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Oil catch can for Crankcase ventilation tubes?

I run one I got off ebay and it works well no more oil in the air filter or in the engine compartment. It takes a few months before I need to drain it. I'm happy with it.
OCT_0901_A2K.jpg
 
IdahoEagle said:
Isn't that what a PCV valve is for??

Well...

I know my '88 never had a pcv valve...

it has a CCV grommet...

not sure about the newer ones but IIRC they're the same deal...

I tried to use a pcv valve once...

and proceeded to blow out my rear main seal!
 
In theory the ccv should do that but older engines have blow by. I took the valve cover off removed the valves and replaced them with a pvc valve that runs to the manifold and the other one that is just a vent runs to the catch can. I have no more blow by and no more oil all over my engine compartment.
 
IdahoEagle said:
Isn't that what a PCV valve is for??

PCV valves are usually used on forced induction engines. When these engines are under boost, the air pressure inside the intake manifold is greater than the pressure inside the crankcase. The valve prevents gases from being blown from the manifold into the crankcase, otherwise oil seals on the engine would leak. Since it's a one-way valve, it does allow gases to go from the crankcase to the manifold when the manifold is under vacuum.
Naturally-aspirated engines don't need a PCV, hence the CCV system that uses intake manifold vacuum to scavenge crankcase gases. Fresh air has to enter the crankcase to prevent it from developing too much vacuum, and that's why it draws filtered air through the front grommet.
 
Dr. Dyno said:
Naturally-aspirated engines don't need a PCV, hence the CCV system that uses intake manifold vacuum to scavenge crankcase gases. Fresh air has to enter the crankcase to prevent it from developing too much vacuum, and that's why it draws filtered air through the front grommet.

Now I assume you know what your talking about, but then why on some NA engines (as most do have a PCV) when the PCV sticks open (constantly allowing the crank case vapor into the intake) will it set a code?
 
On my turbo car it is a normal cheap fix to just run a cheapy homo depot air separator and remove the goldish colored stone filter from it. It fills up about month and it just gets drained in to a rag by me when I see that its getting full.As for only older motors being that bad on blow-by. I have to disagree. My brand new motor (given the rings may have not seated fully yet) has a crap load of blow-by...

PS the only reason we run a 'catch can" on our turbo cars is that if we dont the oil will accumilate in the up pipe from the intercooler and gum up a very expensive front mount intercooler at somepoint as well as causing a small amount of fluctuation in the ECU from a oil mix in the freash air.
 
CW said:
I run one I got off ebay and it works well no more oil in the air filter or in the engine compartment. It takes a few months before I need to drain it. I'm happy with it.
OCT_0901_A2K.jpg

Good looking setup there. What do you think of hte build quality?

I must admit that I feel dirty looking at stuff targeted to ricers for my Jeeps :D
 
GSequoia said:
Good looking setup there. What do you think of hte build quality?

I must admit that I feel dirty looking at stuff targeted to ricers for my Jeeps :D

I was that way but I couldn't bring myself to put tin can under the hood of my expensive stroker either. The fill level tube makes it easy to know when it needs to be emptied. Finding a place to mount it is a pain though, It fits pretty good next to the hood latch on the drivers side, but I have to take it off the mounting bracket to drain it.
Summit makes one with a breether on top that would work decent. SUM-G1506 $29.99
 
this is another big seller for the arena I am in with the turbo's and all...

weaponr_oilcatchtank_LRG.jpg


if that interest ya its only 59$ lol
 
Thanks for the responses ... those aftermarket units look nice and pretty, but I think the can would work just as well.

I'm going to go ahead and make mine, and try to add the side clear tubing as a "gauge" to let me know when to drain it.

I also might use a ball valve on the bottom to make it easier to drain. Just reach down, turn the lever with your hand to drain the oil into another can or something.

Also ... looking at the DYI instructions, I think the stiff putty-type of epoxy would be good for installing the pipes. You can buy it as "gas tank repair" putty. I used it on a gas tank when I was 16 and had a '67 VW Beetle, and it worked great. Dried solid, but not brittle like JB Weld.
 
chris1044 said:
Now I assume you know what your talking about, but then why on some NA engines (as most do have a PCV) when the PCV sticks open (constantly allowing the crank case vapor into the intake) will it set a code?

I can only guess that this is the case on newer computer-controlled engines that have to meet much tighter emissions regs. If oil vapors are allowed to enter the intake manifold unhindered, they'll increase the hydrocarbon emissions unless all the oil vapor is burnt in the cylinders.
The HC emissions from my stroker were only 36ppm at the last vehicle inspection. I don't know if the catch can made the difference though 'cause I didn't have the emissions check on the stroker before I installed it. I CAN tell you that my old 4.0 put out 120ppm of HC and it was in an excellent state of tune with negligible oil consumption.
I checked my catch can after six months of use and there was only a tiny amount of oil in it (the catch can that montanaman referred to in his first post is mine).
 
Dr. Dyno said:
PCV valves are usually used on forced induction engines. When these engines are under boost, the air pressure inside the intake manifold is greater than the pressure inside the crankcase. The valve prevents gases from being blown from the manifold into the crankcase, otherwise oil seals on the engine would leak. Since it's a one-way valve, it does allow gases to go from the crankcase to the manifold when the manifold is under vacuum.
Naturally-aspirated engines don't need a PCV, hence the CCV system that uses intake manifold vacuum to scavenge crankcase gases. Fresh air has to enter the crankcase to prevent it from developing too much vacuum, and that's why it draws filtered air through the front grommet.

Pre mid 60s auto engines, and other emissions exempt engines vent crank case gasses direct to the air via a down tube.
PVC valves have been used in American automobile engines since the Feds mandated venting the crankcase fumes somewhere besides the open air. The PCV valve allows for a one way flow from the crank case to the manifold regardless of induction style. It also meters the amount of vacuum at the crank case. The other side of the system is a breather to let air in to the crank case. The PVC valveless system used in the Jeeps and other vehicles now is a cost reduction effort. I first saw this on a 74' Renault. Just a fixed size orfice stuck in a hose between the crank case and the manifold to reduce the amount of vacuum provided to the crank case. Only bad thing about this new system is finding out where the orfice is to unplug it. The PCV valve was a no-brainer since every car had one in about the same place and you cleaned it when you changed oil and cleaned/regapped your plugs.
,Ron
 
Dr. Dyno said:
I can only guess that this is the case on newer computer-controlled engines that have to meet much tighter emissions regs. If oil vapors are allowed to enter the intake manifold unhindered, they'll increase the hydrocarbon emissions unless all the oil vapor is burnt in the cylinders.
The HC emissions from my stroker were only 36ppm at the last vehicle inspection. I don't know if the catch can made the difference though 'cause I didn't have the emissions check on the stroker before I installed it. I CAN tell you that my old 4.0 put out 120ppm of HC and it was in an excellent state of tune with negligible oil consumption.
I checked my catch can after six months of use and there was only a tiny amount of oil in it (the catch can that montanaman referred to in his first post is mine).

That is the answer, just wanted to see if you knew (as your name is Dr. Dyno....). Most everything now has a pcv for emissions reasons....
 
Another reason for a working PCV/CCV system is to help rid the crankcase of combustion byproducts and water vapor...without it there is a very good chance of sludge build-up in the engine....goes hand in hand with a proper engine temperature.
 
Dr. Dyno said:
I checked my catch can after six months of use and there was only a tiny amount of oil in it (the catch can that montanaman referred to in his first post is mine).

Dr. Dyno ... thanks for the response. Love your website, and it's great to read your knowledgeable posts.

Do you think the catch can is worth it? I mean ... if it only catches a tiny amount of oil in 6 months, what's the benefit? CW said he needs to drain his every few months.

What might explain the difference between your jeep and CW's? Could that indicate your motor isn't misting much oil under the valve cover? Or could it indicate the catch can isn't catching all of the oil? Maybe your motor is newer with less blowby? Whaddaya think?
 
montanaman said:
Dr. Dyno ... thanks for the response. Love your website, and it's great to read your knowledgeable posts.

Do you think the catch can is worth it? I mean ... if it only catches a tiny amount of oil in 6 months, what's the benefit? CW said he needs to drain his every few months.

What might explain the difference between your jeep and CW's? Could that indicate your motor isn't misting much oil under the valve cover? Or could it indicate the catch can isn't catching all of the oil? Maybe your motor is newer with less blowby? Whaddaya think?
Dr. Dyno's motor is a rebuilt stroker, I think he's got like 20K on it. I'm sure he'll chime in.
A well used 4.0 with worn rings will certainly have more blowby, as more combustion chamber gasses seep by the worn rings you build more pressure in the crankcase, and expel more oil up through the top end of the motor. That's my understanding anyway, I've been wrong.
 
I have to empty mine every 3-4 months on a stock 4.0L that has some major issues due to the previous owner having an engine built by a retarded shade tree mechanic who I'm pretty sure didn't own a torque wrench. On my stroker after 2 months I am yet to read anything on the fill tube. I only put one on the stroker becuase I had a tiny amount of oil on my valve cover from when I was just running a breather filter.
 
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