Verhagen82

iTrader: (1)

Do you have to run a PCV valve or can you block off the vacuum nipple?

I simply just dont like the looks of it, i have edelbrock elite valve covers, each with only 1 whole in them; i have a oil fill cap on one and a air filter breather on the other.

skirkland1980

iTrader: (2)

yes. cap the nipple

Verhagen82

iTrader: (1)

Is this gunna do my motor any harm capping it?

Dustytrix

iTrader: (3)

As long as the motor can breathe it will be ok the filter on your valve cover will cover it.

Verhagen82

iTrader: (1)

So if thats the case, and everything should be fine regarding the breathing, what do i do with the vacuum nipple on the carb? If i straight up cap it off will that cause any problems with the carb itself or the rest of the vacuum system?

Apeiron

You can cap it off, but you really want a working PCV system.

Verhagen82

iTrader: (1)

Can you tell me why? besides emmisions that is...

skirkland1980

iTrader: (2)

vacuum can increase HP but the pcv is just air flowing through the crankcase. i think the pcv system may increase windage, but thats just my opinion, i have no proof.

t-top havoc

iTrader: (3)

OR---
You can give me the motor!!

JK!!

For a daily driver, it might keep the emissions.
For a strip car, IDK benifits.
skirkland & the other performance gurus will point you in the right direction!!

one92rs

iTrader: (5)

the pc system pulls excess crankcase pressure from the engine that builds as it is running. its best to have one. can be run without it. but i wouldnt do it. especially if it is mostly street driven. if it is mostly a race car then it can be done away with.

Verhagen82

iTrader: (1)

But wont a straight up air filter breather do just fine at letting the crankcase pressure out?

skirkland1980

iTrader: (2)

i've been drving my s10 for almost 3 years, every day, avg 20mi., and no problems other than a very very small front seal leak. not sure if its related. i think the pcv system is mostly to keep crankcase vapors out of the atmoshere...AKA emissions......thats my opinion i have no proof other than my own personal experiences. dirt track racers sometimes run very long races and only use breather filters.

one92rs

iTrader: (5)

pressure built inside the engine can cause leaks. and dirt track cars rebuild there engines often. we dont want to.

Apeiron

So you don't have nasty crankcase gasses making acids in your oil.

skirkland1980

iTrader: (2)

my oil leak may or may not be from the lack of pcv. i'm just saying if you have some kind of vent you should not have a crankcase pressure-related catastrophic failure.

one92rs

iTrader: (5)

no not catastrophic failure. just like stated above. acids eroding the engine away over time. a lot quicker than without it. trust me i have seen it within my 23 years in the field.

skirkland1980

iTrader: (2)

well, i know until the 2007 diesel emissions standard all/most diesel engines just vented to the atmosphere. if any type of engine would suffer from contaminated oil it would be a diesel engine. you know, 22:1 compression ratio an 30,000 psi fuel pressure at the nozzle tip.

skirkland1980

iTrader: (2)

i can do this...the oil in my truck has at least 1000 miles on it. i'll take a sample, pay the $20 and have it analysed and post the results.

Verhagen82

iTrader: (1)

HAHA yes! SOLVE THIS WITH SCIENCE!?!?

Air_Adam

A working PCV system will keep your oil cleaner longer by sucking out harmful fumes before they become harmful oil contaminants, keep the inside of the engine in a negative pressure which can help oil aeration, it helps ring seal and helps to keep various 'problem' gaskets from leaking... like oil pan and valve covers, and it keeps the outside of the motor and engine bay cleaner by keeping away those oil fumes that just 'vent' all over everything.

Its got SO many more benefits than just being an emmitions device... you'd be wise to keep it functional. PCV valve on one valve cover, breather cap on the other. Or be like me, cut a hole in the back of the manifold where it only covers the lifter valley (not into a runner) and put in a grommet and PCV valve, then a breather in each cover. This is basically what GM did on the LT1. Looks much cleaner, and works beautifully.

Verhagen82

iTrader: (1)

Can you take any pictures of this? I guess im just turned off by the looks of the PCV as this is going to be a show car but i am going to drive it so i dont wanna do that much harm to the motor if i could prevent it.

blue85305

if you're not going to run a pcv valve then you really should run another breather. if not vacuum created on decel will suck in gaskets and cause oil leaks, only one way for air to get in or out. and diesels have a legitimate reason for still running drip tubes, seeing as they have no throttle blades and therefore create no vacuum to operate a pcv system.

Air_Adam

This is an intake I did this with a few years back.

89_ho_rs

that is a nice setup. i have 2 breathers and was wondering about a pcv. i like that setup alot.

stroker_SS

How bad is oil consumption with that setup?

Air_Adam

Basically none. It just sucks fumes out of the lifter valley, and fresh air comes in through the valve covers - and theres alot bigger 'gap' between the lifter valley and PCV valve with that setup, then there is between the rockers and PCV valve if you put it in the valve cover.

Keoman

iTrader: (3)

What grommet did you use for that and where would I find one?
Also what vehicles came with a straight pcv fitting like that? All the ones I have seen are 90*.

1982Z28Modified

Just my two cent worth... The engine does not need fresh air in the crankcase or valve covers. The best method is a PCV in each valve cover. Fresh air equals moisture which is not good in an engine. It will condense in the oil and start to break it down. No PCV's guarantee your oil will turn to sludge. Just my two cents. Dorman sells a grommet for about $5. Also putting a vacuum on the crankcase is a good thing. If you have an air breather you can watch fumes come out the breather. Solve it with science! The crankcase has positive pressure. The valve cover with the PCV has vacuum(negative). The pressure will flow to both the vacuum and the atmosphere (zero) in the breather.

paulo57509

The poster hasn't posted in two years. You'll probably have to look at several PCV valve grommets to find one that will work.

1. The PCV system needs fresh air to function.
2. Engine oil gets hot enough to "boil off" any moisture provided it is run long enough.

1982Z28Modified

Why do modern engines run 2 PCV's and no breather? My F150 has that setup and clean oil. If modern engines do it, why not try it. No engine pulls vacuum hard enough to "suck" gaskets in. If it did you gaskets were old or not installed properly.

Someone present a logical, fact based reason for not using two PCV's and no breather.

Keoman

iTrader: (3)

Lots of race engines run two PCV's or vacuum pumps to create vacuum in the crank to help the piston return to BDC faster. Faster / easier revving = more power available sooner.

This is not a PCV system however. For the concept of a PCV system to function, it is nessisary to have a breather. Pulling a vacuum on an enclosed space with no inlet does not yield ventilation. That's just logical. For air to flow IE ventilate the crankcase, there must be somewhere for it to flow from.

rusty vango

the "positive crankcase ventilation " system removes harmful fumes that otherwise would contaminate the oil. and it looks as if you have some major coin in it. do you really want to do anything that would shorten its life???

Keoman

iTrader: (3)

Remember, this thread is very old, I was simply trying to get a response out of Adam when I asked what grommet he used for his carb PCV setup he showed in a picture.

1982Z28Modified

Keoman... the pressure in the crankcase comes from ring blow by, which is constant. Pressure will flow from high to low. The engine vacuum will not pull fresh air in. Crankcase gas will leak out the breather.

Remember the original setup of PCV. The so called breather side went to the air cleaner with a small filer that was always soaked with oil. It was a **** poor design.

Remember this design comes from the 70's when emission control had just started. Do you really think that this system has not been updated or re-engineered?

You can run a breather. You don't have to use a PCV valve. But it will shorten engine life.

Logic and facts please.