Thread: eliminating the pcv?

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at insane rpm's then letting completely off the throttle oil will blow out of the rubber grommet around my pcv. never had this happen until the rebuild got me way more hp than previously. Do notice on cruise nights some have no pcv, just a breather on each valve cover. Opinions please?

What are you doing on the other side; are you running a breather (open) or is it connected to the air cleaner (closed).

PCV will help knock down odor, improve emissions, and keep positive pressure from causing oil leaks. If you are blowing out oil your baffle is not working up to snuff on the PCV. Sometimes this may require some enginuity to solve. Bottom line I would not run without a PCV.

Kitz

no air cleaner routing involved, I have the fabricated aluminum tall covers and had to drill both openings. Air cleaner is chromed type with fully exposed K&N element. No baffle or shield on the pcv side either, just the rubber grommet and pcv shoved in it. Friends have commented I'm sucking oil out of the valve cover at all times, then when no vacuum is present it would blow past. Such as in WOT.

you just need to put a baffle in of some sort on the inside.. if you can't weld aluminum, you could use a good 2 part epoxy putty

Originally Posted by Matt167

you just need to put a baffle in of some sort on the inside.. if you can't weld aluminum, you could use a good 2 part epoxy putty

Where does the good, 2 part exopy end up when it comes loose?

Hopefully you drilled the hole between rockers. Then Moroso I believe makes a long grommet with a slotted bottom that they call a baffled grommet. I bought one from Summit. See if that helps. From there you can put some mesh screen or something in that baffle to aid further if needed. You can increase the height at the PCV using a riser etc. Or you can make a baffle and add it to the inside if all else fails.

Kitz

Originally Posted by 42K3

Where does the good, 2 part exopy end up when it comes loose?

providing the valve cover was properly cleaned inside before it was applied.. it never will come loose. I use quick-steel for stuff like this all the time, never been a problem.

Originally Posted by kitz

What are you doing on the other side; are you running a breather (open) or is it connected to the air cleaner (closed).

PCV will help knock down odor, improve emissions, and keep positive pressure from causing oil leaks. If you are blowing out oil your baffle is not working up to snuff on the PCV. Sometimes this may require some enginuity to solve. Bottom line I would not run without a PCV.

Kitz

Kitz, when I was setting up the 34,our local Speed Shop said it was OK to run the two breathers on the valve covers and the PCV valve was not really needed.What do you mean by positive pressure causing oil leaks.Where would you notice an oil leak? Should I re-do the system? Thanks

You will get blow-by causing positive crankcase pressure unless you relieve it some how, no breathers or PCV valve.... oil leaks. Breathers on each valve cover will do, however if the breathers do not catch vapors you will end up with an oily film on the valve covers. The PCV valve captures these vapors and routes them back into the combustion chambers. What you put on the other side will make the system either open or closed. Breather = open, line to the air cleaner = closed. Either will work I like a closed system

Originally Posted by Don Dalton

Kitz, when I was setting up the 34,our local Speed Shop said it was OK to run the two breathers on the valve covers and the PCV valve was not really needed.What do you mean by positive pressure causing oil leaks.Where would you notice an oil leak? Should I re-do the system? Thanks

Sorry for the delay.

If all you use is breathers (and I have done that) there wil be a net positive presure inside particularly under heavy throttle useage. It will not be severe, perhaps ~1-2 psig or so. Why? Breathers do have some restriction and at heavy throttle there is more blow by to contend with.

Will this lead to a real leaking problem? I think eventually it will, but a lot of that depends on how well sealed the motor is and what your driving habbits are. I just never liked them because of the stink I always seemed to notice versus using a PCV. Also make sure the breathers in all applications do not get clogged or the pressure will go up quickly.

Kitz