not running a PCV valve

[karolko]

So here is my question, why don't people remove the pcv valve in their engines?

From my understanding if you have a pcv valve setup, you are allowing oil vapors to enter into the engine, and be burnt up. this is all fine and dandy IF you care about emissions BUT if you introduce oil vapors into the charged air, you are effectively dampening your octane count, thus increasing you likelyness for detonation.

On one of my first custom turbo builds on a honda ( i know, i know) i took the PCV system completely out and ran and oil catch can setup to trap oil vapors. the catch can, collected any oil vapors in the can, which could of been emptied out if it got full (but it never did).

So why incorporate this into our buicks.


Any comments, or people who have done this? Photos

[87Regal3.8SFI]

First I have heard of this, but what would happen if the engine didn't have a PCV? Would it still be able to scavenge the blow by from the block?

[karolko]

correct me if i am wrong, but the PCV works when the car is in vacume, and during this time, it is sucking out the vapors being created in the crankcase from the roating assembly. Now under boost, the system is not puching in oil vapors, however, oil is being deposited onto the intake walls when the car isn't in boost, which COULD be picked up by the charge system during boost.

Maybe i am oversimplifying this, but if you have filters on your valve covers and have no pcv valve, you just have an open system, where oil vapors can vent into the atmosphere as they please.

Am i retarded, or could i be onto something?

[SNOWBIRD]

Some of the blow by and water vapor would be eliminated by your breathers in the valve covers,,,a street driven car should have a pcv system and if it is sucking oil ,put a GOOD catch can in in the system ,,,my modest opinion

[SNOWBIRD]

O,,,put a check valve in the hose so the catch can will not fill up with boost.

[karolko]

check valve??? why would you do that? if you had a breather on the catch can, then you should be fine. Plus how much boost actually seeps past the rings?

[SNOWBIRD]

Let me rephrase that ....a air oil separator not a catch can

[karolko]

could you explain or post a link to what the difference is?? I'm curious.

Thanks

[PaCemkr86]

<--- NO pcv valve.. Just 2 full size breathers... and no oil leaks..

[87Regal3.8SFI]

Hhhmm....now you've really got me wondering if oil vapors in the charged air really do have an impact on knock.

[bison]

I havent run PCV in nearly 10 years. It does nothing to help with performance and is not needed. Id leave it on a nearly stock car that i planned on driving thousands of miles between oil changes but its not needed otherwise. 2 breathers and block that PCV. For guys making a lot of passes and pounding the car hard at 20+psi the oil should be changed every couple weeks or even more. No need to worry about moisture and other contaminants if your changing the oil frequently. No need to worry about an oily mess in the intake. Most dont seal for crap anyway and leak boost into the crankcase when under power . That cant be good. Catch cans/seperators are a waste of money, ugly, and a plumbing nightmare.

[PaCemkr86]

I agree with Bison 100%

[REAPER231]

i took bison's advice and blocked it off , run two breathers runs fine , problem solved

[Boost231]

Originally Posted by bison

I havent run PCV in nearly 10 years. It does nothing to help with performance and is not needed. Id leave it on a nearly stock car that i planned on driving thousands of miles between oil changes but its not needed otherwise. 2 breathers and block that PCV. For guys making a lot of passes and pounding the car hard at 20+psi the oil should be changed every couple weeks or even more. No need to worry about moisture and other contaminants if your changing the oil frequently. No need to worry about an oily mess in the intake. Most dont seal for crap anyway and leak boost into the crankcase when under power . That cant be good. Catch cans/seperators are a waste of money, ugly, and a plumbing nightmare.

+1

[karolko]

thanks for the input guys,

what do you use to block off the pcv hole in the intake? do you tao a hole and run in an aluminum bung???

and if you are storing the engine for a long time, couldn't you just take out the breathers, and run some sort of plug to prevent oisture from entering the engine bay?

[TurboBuRick]

Not a good idea to plug the pcv. The noxious fumes will come into the cab and slowly asphyxiate you. Not to mention your oil will become contaminated much faster than normal.

Not a big deal on a racer but no good for driver.

[karolko]

i do not undertand how th oil will become contaminated faster. care to explain.

[REAPER231]

i didnt block off the intake , blocked off the vacuum block at the top , kept everything in place ,

[TurboBuRick]

Originally Posted by karolko

i do not undertand how th oil will become contaminated faster. care to explain.

The PCV valve is very important in our engines. The gasses and moisture are not evacuated when a PCV valve is not used. This will cause a tremendous amount of moisture sludge in a motor contaminating the oil.

[TURBOPOWERED68]

I have the PCV valve hooked up
And I still have the pipe to the inlet bell from the right side valve cover hooked up.
No oil leaks here.
I would sacrifice a little power just not to have an oil leak
Plus wouldn't the ALKY wash the intake out as you use it??