Oil Catch Can Dimensions

[HumbleGhost]

I purchased an OCC off of Amazon and the fitting for the in and out lines are 6mm or 10mm so I bought some 3/8 inch fuel line to run the setup as recommended by other buyers.

So I plan to use a piece of the OEM pipe from the PCV valve into a reducer to the 3/8 inch hose to the occ, then out with 3/8 inch hose to a 1/2 inch check valve, out to a 90 degree elbow that turns back to 5/8 inch for another segment of the oem hose to the IM.

My question is, will there be a problem running the OCC on primarily 3/8 inch hose?

In other words, will this be too restrictive or will the pressure that is normally flowing under vacuum do fine in the 3/8 inch tubing? I obviously want to avoid having too much gunk build up in the tubing going TO the OCC, and now I am just paranoid that my setup might be too restrictive.

Thoughts are appreciated! I already bought 20-30 bucks worth of tubing and tube connections.

[wowndup]

I'm a new member and that being said, here goes: auto and truck power steering systems have used 3/8" return line for years. I guess this OCC setup is of a gravity feed type? Even if it's suction, the PSI will likely be low. You could maybe attach a hand held vac. pump and squeeze it to 3-6 PSI and see what happens. Just a thought.

[HumbleGhost]

Originally Posted by wowndup I'm a new member and that being said, here goes: auto and truck power steering systems have used 3/8" return line for years. I guess this OCC setup is of a gravity feed type? Even if it's suction, the PSI will likely be low. You could maybe attach a hand held vac. pump and squeeze it to 3-6 PSI and see what happens. Just a thought.

It's not gravity feed although the slope/orientation of the tubing from the PCV to the OCC should be considered to prevent pooling. During non-boost conditions the line will have vacuum pulling excess crank pressure through the PCV valve to the catch can and into the intake manifold. During boost conditions, the check valve I will install will prevent boost from leaving the intake manifold and traveling to the catch can.

My concern is that the OEM hose was 5/8 ID and I am reducing that to 3/8 for the length of the setup. Some of the sludge/oil/vapors that I have seen come out of the PCV is pretty nasty, so I wanted to be sure that having a smaller diameter tube wouldn't cause it to gunk up too fast or at all. I do plan on orienting it so that the hose runs more or less downwards towards the OCC (at least not upwards) so that gravity will help it out.

At this point, I think I will just install it like I had planned and monitor it for a while....I just don't want to ignore something they have probably engineered for a reason, unless its no big deal.

[kTaLgsTo]

The most important thing is to have the can at the lowest point.
That way when the car turns off it all settles to the can. This is especially important in freezing climates.

[tegxsi]

All OCC kits use 5/8"
I would think if you are not letting your crankcase pressures relieve itself efficiently through the PCV then it's going to go elsewhere.
May also lead to excess fuel dilution.

[Solarsurge]

Reductions in your hoses will cause back pressure and make it harder to flow through. I would keep it equal diameter to prevent it from getting clogged.

[HumbleGhost]

Originally Posted by tegxsi All OCC kits use 5/8" I would think if you are not letting your crankcase pressures relieve itself efficiently through the PCV then it's going to go elsewhere. May also lead to excess fuel dilution.

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

This is the catch can that I bought. The threads for the barbs are metric M16*1.5 and I can't find one that converts to a 5/8" hose barb, only 1/2" which is closer to OEM than the 3/8 inch I had planned but still not the same.

Any ideas?