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kev87 |
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g'day
almost finished my turbo project and gets tuned in 2 weeks BUT i hav come across a problem with oil coming out the dipstick at about 2 grand. its a fresh motor so there is not blow by and ive pin pointed the problem to the crankcase ventilation system. does anyone have any good and simple ideas to resolve this?? ive put a diagram which i think mite work but if anyone thinks it wont please modify the pic so i can work off it thanks heaps!!!!
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EBXR8380 |
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I would do the PCV to take manifold vacuum as it has one way valve ...
Then fit the other to inlet pre turbo.. If not you'll boost crankcase... Its best to take rocker cover off and drill out the rear vent as they are alittle small for forced induction... A one way valve from most Jap wrecks fitted inline with both brake booster and PCV just to be safe... With the way you have it.. It doesn't vent anywhere while engine is under boost... Remember the PCV closes under boost... Or it should....
_________________ As in ZOOM 126 edition |
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fritzz |
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kev87 |
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fritzz |
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haha, i think u got the wrong idea about crankcase ventilation.
u dont want any boost in there.
_________________ # 1997 EL Falcon GLI - 600+rwkw |
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kev87 |
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hang on another thing. ebxr8380 said that the pcv valve closses under boost pressure. which must mean there is very little vacuum draw through the pre turbo hose??? is that right??
cos if theres mass amounts of vacuum it'll pull thru the dipstick and worst case thru the seals.. just trying to b cautious lol |
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fritzz |
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the pcv valve closes when the boost from the plenum try the go bak thew the pipe and into the crank case. it opens when the plenum gets vacuum to stop stinky gases going to atmo.
yes there is very little vacuum pre turbo.
_________________ # 1997 EL Falcon GLI - 600+rwkw |
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kev87 |
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k now i kno the theory behind it. thanks heaps
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blinkAU |
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I had this same problem had it blowing oil out the dipstick. Mine is now setup simliar to the pic you originally posted
Actually here is a pic of it which may help you http://i3.photobucket.com/albums/y67/au2/m1.jpg |
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kev87 |
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yeah but wudnt the crankcase b getting constant pressure on and off boost? cant b good for seals? but then again u wudnt hav it if it didnt work effectively
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tjb45 |
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fritzz's diagram is the correct way. Off boost the PCV will work to provide suction from the crank case to the inlet manifold. When on boost the PCV will close and the rear vent will then provide the suction from the crank case through the catch can to the front of the turbo.
I would recommend getting a metal PCV, as the plastic ones have a habit of breaking, also it might pay to get an addition one way valve to put between the PCV and the inlet manifold as often the PCV valves done seal 100% and will cause pressurization of the crank case This is important to get right, under extreme situations pressurization of the crank case can slow the oil feed through the turbo. Good luck. |
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ISQUIK |
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kev87 |
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that will do absolutely nothing. nothing is flowing so no crank case gasses wud be vented and theres no need for a catch can.
ive been studying up a bit and found out the best way for a crankcase to b in is full vacuum, so theres no pressures against the moving internals. most dragscars hav a pump of sum sort to keep it in this state. |
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fritzz |
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{USERNAME} wrote: wat about this kind of setup
[/img] that would be ok, if the catch can had a filter on top. but would do nothing at all if it was a sealed catch can.
_________________ # 1997 EL Falcon GLI - 600+rwkw |
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EBXR8380 |
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Some vacuum to crankcase helps purge condensation from oil etc keeping it clean...
If engine is in good nick then PCV could stay as is.. Then vent rear breather to air cleaner cover where fumes finally get sucked into air cleaner... If this breather line is high enough on firewall there very little chance of oil going through it... The better the ventilation the better the ring seal...
_________________ As in ZOOM 126 edition |
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