proxlamus© Posted May 2, 2007 Share Posted May 2, 2007 Well, I have owned 2 Z motors now, a N42 block and a F54 block. I have been having major issues with smoking pouring out of the exhuast and I am burning oil. When running an N42 intake manifold, and a turbocharger unfortunatly I am unable to used my PCV (positive crankcase ventilation) valve on the bottom of the intake manifold. This uses the intake to create a vacuum in the crankcase of the engine and create a good seal between the rings and also pull oil from the turbo. Alot of Z guys just run the crankcase breather tube and valve cover breather OPEN or with a filter. One problem is engine breaths.. literally.. and all the blow by and crap in the crankcase goes OUT. this clogs the filter which increases positive pressure. continue reading why this is bad. Positive pressure is bad. why? When the crankcase is pressurized, there is so much pressure, the oil trying to drain out of the turbocharger can't fall into the oil pan. It has no where to go but back up and OUT! This overloads the oil seal, and the oil seeps into the exhuast and turbine blades. The heat from the turbo and hot exhuast causes the oil to smoke and burn, resulting in a cloud of smoke. Typical signs of this include - NO smoke on start up. Lots of smoke once the exhaust warms up. Oil in the turbine housing and the exhuast. BLUE smoke. Clean spark plugs. Clean intake piping. Has anyone else experienced this? or am I the lucky one to get it twice in a row on two seperate motors. Quote Link to comment Share on other sites More sharing options...
george.bryant Posted May 2, 2007 Share Posted May 2, 2007 yes i experience it everyday. i have my block and rocker cover breathing and i hate it, as does my engine. because of my large turbo i cant use the factory pcv calce location under the inlet manifold and ahve yet to remove the manifold and drill/tap a new location for the pcv valve. i cant wait to get this done. the motor chews thru oil also and deaccelerating is nasty! Quote Link to comment Share on other sites More sharing options...
Tony D Posted May 2, 2007 Share Posted May 2, 2007 WHY in the world don't you simply tap the lower section of the manifold and install the PCV? That's what I did on several cars. If you have the turbo manifold around when you do the swap, it makes a nice template for locating the hole. Failing that, you can stick the PCV in the stock turbo PCV Hose and kind of line it up to where it needs to go. BTW, under boost, PCV is provided by the turbine inlet suction and the differential across the air filter... The normal plenum PCV is acting as a check-valve preventing boost from blowing directly into the crankcase. If you have excess pressure after making the modifications, more than likely it's 'ring time'... as well as 'ring land time'... Quote Link to comment Share on other sites More sharing options...
Pop N Wood Posted May 2, 2007 Share Posted May 2, 2007 A lot of turbo guys use these. do a search on ls1tech.com if you want real world testimonials. http://store.summitracing.com/partdetail.asp?autofilter=1&part=MOR%2D25900&N=700+400105+115&autoview=sku Quote Link to comment Share on other sites More sharing options...
JMortensen Posted May 2, 2007 Share Posted May 2, 2007 A lot of turbo guys use these. do a search on ls1tech.com if you want real world testimonials. http://store.summitracing.com/partdetail.asp?autofilter=1&part=MOR%2D25900&N=700+400105+115&autoview=sku The Mr. Gasket part is about 1/2 the price of that Moroso part. Jeg's has them. Quote Link to comment Share on other sites More sharing options...
cygnusx1 Posted May 2, 2007 Share Posted May 2, 2007 What are the two pods that sit on the valve cover? Are they air/oil separators? I suppose you would connect the valve cover AND the block breather to the slashed tube in the exhaust. It probably wont make much vacuum at idle though. That looks like it can be fabbed up pretty easily. Another worry would be that you need to do this at least 12" downstream of the O2 sensor for obvious reasons. Quote Link to comment Share on other sites More sharing options...
aarang Posted May 2, 2007 Share Posted May 2, 2007 If you want to put your PCV valve in the stock location of the N42 manifold, you can go to the hardware store and get a brass 1/4 NPT 90 deg elbow. I did this and aimed the PCV valve at the valve cover. The PCV valve to manifold is hooked to the valve cover, and the block breather is hooked before the turbo. I still was getting some oil in the intake, so I put a catch can in between the block breather and the tube before the turbo. If you don't want to use the elbow above the turbo, you can drill and tap the heat shield boss that is right in front of the stock PCV location to 1/4 NPT and put it there. I had my PCV valve there at one time, but now I use that as the vacuum source for my BOV. Hope that helps!! Aaron Quote Link to comment Share on other sites More sharing options...
proxlamus© Posted May 3, 2007 Author Share Posted May 3, 2007 i bought an INLINE PCV valve today and used a plugged port. car still smokes. this sucks Quote Link to comment Share on other sites More sharing options...
510six Posted May 3, 2007 Share Posted May 3, 2007 First, are you sure your turbo`s oil seal is good.This will only appear when letting off the throttle after boosting.A friend who is an aircraft mechanic made a aircraft style air/oil seperator and it has eliminated any blowby problems assosiated with boost. http://www.aircraftspruce.com/menus/ep/airoilseparators.html Quote Link to comment Share on other sites More sharing options...
cygnusx1 Posted May 3, 2007 Share Posted May 3, 2007 Here is how I got my stock PCV to fit in the stock L28ET manifold with a larger turbo. Quote Link to comment Share on other sites More sharing options...
GrommitZ Posted May 3, 2007 Share Posted May 3, 2007 Are you running a hose from the valve cover breather in front of the compressor like stock? This should help reduce crank case pressures and oil blowby in the turbo even when the intake manifold pressure is positive. Quote Link to comment Share on other sites More sharing options...
G.I.jonas Posted May 3, 2007 Share Posted May 3, 2007 i bought an INLINE PCV valve today and used a plugged port. car still smokes. this sucks How long are you giving the fix to work?,maybe you have residual oil still burning? Quote Link to comment Share on other sites More sharing options...
RB26powered74zcar Posted May 3, 2007 Share Posted May 3, 2007 The Mr. Gasket part is about 1/2 the price of that Moroso part. Jeg's has them. Jon, from your experience, would it be best to; pull vacuum from the block vent pipe, with a filter on the valve cover vent pipe? or pull vacuum from vent pipe on valve cover, and put filter on block vent pipe? For helping ring seal, does it work better, one way over the other ?? Quote Link to comment Share on other sites More sharing options...
JMortensen Posted May 3, 2007 Share Posted May 3, 2007 Jon, from your experience, would it be best to; pull vacuum from the block vent pipe, with a filter on the valve cover vent pipe? or pull vacuum from vent pipe on valve cover, and put filter on block vent pipe? For helping ring seal, does it work better, one way over the other ?? I have no experience other than buying the parts. Haven't gotten around to installing them yet. My plan was to run the tube off of the block breather, and either cap or restrict the valve cover orifice. There is a bit in the How to Modify book about running too much vacuum and having the rear main suck in and allow oil out the back of the engine. That is my major concern. I think I'll run the valve cover totally blocked and then if it smokes I'll drill a small hole to limit the vacuum and see if that does it. Quote Link to comment Share on other sites More sharing options...
proxlamus© Posted May 3, 2007 Author Share Posted May 3, 2007 Well I pulled the plugs, no oil on the plugs.. so i'm not burning oil in the cylinders. as for the turbo, the compressor housing and intake piping is clean with no oil residue. the turbine housing is coated in oil. I checked the drain line, I installed the PCV which is workn, as I can hear it hissing when I pull the oil dipstick. Oil smokes at idle, and on deceleration. pretty blue smoke, and only when warmed up. anything else i can try? Quote Link to comment Share on other sites More sharing options...
cygnusx1 Posted May 3, 2007 Share Posted May 3, 2007 My new plan...it has changed a dozen times...is to leave the stock PCV valve in the manifold, with the fitting arrangement I posted above, to suck on the block vent during vacuum conditions. Now, instead of just leaving the valve cover vent filtered to atmoshpere, I am going to shove a piece of steel tube into the downpipe and connect that to the valve cover through a check valve. My thinking is: -Under cruise with high vacuum, the block vent will be put under vacuum from the intake through the PCV valve. -Under boost, the PCV valve shuts, the downpipe will create vacuum and suck on the valve cover vent. This will put the crankcase under vacuum at all times using two different sources. If I get too much vacuum I can tweak things. Quote Link to comment Share on other sites More sharing options...
proxlamus© Posted May 3, 2007 Author Share Posted May 3, 2007 I called Garret (yeh i have a holset but anyway) they recommended I get an oil restrictor.. maybe down to like .120 or .080 Quote Link to comment Share on other sites More sharing options...
proxlamus© Posted May 10, 2007 Author Share Posted May 10, 2007 Ok.. I added an oil restrictor.. no change I added a large PCV setup.. no change spark plugs are clean, compression numbers are fine across the board. Minimal shaft play.. What the hell is going on??! Quote Link to comment Share on other sites More sharing options...
cygnusx1 Posted May 10, 2007 Share Posted May 10, 2007 Maybe the bearing in the turbo is still good but the seal is bad? Quote Link to comment Share on other sites More sharing options...
proxlamus© Posted May 10, 2007 Author Share Posted May 10, 2007 well the turbine bearing is METAL so unless there is tons of shaft play, there should be no reason to smoke. I could have blown the rubber o-ring.. but damn.. i dunno Quote Link to comment Share on other sites More sharing options...
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