Quick catch can/breather ?

[Underrated99si]

First off I know it's been covered a million times but the info out there is so All over the place.

Like all Type R's I burn a small amount of oil at the track. It's minimal but I want to make sure it isn't running back threw intake.

Not looking to delete all the pcv system but simply tap in 1 or 2 AN fittings to valve cover and run to a catch can and leave pcv system still in place.

Anyone run this set up? I figure the crank case pressured should follow the path of least resistance and factory small pcv system will never get over tasked.

I'm thinking this set up cause of all the issues I read about oil drain back issues puking or vacume issues.

Thanks for reading and for any feedback

Chris

[neatrip]

This is a question I hope someone can finally be able to share some thoughts about if there are any actual benefits or even disadvantages when using a tapped VC for crankcase ventilation in combo with the preexisting pcv system.

I have wondered the same for some time but most of the information I've found usually involved such systems for F.I. treatments or deleting the whole PVC/blackbox by plug and exclusively relying on catch can/breather.

I can see where OP gets his reasoning when he mentions hopes to relieve the factory pvc system if VC was tapped and fitted to a can/breather kit.

But does it actually make sense from a real technical standpoint?

I'd also like to hear some thoughts...

[3pedalJohn]

I will post my thoughts on the topic because I have been experimenting with crankcase breathing. I have a fresh 84mm B18C1 with ITR cams and stockish compression ratio of 10.6:1 . I used the back of the block ports and experience a ton of oil fill up in my catch can, plugged the driver side hole and ran the block plug above the black box hole and the also caused the catch can to fill up. I have since switch to valve cover venting only and haven't experienced any oil filling only the vapors condensing in the can and my motor isn't sucking down oil like my old motor was with the stock PCV system. I was checking other NA B series at Road America this past week for crankcase breathers and most vented from the valve cover by various methods.

When running at high speeds on the track you will have little vacuum in the intake manifold so your PCV system won't be pulling much crankcase vapor through the PCV system, most of it will go through the vent in the valve cover into the intake tube. By running the PCV system you will still pull crankcase vapors, when cruising around since you will have vacuum in the intake, the flow will be in conjunction with the spring the the PCV valve.

I removed the black box and run a tube of the stock vent on the valve cover to a catch can and got maybe 3-4oz of oil to condense in my catch can from roughly 180 track miles at Road America this past week.

[coolhandluke]

I haven't personally experienced issues venting from the block, but I know many who have. I agree with the previous comments that venting from the Valve Cover is the better approach. King Motorsports and others offer services to (properly) modify valve covers. I personally have a Moroso catch can I purchased used, but the catch can is the simple aspect of the setup. A vent from the valve cover with splash shield should reduce the risk of overflow issues.

[neatrip]

The information is appreciated.

I've run through information where mostly the factory black box is done away with/blocked when the valve cover is vented (usually into a vented catch can with a breather filter on top of it).

In some cases, it isn't specified if the black box has been removed but the owner may use a vented valve cover with 2 ports or barbs in front of valve cover into a catch can.

In my personal preference with preserving my engine to be close to stock condition and appearance as possible, I would like to maintain the factory PVC/blackbox but consider any possible way slightly relieve the stock system.

I was fortunate to be able to acquire a discontinued Vibrant scavenger oil cap to help me achieve this setup without modifying the valve cover.



However because I still do not fully understand crankcase dynamics, I am not sure if this will be hurting or helping considering I will retain the stock PVC system but use the scavenger oil cap to route drainage into a separate oil catch can.

Would it hurt or serve any slight function in this case to use a vented catch can (with breather filter) or would a closed (non vented) catch can be the most ideal?

Fyi, the car is a weekend cruiser and serves occassional autox duties.