PCV Oil Catch Can

[Tristan Smith]

Need some opinions. On the new ITR 300zx I am building I need put in a catch can for oil. Evidently the stock PCV design is bad and has the tendency to dump a lot of oil into the plenums, especially when raced or run hard.

So My question is:

Should I just vent the crankcase lines (there are two on the zx) into an open catch can and plug up the PCV valves?
And is there really going to be an issue with having an open line like that? Some opinions are that you are creating a "intake leak" by not keeping it a closed system.

Or do I need to keep the system as is, and add an oil separation can and keep the PVC valves as is.

Personally I never had any issue running the system open in the 240sx, and would like to keep the oil from having any route back into the intakes.

Thanks.

[Ron Earp]

Tristan, I'd run them to a can. My Lightning truck also has a problem of putting oil into the intake, blower, and intercooler and over the years it causes a decrease in performance. One solution, as you've mentioned, is an oil separator in the PVC system.

However, this is a race car and the PVC system is purely an emissions device. You are allowed to remove it. Plug the intake side of the PVC system and run the crankcase/valve cover lines over to a can. You won't have an intake leak that way and you'll be running the same system that pretty much every other IT car does.

FWIW the 260Z had a PVC system but no longer. Intake holes plugged and lines run from the crankcase/valve cover to the catch can.

[JeffYoung]

Ditto. On the new FI motor on the TR8, I plugged all that stuff up and run two lines, one from each valve cover, to a catch can. Works fine and no intake leak if you block everyything on the manifold off securely. No issues on my car (so far).

Ron, you at the house? I've tried calling a couple of times to see if you were around.

Jeff


Tristan, I'd run them to a can. My Lightning truck also has a problem of putting oil into the intake, blower, and intercooler and over the years it causes a decrease in performance. One solution, as you've mentioned, is an oil separator in the PVC system.

However, this is a race car and the PVC system is purely an emissions device. You are allowed to remove it. Plug the intake side of the PVC system and run the crankcase/valve cover lines over to a can. You won't have an intake leak that way and you'll be running the same system that pretty much every other IT car does.

FWIW the 260Z had a PVC system but no longer. Intake holes plugged and lines run from the crankcase/valve cover to the catch can.

[Tristan Smith]

Thanks guys. Merry Christmas!

[timo944]

Tristan,

Look in to one of these: http://www.saikoumichi.com/product_line.html

This keeps vacuum on the crank case while storing the oil. With the 944, venting to atmosphere has been a problem, causing the engine front seals to leak. There are a few 944/951 guys that swear by them.

I don't have one yet but an getting ready to buy one.

Hope all is well

Tim