why not to remove that rear rocker breather and pipework

[Dooie Pop Pop]

in brief i' ll tidy it up tomorrow as iv been asked about this by pm;-)

its the valve/breather at the rear of your rocker cover on the left side of the engine.

some people say it contaminates your air/fuel charge with emissions...

the way iv been explained it works is like this: its called a check valve so its like a switch. when your on boost it stays shut hence no alarming engine pressures ie boost level i mean. this is the clever bit:-D

when you let off it it creates a vacuum and draws fumes from the rocker ect into the cylinder....

the greenhouse effect is caused by carbon dioxide. CO2 absorbs more heat than oxygen hence the world heating...back to the r:-D

fumes/burnt gasses ie CO2 are drawn into the cylinders which helps cooling ready for when you stamp your foot down again when the valve shuts;-)

the reason why your cars popping more is because its running hotter than normal due to the loss of the cooling effects of CO2.

worms?

Stu

 

[powerfreack]

i think i have seen one before on a 10sec car from jamacia it looks like they use a sunny gti rocker cover

 

[jpward]

Erm i was under the impression that the Oil vapours in the Rocker cover would lower the octane of the fuel and why so many cars run the Crankcase breather filters

I still have my valve in place because i know its a 1 way valve and have a K&N crankcase filter attached on the metal pipe leading off beside the Coil pack, i now have a lot less oil in the inlet track and find the cars runs smoother and i also did this before fitting the goose and had NO poping before fitting it.

This Co2 wheres it coming from?

 

[geetee]

The CO2 may well have a cooling effect - but I don't want all that oily shite coating my intercooler thanks.

 

[stevepudney]

UUmmmm .................

Before removing my check valve and associated pipework I used to have a fast idle problem (about 1300 rpm) but after removing it all my idle sits nicley at 1050 rpm and although it does pop and bang alot more on over run I'm reluctant to put it all back and suffer my fast idle again.....................

Ummmmm :? :roll:


S

 

[andygtir]

steve couldnt that have been down to the pcp valve leaking?

 

[ashills]

if u run a catch tank that has a vent to air on it then u should remove this pipe or it will cause faster idle had it on my old car as it basically becomes a open pipe to atmosphere where teh standard breather goes back into turbo hose

and it coats the inlet manifold and pipes in muck

 

[turblio]

Great subject this one Stu, my inlet manifold was always bone dry with it connected but Alan is right about the catch tank bit, think its the nitrogens in the crankcase fumes that cool better than air as when you shut the throttle the one way valve opens and allows cooling air into the pistons, so if you disconnect these you get no cooling on over run (bad news!)

 

[campbellju]

Its an interesting idea but I am not convinced about the cooling affect of "air" compared to my oil cooler that is coating all parts of the engine in 80deg C oil or my blooming big radiator on the front that is taking all the heat out of the block

Not a chemist but I thought rate of heat ransfer was due to conductivity of the material and heat diffferential. This oil mist has come from the block so will not be cold air but likely the same temperature as the oil.

I would have thought its more the fact its an oily mist means it is cooling as liquid's transfer more heat then gases. (rather than O2 at 80degs transfering more heat than N2 or CO2 or whatever)

This sounds like "smoke and mirrors" to me. Pistions normally melt or break when the fuel goes bang, not on the overrun. I'd have thought only a couple of lean/hot "bangs" would negate any cooling affect you may or may not have made on the last overrun.

Ready to be convinced otherewise.

Jim

 

[turblio]

OK do this test run your car up to 6000rpm in 3rd watching the egt gauge then back off quickly and watch how quickly the egt temp drops, now disconnect the one way rocker valve and block the pipes and do the same test you will immediatly see my point...

 

[campbellju]

What were your findings? Like I say, I am ready to be convinced otherwise ;-)

 

[turblio]

My findings were the temps drop in half the time which is good enough for me! and I would have thought mr nissan spent a lot of time and money on these little pipes for some reason, anyway thats my results and quite convinced why they are there...

 

[campbellju]

Did it make any difference to the EGT when you started to accelerate again is my point though? Did the EGT take twice as long to go up again?

I'm not doubting the physics of it, I just think its "smoke and mirrors" compared to the cooling affect of a richer charge or a cool block and oil. I was chatting to Steve P on the phone about this the other day for ages and I still couldn't see it.

 

[turblio]

I know it takes some believing, but yes it took a little longer for my egt temps to increase if I were to floor it a gain as the temps were lower than they would have been if the pipes were disconnected (not massive but useful amount) Yes I have had some good chats with Steve too

 

[jpward]

My findings were the temps drop in half the time which is good enough for me! and I would have thought mr nissan spent a lot of time and money on these little pipes for some reason, anyway thats my results and quite convinced why they are there...

The only reason the Oil separator and pipes are on the engine is for the emissions like the carbon canister ;-)

 

[Odin]

What a load of hogwash, I think having a nice big alloy rad and 19 row oil cooler give me loads more cooling than that rubbish bolted to the top of my inlet manifold.

I've had them off for about two years now with no ill affect so far, But if you lot like to believe it's giving you some benefit then fill your boots lol.

Didn't help you out much did it Frank lol lol lol


Rob

 

[turblio]

Good technical advice by flubber man as usual :-> when your throttle butterflies are shut with the pipes disconnected it dont matter how effin big your intercooler is theres no friggin air getting past savvy?!! lol

 

[campbellju]

Yes I have had some good chats with Steve too

Steve couldn't convince me either but thanks for the EGT info, puts a bit of meat on the bone on what is actually happening.

 

[jpward]

Good technical advice by flubber man as usual :-> when your throttle butterflies are shut with the pipes disconnected it dont matter how effin big your intercooler is theres no friggin air getting past savvy?!! lol

One thing i am sure of here is that Running carbs when you pop of the gas its to do with the idle jets and mixture and exhaust leaks

not the mid or main jets so how would injectors play a part in this situation could the set up be Richer on idle due to having this closed loop at idle?

and therefore POP because of richer exhaust mixture? :?

 

[turblio]

Yes the idle mixture will be richer