engine breathing

[steve c]

hi, i think my engine breathers are pretty standard, one on the side, ( tappet chest cover plate) and one on top of the rocker box ( pipe to air filter), should i be getting water coming out of the top pipe? its only an odd drop but its going into the air filter and has ruined it, there is no water/mayanaze in the oil filler cap, no oil in the coolant, how exactly does the breathing sytem work on this engine actualy work, i have not done a compression test yet, but i dont think i have a head gasket problem, the engine sounds good and pulls like a train, its just this spitting pipe that im worryed about, and help would be appreciated. regards steve

[MarkyB]

There will always be some water vapour coming out of the breather as water is a by product of combustion, a lot more will come out of the exhaust pipe.
However you must be getting much more than normal as it shouldn't affect the air filter so badly.
When was it last changed?

[steve c]

filter is less than three months old, about 700 miles max, its now dirty and feels damp to the touch, when ever i remove the top pipe there is always a couple of drops of water in it.

[bmcecosse]

Probably caused by short runs and engine running cool if not cold ! Do you have any indication of the temperature? Is there definitely a thermostat in the cylinder head? You could try an 84 degree stat. And when was the oil last changed ?? The breathing sucks in air from the cam follower chest breather =passes it through the block and then sucks it from the rocker cover into the filter casing. Yes - this is a crap arrangement because it plasters the paper filter with filth. Ideally a later HS2 carb could be used - it has a suction pipe on the side to take the breather pipe. But if you look at the aluminium mount for the air filter - there is room at the front to make a hole that will accept the breather hose - thus the fumes are sucked directly into the air stream as it heads into the carb - after the filter! So no more filter mess.........

t

[steve c]

BMC thanks for the advice i will certainly look into your sugestion about re routeing the pipe.

[chris_bates]

Steve,

The Minor engine needs to be able to"breathe" and as I have an after-market oil seal at the back of the engine which wraps itself around the flywheel flange, it is absolutely essential if you don't want puddles of oil leaking from the botttom of the gearbox bell-housing! I have managed to largely solve that problem by taking the breather pipe to an oil collector (a plastic container that previously contained "tinned" peaches before running it into the carb. As bmcecosse suggested, get yourself a later HS2 carb (1.5inch diam) or better yet an HS4 or even an HIF4 (1.73in diam). These carbs enable the mucky breath from the pipe to go directly into the inlet manifold and you may therefore need to make sure the system is fairly air tight otherwise it will upset the carb's weakness settings. An HS4 or HIF4 (fitted to later leyland cars eg mini and Marina/Ital) will allow more air into the engine via the carburettor and will give a small but noticeable increase in performance. You may however need the manifold as well as I believe that it is also 1/4inch bigger diameter.

I would seriously recommend having an oil trap between the exit pipe from the engine and the inlet pipe to the carb as this will enable excess oil and water vapour in the breath to condense and not go into the petrol/air part of the carb (either at the air filter or at the carb butterfly). Make sure you can empty the trap though as over time you are likely to get quite a bit of oil/water condensing out, especially if you do lots of cold engine driving.

Chris

[steve c]

Chris, thanks for the advice, i will certainly be looking into changing my top pipe arrangments.