shld there b a one way valve fitted to my breather system on my saff? its stage 3 so has the catch tank up next to the battery.reason im asking is because it still smokes on over-run! its had a full re-build and still doing it.iv dun all the usual things people have sayd it was, valve guides,stem seals, i think it has got better since i started using the mobil 1 15 50,not sure tho.been told there shld be a one way valve fitted to breathers but also been told otherwise! my brothers 3door has one fitted but doesnt have the breather system on it (catch tank).. im confused

 

NO one way valve with aftermarket, vent to atmosphere(through tanks) systems, as std they used a closed crank vent system, whereby oil fumes/pressure was ingested, good for some things not power though.
This one way was fitted into the centre of the plenum cover, the large hexagonal bit with a pipe coming off it, this was so that the boost wouldn't be lost as otherwise it would go out the same place and be lost.
tabetha

 

turbo?

 

turbos been done by vince at cr turbos,then sent back 2b checkd. had full re-build,new 0.5 oversize pistons,rings,bronze guides and ford stem seals. im very surprised nobody knows the problem (including myself) im led to believe that the 4x4`s do smoke on over-run because the ecu`s designed to spray fuel in2 pistons to cool them down on over-run.but i think my cars a bit worse than that...

 

How did you run the engine in ?, and what oil did you use ?, I've seen it loads with people being too gentle, and leads to bore glazing, it will always smoke for ever and day if this has happened, a common mistake.
What colour is the smoke, as that can make a difference.
Ecu's do not need to spray fuel into anything to cool on the overun, normally on ecu's that shut off they just then act as a compressor driven by the coasting engine, and so cool more than with fuel being present and generating heat!!
What is the co like as rich mixtures will lead to oil burning also.
tabetha

 

the engine got ran in on mineral oil for about 800 mile.took it easy for cupla hundred then started givn it a wee bit.not too much tho.the thing thats pisn me off the most is that its done it since i got the car.exact same and its still doing it.no beter no worse..