just swapped my 93 magna for an ef xr6 manual with recently rebuilt engine, less than 10000km ago, engine was built for turbo application, was built all new internals, crow cam(unsure on spec) but suited for turbo, now when it was first built it was smokey, so it was pulled out thinking they had cracked a ring or 2 on assembly, but they hadn't, it was then reassmbled with another set of new rings and it is still smokey. its very fuely i think due to the cam, but it blows s**t of oil smoke on decel, not at idle or when first started, so i think that rules out valve stem seals, any ideas on what to do, gonna throw in the standard cam to see what that does, failing that gonna chuck in a wrecker engine using the cam and see what that does. have run a scan tool on it to find a fault with the tps, map sensor and knock sensor, changed map and reset tps values, which has fixed those fault codes, so what should i do?

i am thinking that the rings have been but in upside down....

no dont think its a ring issue, was wondering if there is supposed to be a gauze inside the rocker cover under the pcv, i pulled the pcv out and could see straight down onto a valve, so im thinking that the vaccume on decel might be sucking oil straight down to the manifold causing the smoke, so have change rocker cover to an au 1 which has a plate covering the bottom of the pcv to see if this fixes the problem, time will tell i guess, just waiting for the oil left in the bottom of manifold and cat to burn out completely to see

You should have clicked when the guy wanted to swap a manual xr6 for a magna

lol, nah he is my boss and was just too impatient to work out what is wrong, and wanted something he could put his dogs into to go to the beach, and even if i have to put in a wrecker engine till i sort out this issue its still a better car than a magna

does she breath heavy through the rocker cover breather ??
3 easy ways of oil getting burn is
1. rings on upsidedown / broken
2. gaskets not sealing
and lastly stem seals or crack in the head

was their any head work done?
you say its built for turbo use, what is the compression ratio ??

i havent done alot of work with petrol motors as i work on diesel but on decel the butterfly is closed and the breather is before the butterfly closing so its pretty easy for when the piston moves down to suck through the head

rings upside down possibly but not likely done twice, not likely to be gasket as this has been done 3 times, and original thought was stem seals but the head was done at time of rebuild and it is fouling all the the plugs which will rule out a dodgy stem seal or crack as its isolated to 1 or 2 cylinders. not sure on compression ratio but has good even compression across all 6 cyls. there is a lot of vacume at the pcv and there is no blo by, ran it for a day with no pcv or rear breather hose connected and it is still clean on the outside so thats a good sign, engine has just clicked the 10000km mark since build and has plenty of go, ( bye bye to 2 turbo manual 32's and an auto 220kw au xr8 on the weekend ) all that i can think of now is to remove the cam and go back to stock to see what happens