Intercooler If Filled With Oil
11-26-2008, 04:05 PM
#41
ahh I see. not any active venting as with a vacuum source on an turbo/sc inlet, but just easier evacuation of pressure. Interesting.
So either an aftermarket 1 way valve to completely stop boost entering CC or, larger less resistance path for boost to exit.
So either an aftermarket 1 way valve to completely stop boost entering CC or, larger less resistance path for boost to exit.
Sharif's setup doesn't keep boost out of the crank case. Nothing will keep blowby out of the crankcase. The point is venting the crancase to relieve the crankcase pressure.
One of the issues with the stock setup is that the hole in the drivers side breather is tiny, smaller than a drinking straw. Drilling that out and opening it up will alow more volume out of the crankcase more efficiently relieving pressure.
Under boost the pax side PCV valve is closed so there is no venting throug hthe PCV into the plenum. The two valve covers are joined by a crossover hose of small diameter that vents the pax side valve cover pressure into the drivers side valve cover and out the drivers side valve cover breather into the intake.
There is no way that hole is big enough to evacuate all the crankcase pressure built up. Crankcase pressure starts to blow out through mating surfaces like where the lower oil pan joins the upper oil pan, and presurizes the oil return lines causing pressure and oil to leak out the oil seals on the turbo. It's not a good thing.
Sharif's system is simple. It does away with using the small diameter valve cover crossover as the only source of removing pax side crankcase pressure. The drilled out PCV valve is the new point of evacuation for the pax side valve cover. Thee drilled out drivers side breather hole can move more volume. The crossover is now only responsible for equalizing the pressure between the valve covers.
This does away with the recirc of the crancase vapors into the plenum.
This setup is not as good as having a good vacuum source hooked up, but this might be all we need to stop the leaks.
Has anyone thought about my suggestion of drilling the upper oil pan and venting the crancase there? Maybe there is somewhere else on the crancase to vent from?
One of the issues with the stock setup is that the hole in the drivers side breather is tiny, smaller than a drinking straw. Drilling that out and opening it up will alow more volume out of the crankcase more efficiently relieving pressure.
Under boost the pax side PCV valve is closed so there is no venting throug hthe PCV into the plenum. The two valve covers are joined by a crossover hose of small diameter that vents the pax side valve cover pressure into the drivers side valve cover and out the drivers side valve cover breather into the intake.
There is no way that hole is big enough to evacuate all the crankcase pressure built up. Crankcase pressure starts to blow out through mating surfaces like where the lower oil pan joins the upper oil pan, and presurizes the oil return lines causing pressure and oil to leak out the oil seals on the turbo. It's not a good thing.
Sharif's system is simple. It does away with using the small diameter valve cover crossover as the only source of removing pax side crankcase pressure. The drilled out PCV valve is the new point of evacuation for the pax side valve cover. Thee drilled out drivers side breather hole can move more volume. The crossover is now only responsible for equalizing the pressure between the valve covers.
This does away with the recirc of the crancase vapors into the plenum.
This setup is not as good as having a good vacuum source hooked up, but this might be all we need to stop the leaks.
Has anyone thought about my suggestion of drilling the upper oil pan and venting the crancase there? Maybe there is somewhere else on the crancase to vent from?
11-26-2008, 04:31 PM
#42
The boost is entering the crankcase in the form of blowby past the piston rings. There is no way to stop that. You have to have an efficient way of venting that crancase pressure to the atrmosphere. The OEM system wasn't designed with that in mind.
Last edited by JETPILOT; 11-26-2008 at 04:34 PM.
11-26-2008, 04:56 PM
#43
hmm how do stock turbo cars deal with this like subi's etc? doesnt seem that belt/electric vac pumps are common?
people are puttin 1 way valves (or even the stock PCV) on the pax side to prevent boost from entering the CC.. is that to prevent additional boost other than ring blowby?
people are puttin 1 way valves (or even the stock PCV) on the pax side to prevent boost from entering the CC.. is that to prevent additional boost other than ring blowby?
11-26-2008, 05:45 PM
#44
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This is of topic but Im hoping you guys can help. Ran over some type of hole cover at the gas station and i heard a loud clank. Now Im leaking a tiny bit of oil. Its almost on the rear passenger jack position. There is a metal plate and its got a small nick in it. The oil is coming from the side of the top of the plate though. I have to go to work so I cant mess with it now. What do you guys think it is or what is that metal plate connected to or covering. Plate is closer to the back of the passenger door under the car.
11-26-2008, 05:59 PM
#45
hmm how do stock turbo cars deal with this like subi's etc? doesnt seem that belt/electric vac pumps are common?
people are puttin 1 way valves (or even the stock PCV) on the pax side to prevent boost from entering the CC.. is that to prevent additional boost other than ring blowby?
people are puttin 1 way valves (or even the stock PCV) on the pax side to prevent boost from entering the CC.. is that to prevent additional boost other than ring blowby?
Remember the PCV valve is only venting under vacuum. Under bosot the PCV valve is closed and might as well not even be there which is the situation we have when we boost the VQ. The VQ35 under WOT was designed to have the PCV valve be fully open and vacuum from the plenum creating crankcase ventilation. The VQ35 PCV system was never designed to see anything but vacuum. In NA form in case of a backfire the PCV will close but that's about it.
11-28-2008, 11:50 PM
#47
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hmm how do stock turbo cars deal with this like subi's etc? doesnt seem that belt/electric vac pumps are common?
people are puttin 1 way valves (or even the stock PCV) on the pax side to prevent boost from entering the CC.. is that to prevent additional boost other than ring blowby?
people are puttin 1 way valves (or even the stock PCV) on the pax side to prevent boost from entering the CC.. is that to prevent additional boost other than ring blowby?
11-29-2008, 09:51 PM
#52
I don't get the humor. I think it sounds like a good idea! Am I missing something? 
Definetly keep us informed how this turns out. Try running it open first with a hose going to a catch can and see what happens.
Definetly keep us informed how this turns out. Try running it open first with a hose going to a catch can and see what happens.
Last edited by JETPILOT; 11-29-2008 at 09:54 PM.
11-30-2008, 12:08 AM
#55
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http://www.honda-tech.com/showthread...tion+crankcase
You will see upon reading that the amount of vacuum available is not even and dependable and I am far from recommending it ...
After reading this thread through it gives you a whole bunch to think about ...
Last edited by cersoft; 11-30-2008 at 12:30 AM.
11-30-2008, 12:39 AM
#56
I believe that the method being refered to is 'Exhaust slashcut evacuation" as mentioned in this thread :-
http://www.honda-tech.com/showthread...tion+crankcase
You will see upon reading that the amount of vacuum available is not even and dependable and I am far from recommending it ...
After reading this thread through it gives you a whole bunch to think about ...
http://www.honda-tech.com/showthread...tion+crankcase
You will see upon reading that the amount of vacuum available is not even and dependable and I am far from recommending it ...
After reading this thread through it gives you a whole bunch to think about ...
Last edited by Havok_RLS2; 12-01-2008 at 11:25 PM.
11-30-2008, 01:40 AM
#57
For REAL? You really don't see the humor? I thought you were one of the smarter guys on this forum, someone I could look up to. How could you NOT think that idea is anything other than funny? 
I honestly thought str8dum1 was was joking and not just being... Well... Straight Dumb. OKay.
Now I'm not trying to be a complete a$$ (through my wife says I'm quite good at it) and I want to see a solution to this problem just as much as anyone as I too have a FI Z. But really?
Unless I missed something str8-dum-1 suggested "He should tap his exhuast and run a hose from the exhaust (< I even quoted his misspelling)to the CC with a 1 way valve".
Now let me explain what I read in funny boys post:
"should tap your (Extremely HOT rubber and plastic melting exhaust) and run a hose (probably made of rubber or plastic) from the exhaust to the CC with a 1 way valve (that could fail due to the extream heat or any number of other things). Have I missed anything? I say again.
This is not a wastegate. There are a number of things that haven't even been considered for something this dumb to even work never mind finding his so-called "Hose" made from Unobtainimu and his super-duper Intelligent Check Valve that can tell the difference between Positive Crank Case Pressure and Back Pressure.
PLEASE someone tell me what you think would happen if said check valve FAILED open allowing exhaust gasses into CC? PLEASE someone tell me what is the pressure variance between the CC at any rpm and the backpresure readings in a exhaust system with CATs in place?
Answers anyone?
Now JETPILOT, I'm going to assume that IQ's higher than 80 are required for being jet pilot so now I'm going to assume you understand why I thought it was funny now. Then you know what say about people who assume right? make and A$$ out of U and ME
Yep I say again
How about we find another idea that doesn't involve Getto-Rigging a thirty thousand dollar car?
It's not a Honda civic.I say all that with the utmost respect.
11-30-2008, 01:53 AM
#58
People seem to think that there needs to be a source of vacuum for crancase evac to work. There doesn't. There needs to be a source of comparably lower pressure which is the atmosphere. As long as there is higher pressure in the crankcase it will seek lower pressure through a vent as long as it is large/efficient enough. I think the crankcase vent hole could work without a vacuum source as long as it doesn't see oil as it returns to the pan or as it sloshes around in turns.
11-30-2008, 04:25 AM
#59
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Jet isn't that a drag car? It may work there but a car that is driven on, to, from, dd, a track it may not work. Is there a check valve on that line? What would stop your exhaust gases from coming back into the line and the engine? Lets not go with out the header, we all have some kind of exhaust.
11-30-2008, 04:49 AM
#60
I have no idea if the exhaust evac would work on our car. I certainly don't know if you would neeed check valves. I never attempted this on my 350Z. I had it on my Grand National which was driven on the street and I had no check valves. No one runs check valves on these systems. Yes those are drag cars.
Like I said. There does not need to be a source of vacuum to accomplish what we want to do. Only a source of lower pressure than the crankcase which is the atmosphere.
Like I said. There does not need to be a source of vacuum to accomplish what we want to do. Only a source of lower pressure than the crankcase which is the atmosphere.