Pcv or not to pcv?

[82sbshortbed]

How bout this? Never seen one.

https://privatelabelmfg.com/product...rrKN-Nj--RECjPXYxtBt8kewwj_Mq8ZfJlHsf97ux8TAY

 

[Paladin]

Dang, Now I am so confused, all the back and forth over the simplest of subjects (or so I initially thought) my ******' head hurts! Must be time for some herbal therapy!!! For what it's worth which is probably nothing I have the PCV on the pass side and a shielded breather on the drivers and ever since I installed engine have had zero problems and my engine seems to operate fine and have not seen any sludge buildup when changing oil which I do every 3000 miles. Which is a total other subject as I have learned from another thread that by using one of the super duper new oils I don't need to change it but once in a lifetime! Bah Humbug!! I'll continue to waste my money on oil changes!!!

 

[SquareRoot]

The crankshaft spins clock-wise, so a slight vacuum will be generated on the driver's side and pressure on the opposite side. If you put the PCV in the driver's side and the breather on the opposite side, you are working against that fact, so I would put the PCV on the passenger side, unless you have a diagram that shows otherwise.

Uhhhh....no. Its not that complicated. Its the movement of the pistons that create pressure in the crankcase. You don't blow gaskets on sealed engines if your creating vacuum.

 

[Swearbody]

Hell yeah guys> i am dealing with pcv issues at the moment so this is a great thread. I had a horrible howl coming from my carb i blame the pcv for,"tested confirmed".
I ran it yesterday with the pcv
"venting" to atmosphere and wound up with a ton of oil on top of the engine. Blew right out the pcv valve on wot pulls.
Does anyone know how much oil should escape the pcv when hammering on it. I know it vents vapor but ive never seen one pump oil from it. Had to be 1/8-1/4 quart, and thats just what was left on the motor. Surely that much oil doesnt get pushed into the carb/intake every wot pull? UNless I have hella blow-by on this newly built motor. I do have baffled rocker covers and using a high volume oil pump if that matters.
Also i had smoke," like rings bad", when I would WOT before unhooking the pcv from carb...now I dont; So I know a ton of oil was getting into the intake every hard pull.

 

[Swearbody]

Uhhhh....no. Its not that complicated. Its the movement of the pistons that create pressure in the crankcase. You don't blow gaskets on sealed engines if your creating vacuum.

Yeah it definitely "blows" out the driver head,LOL. From recent "today" experience.

 

[Swearbody]

Even in the pre-PCV valve days, GM knew they had to get combustion blow-by gases out of the crankcase to reduce oil contamination and pre-mature wear on bearings, cam lobes, etc. So they used a road draft tube that dropped down in the air stream to pull a vacuum on the crankcase through the breather on the oil filler tube. It only worked when the vehicle was moving, so it wasn't "positive". On vehicles with dirty oil or lots of blow-by those tubes would emit a trail of smoke. Anybody else remember those days?

As for hurting engine performance, even the highest performance engines use PCV valves. If you've ever played with one, you'll notice they are only open at moderate vacuum, and are nearly closed at idle and WOT, assuming you have the correct valve for the engine.

A pcv is fully open at WOT not closed at all. barley open=idle or deceleration, Mild throttle is half way open, and WOT is fully open. It only closes with backpressure" backfire"
Not being contradictory for fun...just know its important info to get right. If a pcv closed at wot it wouldnt be doing its job and you would be blowing seals and pushing oil into places it doesnt belong.

 

[Ricko1966]

Swearbody pcv is not your problem. Your fresh motor needs to be disassembled and examined closely.1st thoughts rings upside down or wrong size.2nd thought they reused pistons with damaged ringlands or didn't clean the ringlands.But if you are correct and really blowing that much oil out, you've got a bigger problem than crancase ventilation.

 

[Rusty Nail]

Too bad there isnt an expert here that can explain it all away.


Edelbrock "elite series" valve covers by chance? @Swearbody I threw a pair away because they dont have baffles in them.
A Sphincter says what?

xc_hide_links_from_guests_guests_error_hide_media

Baffles? We dont need no stinking baffles!

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Actually...ya do. You'll blow smoke -at full throttle- if you dont got em.

 

[82sbshortbed]

How bout this? Never seen one.

https://privatelabelmfg.com/products/plm-power-driven-universal-oil-catch-can-breather-tank?variant=34352046243978&utm_source=facebook&utm_medium=cpc&utm_campaign=**LP+-+Prospecting+-+Catalog+Sales+-+CBO&utm_term=**LP+-+Prospecting+-+Catalog+Sales+-+CBO+-+3%+Combined+LAL&utm_content=**LP+-+Prospecting+-+Catalog+Sales+-+CBO+-+3%+Purch+LAL+-+DPA+-+July+2020&fbclid=IwAR286P6A1cDrzbrrKN-Nj--RECjPXYxtBt8kewwj_Mq8ZfJlHsf97ux8TAY

Hell yeah guys> i am dealing with pcv issues at the moment so this is a great thread. I had a horrible howl coming from my carb i blame the pcv for,"tested confirmed".
I ran it yesterday with the pcv
"venting" to atmosphere and wound up with a ton of oil on top of the engine. Blew right out the pcv valve on wot pulls.
Does anyone know how much oil should escape the pcv when hammering on it. I know it vents vapor but ive never seen one pump oil from it. Had to be 1/8-1/4 quart, and thats just what was left on the motor. Surely that much oil doesnt get pushed into the carb/intake every wot pull? UNless I have hella blow-by on this newly built motor. I do have baffled rocker covers and using a high volume oil pump if that matters.
Also i had smoke," like rings bad", when I would WOT before unhooking the pcv from carb...now I dont; So I know a ton of oil was getting into the intake every hard pull.

That does sound like a lot of oil. Maybe thats why they made this. Idk for sure but, something doesn't sound right.

 

[Frankenchevy]

The fact that someone has their original vacuum diagram with the pcv on the drivers side and vent on passenger seems to make me lean that way, but maybe that was a packaging deal more than anything

I guess a basic test could be to put a vacuum gauge in both sides and see if one pulls more, but I think it’ll pulsate quite a bit.

 

[Rusty Nail]

I told ya, this question is a trap.

Like none of these muggs got a passenger side breather tube connected to the air cleaner...gtfo of here!

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[Swearbody]

That does sound like a lot of oil. Maybe thats why they made this. Idk for sure but, something doesn't sound right.

I have a homemeade catchcan left over from an old turbo build. I can use it but im thinking thats just a bandaid for whatever is causing the blowby/pressure. I dont know though, just thinking it shouldnt happen unless something is fkd up. Im gonna try running a new pcv and then give it a day and check the intake for oil...if there is oil present ill install the catchcan. I also have a three way pcv i could try that closes under boost/pressure @1/2 bar but i dont know how much pressure is generated by the crankcase or how much flow is recommended, so im afraid it may cause a backpressure issue in the crankcase if it closes too early

 

[Swearbody]

Swearbody pcv is not your problem. Your fresh motor needs to be disassembled and examined closely.1st thoughts rings upside down or wrong size.2nd thought they reused pistons with damaged ringlands or didn't clean the ringlands.But if you are correct and really blowing that much oil out, you've got a bigger problem than crancase ventilation.

Hey bud...how you doing.
So that tap/tick we were discussing ended up being the pcv. Finally located it once it started howling. Noticed the tap went in rhythm with the howl, pulled the pcv and no tappy tappy.

Makes me think you are right.
Imagine the Bad cylinder ring allowing blowby in rhythm with the compression and causing the pcv to slam against the top of itself"pcv piston slap". Sounds reasonable right. same problem could cause all the bs ive been dealing with.

I did a compression test before i rebuilt the top end.IIRC Had 165ish on all but #3 and it was 155+ish . Ill do another comp check this weekend. If it has changed ill do a leak down test and go from there.

 

[Swearbody]

Too bad there isnt an expert here that can explain it all away.


Edelbrock "elite series" valve covers by chance? @Swearbody I threw a pair away because they dont have baffles in them.
A Sphincter says what?

xc_hide_links_from_guests_guests_error_hide_media

Baffles? We dont need no stinking baffles!

xc_hide_links_from_guests_guests_error_hide_media

Actually...ya do. You'll blow smoke -at full throttle- if you dont got em.

Im not usre of the brand but hey arent eddy's. The really common tall "Chevrolet" aluminum" covers is what I have. They are baffled though

You must be registered for see images attach

 

[SquareRoot]

The fact that someone has their original vacuum diagram with the pcv on the drivers side and vent on passenger seems to make me lean that way, but maybe that was a packaging deal more than anything

I guess a basic test could be to put a vacuum gauge in both sides and see if one pulls more, but I think it’ll pulsate quite a bit.

Same theory as to why the gas filler door is on one side versus the other.