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provent 200 instead of cdr?

Will L.

Will L.

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I already bought a provent 200. I was thinking eliminate the cdr and only use the provent.

A mistake? We, as in fleet, done it before making my own catch can. I never noticed a problem but also never looked really hard for one. Should I run the cdr and provent? No blow by at the moment, but It does drink a bit of it's own oil which I would rather keep in the pan instead of the intake.

I don't want to vent to atmosphere, $10,000 fine is not enticing, and If I can keep trees healthier so I have something to chop down later for camp fire wood that's good to. Also, the provent will have it's breather hole go to the air intake post air filter for when I take the hummer swimming. The rest of the Hummer has all the cases sealed and vented to fresh air above the water line.
 
Will my comment in the other thread was not about which to use so much as how the CDR functions. It is totally open until a high vacuum situation occurs (usually WOT and high RPM) and then it closes so as to not put too much vacuum in the pan and unseat the rings. The small hole is to allow the diaphragm to move freely without any pressure or vacuum build up on the opposite side.
 
Based on how it works I'd think you'd want both. But I'm not real familiar with how the provent operates. I have a digital manometer if you'd like to borrow it, a normal vacuum gauge won't even come close to reading the slight vacuum in the pan.
 
Will L. said:
I already bought a provent 200. I was thinking eliminate the cdr and only use the provent.

A mistake? We, as in fleet, done it before making my own catch can. I never noticed a problem but also never looked really hard for one. Should I run the cdr and provent? No blow by at the moment, but It does drink a bit of it's own oil which I would rather keep in the pan instead of the intake.

I don't want to vent to atmosphere, $10,000 fine is not enticing, and If I can keep trees healthier so I have something to chop down later for camp fire wood that's good to. Also, the provent will have it's breather hole go to the air intake post air filter for when I take the hummer swimming. The rest of the Hummer has all the cases sealed and vented to fresh air above the water line.
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Off topic but everything I own with a waterline floats. ;) How high is the waterline on that hummer? I'll try to look up what a provent 200 is later. If I look it up now I'll probably need one. :D
 
Vacuum causing rings to unseat? Umm, no. Quite the oppposite. All serious high performance engines run a dry sump oil system and purposely run the crankcase into a serious vacuum on purpose. It is actually one of the lowest cost "free hp" alterations that can be done. Vacuum to hp is near 2:1. 8" of vacuum is good for 15 hp.
15" is around the highest that is recommended for wet sump systems that are "oil flow" modified, 10" for stock.

I have seriously considered doing a dry sump oil system in my 6.5, but $ has kept it away. Until I just mailed the vacuum pump to another member here, I was trying to decide about hooking it up on mine for creating 10-12" in my crankcase, but returning the oil requires a taping the output side of the vac pump to push it back home. Too much auto valving and time to make it work out. I'll leave the power finding dept to guys like Nate. Besides, there are jot a lot of vacuum pumps out there that don't consume a lot of power to operate and have a long life.

The power has to do the pressure differential of the chamber. The only drawbacks to vacuum in the crankcase are:
1. Sucking the seals inward or pulling in silicone causing a leak.
2. Windage of oil circulating disturbing the desired oil flow.
3. The oil mist getting pulled out of the crankcase has to go somewhere, and usually it is waste. So loss of oil from the crankcase. For street drivin rigs a 3 stage collection can system allows for reintroduced oil back to the pan, but is a fairly elaborate system.

As for the vent in the cdr needing open atmosphere to operate normal- point perfectly made- no tying into intake system. The vacuum created in the plenum and related plumbing would throw off the cdr. Going to a raised position above the waterline would allow it to operate normally.

In hmmwvs the water:air cup for pushing up atmospheric pressure when going underwater forces increased crankcase pressure so you dont have any chance for vacuum in the crankcase while it is underwater. I have been in a ton of rigs that do deep fording without a system like this, but we build the engines, and without patting myself on the back too much- my engines never leak. What most refer to as me having OCD when sealing an engine, I just call detailed. For fleet rigs like normal hmmwvs, I think it's a great idea, but I would take it further and use external pressure for low rpm moments.

The use of a provent without a cdr keeps the crankcase pressure/vacuum as close to zero as possible, but will draw more volume at higher rpm. I think thats a good thing because higher rpm causes more oil mist.

The only reason I don't see having no cdr is the increase in oil consumption. That is the point of the provent- it catches the oil and drains it back to the oil pan instead of to the intake and burning it.
 
I see no reason to keep the CDR with the PROVENT myself. GM used a similiar design to the provent on LB7 DURAMAX's with a small reservoir filled with foam to seperate the oil from the gasses, a small 1/4" line off the bottom runs back down into the timing cover to return the seperated oil, and a 5/8" line off the top runs back to vent the gasses to atmosphere. In 04.5 for the LLY+ they did away with the setup, and just had a baffle in each valve cover, a 5/8" line going to 3/4", and then it hooks into the turbo mouthpiece with no CDR or anything else what so ever in it. Many plug the turbo mouthpiece and put a piece of heater hose to it, and run the vent back down below the engine and just let it all vent out like the old 12 valves and 24 valves up to 00 did(01 CUMMINS put a small bottle on the crankcase vent filled with foam you had to empty out, otherwise it would fill up and make a mess).
 
So I was wrong. Could have sworn I read that some where. After a bunch of reading last night it appears we probably would have a hard time generating too much vacuum. The only negatives I read about was it affecting oiling as some engines seem to rely on windage to get enough oil to wrist pins etc. This makes me wonder why a CDR is used at all
 
ak diesel driver said:
So I was wrong. Could have sworn I read that some where. After a bunch of reading last night it appears we probably would have a hard time generating too much vacuum. The only negatives I read about was it affecting oiling as some engines seem to rely on windage to get enough oil to wrist pins etc. This makes me wonder why a CDR is used at all
Click to expand...

I was always led to believe it was to keep a slight vacuum in the crankcase to keep oil from leaking past seals. I can see how that might be bad if you were fording deep streams.
 
The purpose of the egr is emissions controls based. Rather than vent to the atmosphere, they want oil burned off so less hydrocarbons are released. But the problem is at high rpm, especially with a worn engine, it will burn a ton of the oil pushing way past amount allowed by epa levels. So the cdr limits the amount of oil vapors that can be burned.

Throughout europe devises like the provent are used because their emissions standards are higher than most of the US.
 
Will L. said:
The purpose of the egr is emissions controls based. Rather than vent to the atmosphere, they want oil burned off so less hydrocarbons are released. But the problem is at high rpm, especially with a worn engine, it will burn a ton of the oil pushing way past amount allowed by epa levels. So the cdr limits the amount of oil vapors that can be burned.

Throughout europe devises like the provent are used because their emissions standards are higher than most of the US.
Click to expand...
I think you mean CDR as the EGR is there to cool the combustion chamber, reduce cylinder pressure, and thereby reduce NOX emissions.
 
I've already proved that the stock setup never closes to limit the vacuum. So maybe they put it on there to keep the EPA off their back.
 
ak diesel driver said:
http://www.thetruckstop.us/forum/threads/my-cdr-experiment.27991/
Click to expand...
I forgot about this experiment you did. That was a really cool bit of testing you did there. I was also under the impression that the CDR closed at higher vacuum so you couldn't put too much vacuum on the engine. I was thinking at higher vacuum you could suck oil out of the engine, but now that I'm thinking about it, that's a dumb thought. I have oil on the front of my turbo even though I have the CDR and BowtieButler's oil catch can setup. @Will L. if/when you do the Provent, please post up the results, I would sure like to stop sucking oil through the engine. Of course oil is fuel....so maybe my horsepower would drop if it wasn't eating crankcase oil??? ;)
 
I will post it when If and when I can ever tear into my hummer- so aggravated that everything else in the workd keeps stopping me.

I am not sure if Bobbie Martin did a write up on it or not. I bought his old one from his suburban.

Only thing that concearned me was I seem to remember that Bison put one on one of his 6.5 rigs, and later removed it for some reason. Maybe because his "passion" for the epa /emissions stuff is greater than mine, and just vent to piss them off. Haha-

Anyone heard anything about him? Last I remember he was thinking about selling off his bison herd and I never saw anymore posts.
 
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