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Old 03-01-2007, 06:18 PM   #1
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Default Exhaust venturi vs pcv system

OK, I have been wanting to do something different with my PCV system for a while. Currently I have a small K&N filter on the drivers side with a pcv from the pax side to the intake manifold. My car has some blowby (or possibly a leaky turbo seal) so I get a puff of smoke every time I let off the gas (I think that is when it happens). I don't want that crap getting into my cylinders any longer so I am thinking of venting everything to the exhaust.

Can anyone see a problem with this setup:

Keep my drivers side intake K&N filter in place. Cap off the hole in the intake manifold. Run a hose from the pcv valve under the car to the exhaust downstream of my downpipe. Cut an angle on a small pipe and weld it at an angle a little downstream if possible of the WBO2 bung (not much room to work with):
http://ww2.lightweightmiata.com:8080...exhaust06a.jpg

Would my hose melt (probably very small heater hose) if my small pipe was only 2-3" long? I would probably "repack" my cam baffles or put a small catch can somewhere to keep the oil from exiting the exhaust if it became a problem.
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Old 03-01-2007, 06:40 PM   #2
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Check out this link, http://www.honda-tech.com/zerothread?id=1199935
There is a moroso part in there for doing the exhaust slashcut/venturi system. It incorporates oneway valves.

I'd suggest if you want to go that route... run a catchcan in between. Use the slashcut to pull vacuum, and the catchan to accumulate the junk from the breather.
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Old 03-01-2007, 07:59 PM   #3
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The angle and position of the pipe have to be just right to achieve a a strong ventruri effect. I don't think it's as simple as sticking a tube into the exhaust stream. If you have a cat oil contamination could lead to an early death.

Is it possible that the puff you are seeing is actually the result of a very rich AFR? While doing intial tuning, I was creating a nice black cloud running 10.5:1 AFR.
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Old 03-02-2007, 09:09 AM   #4
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Quote:
Originally Posted by mschlang View Post
The angle and position of the pipe have to be just right to achieve a a strong ventruri effect. I don't think it's as simple as sticking a tube into the exhaust stream. If you have a cat oil contamination could lead to an early death.

Is it possible that the puff you are seeing is actually the result of a very rich AFR? While doing intial tuning, I was creating a nice black cloud running 10.5:1 AFR.
I am a novice welder so any mistake I make with the position is just an excuse to play with my mig welder again.

Yes, it could be fuel BUT my A/F looked good the last time I checked. I'm trying to use the exhaust vacuum route to eliminate all possibilities on what the smoke is.
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Old 03-04-2007, 04:38 PM   #5
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blue smoke is oil....

Means normally (non turbo) that the valve guides are out off specs...(only blue when lifting the trottle)

All the time blue: deffect turbo or piston rings.

To check: remove downpipe look for oil. (turbo deffect)
Check intake (oil on butterfly valve means turbo too.)

Replace pvc valve (just 2 b sure)
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