67panel said:
i mean in the filler ,have a look at how one is made.if your engine(stock) is putting oil out of either of the breather pipes then something is wrong.defo my last comment cos dont want to upset anyone cos loooooooove this forum 8)
Oil vapor is an unfortunate and undeniable fact in internal combustion engines.
In theory a perfect engine would leak no combustion gases into the crankcase, which would be great because the engine oil would not go black and would not be polluted by combustion by-products or diluted by fuel. Modern engines are better than those of forty years ago but even the best ones still turn the oil black after a while. I dont know if it will ever be possible to mass produce engines with a perfect seal but its not been done yet.
The nature of an engine requires parts that rotate and reciprocate rather quickly, whilst simultaneously requiring lubrication. Its not just the crankshaft rotating in the oil. On dry sump engines the lubricating oil spillage from the bearing surfaces still gets thrown around the case at high speed causing atomisation.
Without a breather system, the combustion seepage will cause positive pressure in the crankcase which in turn would force oil out of any weak points such as oil seals etc.
Breather design tries to trap as much of the oil vapor as possible, by using filters and/or baffles, to both keep the engine running clean and to reduce oil consumption but, like piston rings, they cannot be perfect and catch all the vapors. Its a human trait to look for perfection but in the real world perfection is a theoretical dream, its not real. Hence the fact that engines, including modern ones, have a breather connection to the inlet, so the remaining vapors are burnt in the engines combustion process.
Oil vapors are a significant pollutant and it has been a legal requirement, already for many years, that engines do not have crankcase breathers open to the atmosphere.
Additionally, on the VW aircooled engine the breather system is specifically designed to create a very small amount of negative pressure in the crankcase. This is because its an old engine design that has no oil seal on the crankcase where the crankshaft emerges by the fan pulley. Without the small amount of suction from the breather, oil seepage and suspended oil vapor will emerge from this area and spread over the engine over time.
If oil vapors are allowed to build up in the engine compartment it causes problems. This is why, when you examine old cars from say the 1950's or earlier, with breathers to atmosphere, the breather pipes went down to the bottom of the engine, to disperse the fumes under the vehicle rather than over the engine.
If oil vapors are allowed in the engine compartment, over time, normally the first component to suffer is the fan belt, which starts to slip and wear rapidly plus the rubber compounds of the belt deteriorate making it soft and stretchy. On water cooled cars the next thing to suffer is the rubber coolant hoses. The next components to suffer are the electrics, both in terms of damaging insulation, causing tracking on th HT system due to dirt buildup and fouling contact surfaces, like the exposed commutator and carbon brushes in the dynamo for instance.
In the case of rear mounted engines the vapors will get drawn in by the cooling fan. The oil itself wont do much harm in the cooling system initially but over time dust will stick to the oil and a gradual build up will start to affect the efficiency of both the cooling fins and the flow of the air on the fan blades themselves but, most importantly on VW aircooled engines, this buildup will clog the narrow air channels in the oil cooler before anything else.
Due to the way the VW aircooled heating system works one can always tell if the breather is not working correctly since opening the heater flaps will always give a slightly oily smell.
Those unfamiliar with how these vehicles performed originally (and should still today) might not notice or assume its normal.
I would like to emphasize it was not acceptable to arrive at ones destination smelling slightly of engines back in the 1970's any more than it is today. We used our cars to go to work, we wore suits and we worked in offices :lol:
Anybody in doubt about these facts should take their vehicle for a brisk drive to get the engine hot and then, with it running, try breathing in through the breather hose.
:lol: (no - I am joking - dont do it - it would be bad for your health) :lol:
