I deleted my PCV 2-3 yrs ago...just run a check valve. No idle issues, maybe I got lucky.

 

Ok this makes more sense. I will see about placing the check valve inline in front of the pcv. Both will be on the manifold side of the can on the same 3/8 line as my lines to the VC are already -10 and the manifold stayed 3/8.

 

Ok so i have read this entire thread atleast three times as well as just about any other thread on this topic. At this point, I feel my objective is quixotic and I may have better spent my time on a unicorn safari.

Mr Fred, I would truly appreciate a sanity check from you if you dont mind. Here are my objectives/requirements:

1. Single catch can between PCV and intake
2. Mishimoto baffled catch can (non-VTA)
3. Retain original PCV (added check valve between intake mani and catch can to prevent pressurizing)
4. Maintain stealth/stock look (read no frickin chrome or other colors aside from red and black)

In summary where I am stuck is trying to step down from the M20 x 1.5 ports on the can down to 5/16. So far i have spent about $200 just for fittings to go from metric thread to imperial (because noone makes a metric thread coupler that goes from that thread size/pitch down to -6an ) and $150 of that was to strip the blue annodize and annodize in black. -6an wont even cut it as -5an=5/16 and hell if I can even find a coupler to get to 5/16 without an Eiffel Tower coming out of the can.

I know I can use -10an if I do a press in fitting but I'd prefer not to go this route if I can help it.....unless of course unicorns are out of season. Assuming they aren't out of season i will try these next. http://www.chicompany.net/index.php?...roducts_id=417

Here are pics of it so far:

 

It looks like it will take care of keeping oil out of the intake manifold, but what you've mentioned here won't help relieve crankcase pressure. I've come to the realization that the simplest method to attain this is to bite the bullet, remove the valve cover, have it drilled and tapped for 3/8" NPT in the location of the stock breather, and then run 1/2" hose or 5/8" hose (from a fitting at the 3/8" NPT tap) either VTA or to the intake pipe.

One thought I have on a catch can for the PCV line is that its good to make it easily accessible because they need to be drained often.

 

What about running the can direcrly into the dipstick? Thats what im doing. One can from my hals cap to the can with a drain to the dipstick. Then both vc fittings and block vent to a seperate can.

 

It's these nuggets that one digs through 61 pages for. It's also funny to see how we all go in a big circle to end up just about back with what the factory did.

 

Yep, factory works fine. Just a tad too small for the rest of us

 

Yeah, being able to measure crankcase pressure made me much more confident in this solution. Just a quick thought that I should have mentioned before - anyone who decides to run the line to the intake should have an appropriate size fitting for the hose on that end. Its kinda implied, but might as well be totally explicit.

 

During your testing did you get a reading for the amount of crank case pressure for different size lines that run to the intake or just one test with a bigger line?

 

I've got measurements on various setups dispersed throughout this thread. Quick summary for my built motor is (all values are peak and occurred at WOT max RPM):

Completely stock: ~2.7 psi (IIRC) out the the top.

Stock breather with 3/8" hose and fittings (approx -6 AN) VTA on the PCV side: ~0.75 psi.

1/2" hose and fitting VTA on breather with PCV side plugged: ~0.2 psi.

I figure that 5/8" hose and fittings VTA should be good for ≤0.1 psi, and 1/2" or 5/8" with a good siphon attachment to the intake pipe might pull a slight vacuum, at least for my motor.

 

You sir are the man! Thank you.

 

we have a new billet machined adapter for the block that we will be releasing shortly- to add a -12 in a creative way to the case itself

the issue we've seen in road race cars (on various configurations) is even with a Kiggly etc the oil simply cant return to the pan fast (easy) enough since there is no "true" crank case vent on the motor- its just a vented valve cover- and the oil is sharing its return orifices from the head back to the pan while there is pressure doing the opposite-

cb

 

That's a good point about the oil being unable to easily return. Would love to have a -12 AN on the crankcase if it bolts on and doesn't spit out too much oil.

 

Just a quick question...
In case of a valve cover that has no baffles inside, is there something to put inside the hose to prevent filling the catch can with oil...

Splash screen or oil trap I've seen it somewhere...blocks the oil and thus keeping it inside the valve cover..

 

Steel wool