitment on BMC, Triumph, and other British cars from about 1965 onward to comply with US emissions laws.

John F. Quilter
Eugene, Oregon USA