Rocker cover set up myths?

[aaddzz123]

So I've been having a friendly yet some what heated discussion with Mr Lang about the breather system on the 4efte and the best way of improving it to also incorporate a catch can system.

My basic suggestion was to remove the PVC valve, use the space as another breather and block the hole on the inlet, run both valves to a catch can and port the top of the can so it can breathe properly... I suggested this through basic thought and looking at existing options. It's been used a lot and works. No recycled air going into the inlet because you've blocked it off, and technically "twice" as much breathable air...

Ryan has been suggesting another route which keeps the PVC valve and uses two catch cans. I don't completely understand it and don't see the benefit from it other than to catch excess oil and keep all of the standard set up. I think the only reason for the route would be to keep the PVC valve to keep emissions ever so slightly lower seeing as a company suggesting how to improve the system aren't going to take the blame for saying remove the PVC valve which in turn raises emissions coming from the car lol.

Anyone else like to pitch in on the discussion?

If there's a better way of doing it and there is actually a benefit then I'm sure everyone would like the information !

Big loves xxx

[ryan lang]

http://www.ukstarletowners.com/topic/43123-show-me-your-catch-cans/?hl=%2Bshow+%2Bme+%2Byour+%2Bcatch+%2Bcans

[aaddzz123]

Really can't be bothered to read 5 pages of posts lol!

Someone explain to me the benefit of keeping the PCV valve, using 2 catch cans and other bits etc over using the currently used "race spec rocker cover" set up?

[ryan lang]

its all in there pal, put the kettle on and have a read

[aaddzz123]

So from what I've read, the point of the lines being sealed and having a can is so that the vapors are sucked from the cover instead of there being no suction.... Yet there is enough pressure in the engine to push the vapors out anyway without the need for sucking them out... So its pointless? Just seems like a far more complicated, messy and no more efficient way of the two lines to a vented can lol. Other than cutting some emissions.

[AdamB]

I wouldn't advise running a catch can withno breather or dump to atmosphere as it will end up being pressureized and blow to shit. What I would say is too:

3 way catch can- Both rocker fittings to catch can then the 3rd port back to the inlet with the PCV inbetween. This allows both fittings to breath to the catch tank yet it won't be pressureized as it will recirc it back to the inlet, only when the pressure overcomes that of the one way PCV. Don't think you'll be getting the oil sludge back to the intake eitheras it will fall the the bottom of the catch can, best to line it with some wool or baffling.

[DevonGT]

I wouldn't advise running a catch can withno breather or dump to atmosphere as it will end up being pressureized and blow to shit. What I would say is too: 3 way catch can- Both rocker fittings to catch can then the 3rd port back to the inlet with the PCV inbetween. This allows both fittings to breath to the catch tank yet it won't be pressureized as it will recirc it back to the inlet, only when the pressure overcomes that of the one way PCV. Don't think you'll be getting the oil sludge back to the intake eitheras it will fall the the bottom of the catch can, best to line it with some wool or baffling.

Exactly how mine is set up.

[aaddzz123]

I wouldn't advise running a catch can withno breather or dump to atmosphere as it will end up being pressureized and blow to shit. What I would say is too: 3 way catch can- Both rocker fittings to catch can then the 3rd port back to the inlet with the PCV inbetween. This allows both fittings to breath to the catch tank yet it won't be pressureized as it will recirc it back to the inlet, only when the pressure overcomes that of the one way PCV. Don't think you'll be getting the oil sludge back to the intake eitheras it will fall the the bottom of the catch can, best to line it with some wool or baffling.

If you have both lines under the PVC valve how is the engine going to breathe when the valve is closed?

[AdamB]

It pressureizes the catch can so that you get no back pressure going back to the cover fittings during pulsation, this pressure then forces the gas back into the intake when the PCV is overcome.

[aaddzz123]

What :s... If there is pressure in the can then there is the same pressure in the cover if the fittings come from the cover to the can with nothing in between them? The whole point of a breather system is to remove pressure from the engine? Not pressurize it?

Am I being retarded here? Is there and point in a race cover? Will some people in the game set this straight?

[AdamB]

Theres not the same pressure going to the catch can all the time at a constant rate.

You do remove pressure from the crankcase, but the way I see it, if the catch can doesn't become pressureized then gas is going back and fourth from the valve cover until the catch can is full with shit and it has no more volume to fill.

If you use a 3 port can, both valve cover fittings to the can. Then the 3rd port to the intake mani through a PCV. Once the catch can gets to a certain pressure the PCV will open and allow the excess gas to escape. Remember we are not trying to catch air, but oil and carbon build up to stop contaminating the intake air charge. The catch can just have 2 ports and a port for an atmospheric dump, or filter on the top if you wish but this doesn't allow the can to hold any pressure and will just distribute the excess shit straight into the atmosphere. Which it is just cheaper and easier to have both valve cover breathers with a bit of silicone pipe strapped down behind the engine pointing towards the floor.

[starletburkie]

Fuck this shit is complicated

[Liam_D]

Fuck this shit is complicated

Amen to that haha!

[turbo Grant]

I do think your thinking about it too much. Just let the breaths vent to atmosphere. They only really return back to the engine to reduce emissions and smell

[funny onion]

Both mine are just vented to atmosphere with the port on the inlet blocked. No problems and no oil spitting out. One of them whistles a bit though :/ haha

[Socks]

Both my ports are to a catch can that is vented...

I wont be changing it either

[H_D]

Catch cans are a waste of money IMO and unwanted weight in the engine bay. I think breathing is more efficient if you just route the 2 pipes straight to the bottom of the car that way the gasses are being pulled straight out without having to build up in a can and go through a breather. Catch cans can also cause back pressure when you floor it.

The main purpose of a better breathing system is to get rid of crankcase gasses faster which is restricted by a catch can compared to venting the pipes straight out into the atmosphere.

[Starbo Moorley]

Can people post pics of there setups ? Easier too understand something with a picture lol.

[Ricky@Race-Tech]

Catch cans are a waste of money IMO and unwanted weight in the engine bay. I think breathing is more efficient if you just route the 2 pipes straight to the bottom of the car that way the gasses are being pulled straight out without having to build up in a can and go through a breather. Catch cans can also cause back pressure when you floor it.

The main purpose of a better breathing system is to get rid of crankcase gasses faster which is restricted by a catch can compared to venting the pipes straight out into the atmosphere.

Actually with the friction losses. I'd say the one breathing to the floor would have a greater restriction. Also any oil could find its way to your brakes/tyres. It will leave oil on the back of your car. (on the underside would actually be a good thing though haha) Oil would tend to "puddle" in the pipe and drip on your drive. You don't have a way of monitoring it.

I see your point, but for the cost of a tank of fuel or similar your better with a catch can. Also if you use good quality hose the hose length been longer would ofset the cost of the can.

[H_D]

In terms of the 2 hoses being mounted at the bottom with the exit facing the exhaust surely they will help the crank case gases to be pulled out much better than a catch can especially when the car is in motion. Il try get some pics up when it stops raining.

Personally i will not be using a catch can anymore and on that note is anyone interested in buying my old forge catch can lol

[Liam_D]

Mines setup with both breathers going to a catch can and then the catch can venting to atmosphere via a breather filter on top. It runs pretty good like this but I'm starting to think its the wrong way of doing things. Occasionally have to drain the catch tank which I don't think is meant to happen?

[pick1]

^^^^ I would presume u would have to empty it occasionally as it would fill up after time butane some one more in the know could confirm

[ryan lang]

its called a catch tank, because its there to catch shit you are supposed to empty it every now and then so dont worry about that part

ryan

[Liam_D]

Yeah I thought as much, speaking to a few other members and friends as they don't seem to ever have to empty theres so was just a little worried I was running to much pressure or something

[lukEp]

Google is your friend. I wouldn't bother with a catch can unless you do it properly. The reasons why you have the set up in the first place it to draw out the vapor/moisture from the engine which is produced from the cooling down heating up of the engine (produces condensation) and blow by. By just removing both pipes and connecting to a catch can that air is just mushing about constantly in the engine, it'll just get wetter and more contaminated the longer it just mushed about. So I'd recommend having at least one vacuum source or don't bother changing the standard system.