transam69230

iTrader: (49)

I am getting a LS6 shortblock in a few weeks and i want to delete the pcv system out, but the searsch insn't working, and i want to know how to delete the system, i already have a breather from speedinc. I just want to get ready so when put the new block in i don't have to f**k around, and take **** apart when i get it back together.

brad8266

iTrader: (23)

Just remove the hoses, and plug up any vacuum connections that are open.

Shinobi'sZ

You know I deleted my PCV because I got tired of seeing oil in my intake...even with a catch can. I just used crank case vents on the valve covers, and a road draft tube coming off of the PCV. Then I was told that the PCV was necessary to aid in ring seal.....is it bullshit or can we do without the PCV all together?

WARP211

The PCV system is part of the emisson system.. By deleting the PCV System you will force more blow by in the crankcase.. I think by doing that you can damage the Rings in the pistion, Or your oil can sluge up..Why.?? Cuz what is blow by.. Blow-by is The gases that haven't got use up in the cylinder.. As you all know that when the combustion process happens all the exhust gases don't get burned up. Thus creating blow-by gases.. The PCV Directs these blow-by gases to get Re-burn in the intake. Also your oil will get contamined with the blow-by gases and can cause oil sulge up..

brad8266

iTrader: (23)

^^^ I would keep the PCV system, it doesnt hurt anything.

Shinobi'sZ

Not sure I agree with your answer, it doesn't appear that you read how I addressed Positive Crank Ventilation. The gasses can escape via crank case vent or a bypass tube as I described.

Blow by to me is more when the compression ring looses the ability to seal and the combustion gasses (whether FI or NA) get by the compression ring and then what you describes can happen. I am pretty sure I witnessed this when I was pushing 18+# of boost and I noticed a lot of vapor coming from my crankcase vent.......that is more likely to be positive crank pressure do to blowby.

My understanding of PCV system, is that when the crank is rotating and the pistons move up and down in the cylinder, that it creates some positive cranking pressures...this is why the windows were cut into all of the 2001+ lSx blocks (aka LS6 at the time), thus helping to relieve that pressure underneath each cylinder by allowing it to move freely throughout the bay.

The PCV system is to help pull any vapor or pressurized gasses back up into the intake to be burned...because they were not burned in the first place....it helps keep the Cats clean and from being clogged too.

So without using the broken search engine, and relying on other people's setups I will revert back to my question with a little more detail.

Do we really need PCV....without having to install a vaccuum pump?

brad8266

iTrader: (23)

You dont "need" it, but it does serve a purpose. You can pull it if you want to, I left mine on since it doesnt really get in the way.

Shinobi'sZ

No doubt that it serves a purpose...but I was trying to dig if anybody new exactly how much that purpose counters the negative effects of vapors getting back into the intake and carbonizing on top of the pistons.

When I had a forged motor built, I put the heads on and pulled the PCV..I also cleaned out the intake with Diesel and Simple Green...this was after my motor blew up with my D1 and I had oil everywhere. Later I took off my heads (to open up the chambers) and the intake and cylinders did not have any of the carbon build up and residue. I am thinking this is because there was no PCV hooked up. It was after that that somebody told me I needed the PCV for reasons other then SMOG...so I hooked everything back up...I recently pulled my motor and low and behold both the intake and tops of the pistons had oil and carbon ontop of them.

So what is the cost benefit of having the PCV? This is what I am hoping to explore out of this thread for myself and others.

Tom@SpeedInc

iTrader: (5)

I've been running iron block 402ci daily driver with no PCV for couple months; when I was running with PCV system nearly poured a pint of oil out of my intake manifold, when I removed it.

Atomized oil in the intake is nothing good, oil doesn't burn well and leads to detonation. Its a double edged sword.

After reinstalling intake manifold, installed a breather on it plugged off the crankcase ventalation ports, never looked back since.

My only reservation was, the oil may not be able to burn off all the condensation it collects. Had an oil analysis done after 1000 miles, couldn't have expected better results. 0% water 0% fuel, viscosity and wear numbers on par.

Provided you get the engine up to running temp routinely, no problem deleting PCV system. Theirs a turbo fbody race car I know of came in the shop with some nasty looking yellow oil, we all figured it lifted the heads, it was caused by condensation according to blackstone labs, race car rarely sees oil temp above 200*.

SmaknaSS

iTrader: (1)

Running breathers for 15k miles here with no problems.