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Pfft thats the silliest thing ive heard, where the **** does the air fuel come from. Its only air :[ FFs some pplz that make the rules got no idea. Pressureized air intake does not contain fuel or oil and how can fuel get back that far theu the manifold to the BOV when pressurized. ROFL. Normaly aspirated cars do that if they have a BIG cam with lotsa overlap but not turbo. They call it "reversion" u can even see it on my car without the air filters off but ide rather keep them on. ADRs r BS for cases like that. Most times the aftermarket items r much better quality and r safter than most stock chepo items. just think of it like i do, the GOV has their hand out for any $$$$ they can get to pay off forign debt. One reson i dont own a Skyline Sif put up with all that BS from them so i can pay them more money.

erm hate to tell you brad but it does contain Oil.....

Thats what Catch Cans are designed for.

To prevent oil sludging up your IC & allowing oil vapours to enter your combustion chamber etc etc.

I'm not to sure about fuel vapours but then again it does seem logical as what happens to cars that are driven on short trips only? Their oil starts to get contaminated with fuel. Only by a small amount but its still there I guess.

Raises a point I didnt think about, as road traffic act requires all crankcase fumes to go through the plenum, if a BOV vents to atmo, spose they arent getting to the plenum even if you use a catch can.:) Got us on that one, but I bet not too many cops would think of that one.

Originally posted by GTR King

Fuel in Oil is from Blo by past the piston rings, Joel can u tell me where oil can get into the intake manifold. Got me stuffed what u r on about.

Brad...

A oil catch can is to prevent oil ingestion in to the turbo and intake.

Similiar to when a motor is breathing like fark and you see oil splattered all over your air filter (in a carby car) 626 Mazda for example.....

You didn't know that?!?!?!?!?

Do a little bit of a search with regards to why catch cans are fitted and how detrimental not having one on a boosted engine can be when driving it constantly hard.

It can also occur when the turbo's compressor oil seal is stuffed.

Joel, I think the problem is that GTR King is maybe used to old school (pre emission) cars - the crankcase gasses are vented to atmosphere via the oil filler cap, just a pipe from the crankcase to the rocker cover, and mesh in the filler cap with a hole up the middle - bit like fitting a atmo rocker cover vent on a skyline.

GTR King, to carry on from what Joel is saying, the crankcase gasses on a skyline goes straight into the plenum when not on boost, when on boost, as the plenum is pressurised, the gasses get plumbed back into the airpipe that connects the afm to the turbo - this then coats the turbo and cooler in a slick oily coating - especially if you have a bit of blow by, or are running increased boost without a catch can. This has potential for causing detonataion too, as you may be able to imagine.

When I took my stock cooler off, the inlet side was black, the other side was grey/normal - this was with stock boost - pretty shit really:(

yeah, what Steve and Joel said :D

I often give my blow-off valve a bit o a wipe and always get plenty of oil off it (and other lubricants by the smell of it). I don't understand why, I just know it's there ;)

Yeah even my car has vented crank case and a catch can:] Tho old school cars did have PCV valves in the Rocker Cover back tho the Inlet Manifold. Didnt think Intakes on Skylines would have recirculation as i chums up the throttle bodys and Map sensors etc. Tho i forgot about oil seals on turbo main shafts, tho if they r leaking u deffinatly got a prob :[ Man i got stop saying that word Turbo, just makes me wanna buy one.

Originally posted by TIMMMAYYY

PCV valves? vented crank cases? Catch Cans? Oil coming out of BOV"s?  Im confused :D

No worries, will do my best to explain:

PCV valves - Positive crankcase ventilation valve. Positive crankcase ventilation, is the removal of gasses from the crank case (which are caused by gasses from the combustion process being forced passed the cyliners, called blow by). These gasses generally are vented in to the rocker cover (or cam cover). From here they go directly into the plenum when not under boost. To stop the gasses from going in the opposite direction a one way valve is used. PCV Valve.

Catch cans - when a turbo car is under boost, the gasses from the crankcase (the blow by) cannot go into the plenum as it is pressurised, so they are plumbed into the intake before the turbo. Blow by is made up of combustion gasses, contaminated with oil and a small amount of fuel. This goes throught the turbo, intercooler, BOV (oil coming out of BOV)when venting and eventually into the cyliners to be burnt - pollution control. A catch can fits between the cam cover and the intake pipe to the turbo, and removes by filtering, the oil and particles suspended in the blow by.

Hope that makes sense

yeah RB30 would be the go but i wanna keep it sorta origional looking. Turbo make huge underbonnet heat and i dont wanna have to vent my bonnet or wreck my paint. My old man is building a 600hp+ rb30 for his co drivers new EH drag car hes building. See how that goes first then ill decide. Supercharged Methanol sucking rb30. Should be running Mechanical fuel injection. None of this expensive computerised stuff, who needs it :[ Cant wait to see how it goes. Tho it aint very aerodynamic. It will be a full chasis car tho.

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