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Engine Specific Info and Questions => IDI Engine => Topic started by: spencebm on October 21, 2009, 07:41:21 pm
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How do you boosted guys deal with your blowby? I don't want to run mine back in the engine but I consume oil when it is dumped to the ground. I really don't want to go to a catch can so what is everyone's opinion on this? I use the stock td air/oil puck on the valve cover and vent it to the ground. Also, what harm is coming to the turbo if it is dumped back into the intake before the compressor? Let the discussion begin!
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i went from the VC, to a self fabbed oil separator can. then it goes to the intake. im pretty sure nothing bad happens to the turbo when it inhales blow by. every single turbo diesel inhales blow by. i just wanted to cut down on the amount of oil entering my turbo, and the oil separator works nicely. i used to consume alot more oil. because on boost i used to have so much blow by that there would be so much oil in the blow by that it would drip from the turbo.
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Too much blow-by sent to the intake can cause run-away, be careful. You need some sort of oil separation if you are going to route it back to the intake.
Brendan
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Another suggestion, that eliminated oil from my gasser engine, was putting a breather/vent where the "puck" currently is and running the hose that sucks the blowby or engine gasses in the crank-case to the little plate beside the oil filter mount. I plan on doing this once I get my TD back together.
I think this is a better place to put it as the blow by does not end up in the head, but in the crank case.
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yea, but more oil vapor gets trapped in the air if you take it directly from the crank case... if it goes up through the head and stuff, the oil has time to stick to things and then run back into the engine.
and you dont have to worry too much about blow by, my audi makes as much blow by as it does exhaust, and uses a quart of oil in under 100 miles. thats some pretty bad blow by if you ask me, and its never run away. *knocks on wood*
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The main reason I ask is that I want to keep oil consumption down as much as possible. The "puck" seems to do little to nothing in terms of slowing blowby so I would like to get rid of it and just have an oil/air separator with a breather filter but I think that may stink up the engine bay with rotella T fumes. What do you guys think about that and what do you recommend for media to separate oil from air? Thanks for your input.
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heavy steel wool in a can does a good job, just make sure not to pack the can too tight and restrict the gasses flow out of the engine block(or its bye bye seals)
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I have a crankcase vent system from Summit that I'm really seriously considering on the Wife's car. It's a bung you weld to your exhaust, with a check-valve, and you run a hose from that to your valve cover. It's a V8 kit, so I have two of them, if it works well on her car then I'll put another one on the Scirocco. :)
Anyone else run one of these?
Brendan
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Just remember that the valves in these things is supposedly in need of the oil mist from the intake track. So a catch can idea up several posts isn't a good idea, but the separators and such seem good to me. I am going to put a T in and run one to the crankcase and one to the intake track...see what happens.
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Just remember that the valves in these things is supposedly in need of the oil mist from the intake track. So a catch can idea up several posts isn't a good idea, but the separators and such seem good to me. I am going to put a T in and run one to the crankcase and one to the intake track...see what happens.
Really? I never heard that. I have been running a road draft tube for quite some time now. What should I be watching for to indicate valve issues due to lack of oil mist blowby?
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Dont bother with the dumping into the exhaust thing. I tried everything on my d24 to not put it back into the intake, but ended back there anyway. If you go to the exhaust, it will more white than it already does, and when you get under boost you will push oil and white smoke like you wouldn't believe. I think it was actually sucking oil out of the valve cover when I had it set up that way. A catch can is nice but thats a PIA cuz you have to drain it. I built my own seperator with an internal baffle, along with a drain in the bottom to go back to the oil pan. It cut down on oil into the intake in at least half or better. I didn't have any steel wool laying around but I'm planning on stuffing some in it to help it catch more.
http://d24t.com/showthread.php?t=107
theres a link to the writeup I did with some pictures.
Jason
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Just remember that the valves in these things is supposedly in need of the oil mist from the intake track. So a catch can idea up several posts isn't a good idea, but the separators and such seem good to me. I am going to put a T in and run one to the crankcase and one to the intake track...see what happens.
Really? I never heard that. I have been running a road draft tube for quite some time now. What should I be watching for to indicate valve issues due to lack of oil mist blowby?
It's in one of the VW SAE papers (can't remember if it's the 1.5 or 1.6 paper) - apparently the VW engineers thought it was a good idea.
I guess I can get behind that - with leaded fuel and a gasser the lead was supposed to provide a "cushion" for the intake valve. When you took the lead out of the fuel you needed better valve seats. Stands to reason that if you can lubricate the intake valves with blowby oil mist then you'd be better off than having them "dry"...
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I've been looking at a Mann Hummel Provent 200, kind of a lot of money :'(
If one of these filter/separators was used is there any need to keep the original CCV?
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Brendan, that Summit setup you have is for open headers on drag race cars. It uses exhaust velocity to created crankcase vacuum to allow light tension rings to seat better. Wherever you plumb it into your exhaust is going to get filled with oil and if the cross section is wrong (too big) you won't get the vacuum effect. It's intended to go into the header merge collector on high end headers with short secondaries around a foot long or so. Usually for trailered "track queens" only.
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i vote for an oil separator with the outlet plumbed back into the intake. why does everyone not like there crank case gasses going back into the engine? what the hell is the matter with it? diesels burn oil. it will probably give another HP or 2 with that fine oil mist going into the intake also. every diesel vw ever made inhales crank case gasses. its just oily exhaust basically. whats the problem? im just trying to figure out why everyone is against just routing it back to where it goes? i just through a catch can/separator in the mix also. worked great.
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i vote for an oil separator with the outlet plumbed back into the intake. why does everyone not like there crank case gasses going back into the engine? what the hell is the matter with it? diesels burn oil. it will probably give another HP or 2 with that fine oil mist going into the intake also. every diesel vw ever made inhales crank case gasses. its just oily exhaust basically. whats the problem? im just trying to figure out why everyone is against just routing it back to where it goes? i just through a catch can/separator in the mix also. worked great.
I am venting it because over time in restricts the intake passages. The inside of my intake is pretty nasty and if it were not for the nuts holding it to the head are corroded in place I would have pulled the intake off and cleaned it.
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Remember we are talking about BOOSTED applications only and I am unsure about running it back into the turbo because I don't like the idea of oil droplets hitting my compressor blades at 25 psi so maybe we could discuss early compressor failure due to excess oil? Thanks for the input guys.
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dude, lots of engines have oil droplets hitting the turbo at 25 psi. including mine, and probably most of the builders here. i have a 1.5, so you can just about imagine what i have to deal with. the 1.5's are notorious for having the worst blow by of all VW diesels. and mine is boosted, at right around 25psi no less.