Crank case ventilation

[Scrymerr]

I want to ensure that my crankcase has plenty of ventilation. I want to eliminate the PCV valve, and run two -6AN lines from the two ports on the valve cover to a vented/filtered type of catch can (like RREs) instead of the recirculated type like the greddy (which would force me to either run one -10AN line (which is out of the question) or just run one -6AN line and then recirculate the other line off the catch can. My questions are: does anyone have any insight on crankcase ventilation, pictures and discription of their custom setup, or know where I can buy a vented type of catch can with two ports on it that will allow me to run two -6AN lines to it. Please do not tell me that the stock setup will do, or to use rubber lines. I have made up my mind as far as what I want to do and why, just need some help getting there.

Thanks in advance,

Dan

 

[dsm-onster]

I want to ensure that my crankcase has plenty of ventilation. I want to eliminate the PCV valve, and run two -6AN lines from the two ports on the valve cover to a vented/filtered type of catch can (like RREs) instead of the recirculated type like the greddy (which would force me to either run one -10AN line (which is out of the question) or just run one -6AN line and then recirculate the other line off the catch can. My questions are: does anyone have any insight on crankcase ventilation, pictures and discription of their custom setup, or know where I can buy a vented type of catch can with two ports on it that will allow me to run two -6AN lines to it. Please do not tell me that the stock setup will do, or to use rubber lines. I have made up my mind as far as what I want to do and why, just need some help getting there.

Thanks in advance,

Dan

I drilled out my pcv valve and cut my metal line to the other port and coupled them togheter into a plasit pepsi bottle. and tucked it down low near the fire wall. It's trashy, but no one sees it. A word of caution: both ports anre neccesary. I plugged one port and left the other one open in the catch bottle, and got blow by...

 

[Enraged78]

I want to ensure that my crankcase has plenty of ventilation. I want to eliminate the PCV valve, and run two -6AN lines from the two ports on the valve cover to a vented/filtered type of catch can (like RREs) instead of the recirculated type like the greddy (which would force me to either run one -10AN line (which is out of the question) or just run one -6AN line and then recirculate the other line off the catch can. My questions are: does anyone have any insight on crankcase ventilation, pictures and discription of their custom setup, or know where I can buy a vented type of catch can with two ports on it that will allow me to run two -6AN lines to it. Please do not tell me that the stock setup will do, or to use rubber lines. I have made up my mind as far as what I want to do and why, just need some help getting there.

Thanks in advance,

Dan

I would run a non-vented catch can instead. After working with DSMLink for a while, I found my valve cover breather was actually messing with my fuel trims. The DSMLink folks suggested I go back to a closed loop setup. This is because under vacuum, the engine will pull unmetered air from the filter on the catchcan, and under boost, metered air is lost to the atmosphere. Even though you've got both lines routed properly with the RRE kit, the filter is still pulling and pushing air depending on what the engine is doing. The computer is unaware of this, and adds or subtracts fuel to compensate. Under WOT, you will always run richer than you think you really are. Go with a sealed catch can, or build one yourself.

Matt.

 

[dsm-onster]

I would run a non-vented catch can instead. After working with DSMLink for a while, I found my valve cover breather was actually messing with my fuel trims. The DSMLink folks suggested I go back to a closed loop setup. This is because under vacuum, the engine will pull unmetered air from the filter on the catchcan, and under boost, metered air is lost to the atmosphere. Even though you've got both lines routed properly with the RRE kit, the filter is still pulling and pushing air depending on what the engine is doing. The computer is unaware of this, and adds or subtracts fuel to compensate. Under WOT, you will always run richer than you think you really are. Go with a sealed catch can, or build one yourself.

Matt.

Hmmm, i have dsmlink and never noticed this. My fuel trims are normal without taking this into consideration. You know, significant blowby, and/or soft, wore out rings usually will cause you to lose air under boost. and in vacuum. Have you done a compression test?

 

[Enraged78]

Hmmm, i have dsmlink and never noticed this. My fuel trims are normal without taking this into consideration. You know, significant blowby, and/or soft, wore out rings usually will cause you to lose air under boost. and in vacuum. Have you done a compression test?

This was on a brand new forged 7-bolt with 8.5 to 1 Ross pistons. Compression was perfect across the board, leakdown test showed less than 2% loss on all four. My rings are a little on the "loose" side, but nothing out of spec at all. We gapped the rings for a little over 500 HP, using the Ross formula. My vacuum is usually around -22" Mercury, and dips to 20" when A/C, lights, and stereo are all kicking hard.

Going from a vented filter to a routed catch can got my low LTFT and mid LTFT a little closer together. Nothing huge, but anything that will help a DSM run less than pig rich is a good thing.

Also, I made a catch can out of a Jiffy peanut butter jar. I have two 90 degree fittings on the top of it, and it's sealed with RTV to make it air tight. Using this, I can now monitor exactly how much blow-by I'm getting by monitoring the water/oil mix in the jar. So far, it's very little, so I know that I don't have a blow-by problem. I got the idea from another member on this board, and it only cost me $5.00 in parts.

Matt.

 

[Drifter27_04]

I am doing the same thing as "Scrymerr" taking and getting rid of the PCV valve.

I thought of purchasing a nice oil catch can off ebay and than eliminate (blocking) the inlet to the intake from the PCV valve tube as RRE instructions are and running both of the outlets of the valve cover to the catch can. If sounds like a great idea please let me know and if not explain why and give me all the suggestions you have. I am looking to buy a catch can tonight , tomorrow or Wednesday so I can install it on the car by this weekend.

Please if some of you guys can supply pics of the setup and mount options that would be greatly helpful.

T

 

[Scrymerr]

Well, I found a vented catch can I like from JM fab, it looks really awesome and the price is right. I will also be running -8AN lines for my setup.

However, running a non-vented catch can, I must sacrifice half the flow, and must route something back into the intake, which I won't be running. Thanks a lot for the heads up, however I am hoping with my stock cast pistons it won't be a problem.

And check this out: http://www.jmfabrications.com/universal.html

I will be getting the deluxe one.

Dan