Breather system

[Thundercat]

Hi all, anyone got any drawings of how to pipe up a oil catch tank and do away with standard breather system set up. Thanks:confused:

[Junglist]

Hi all, anyone got any drawings of how to pipe up a oil catch tank and do away with standard breather system set up. Thanks:confused:

:agree: i could also do with this info :)

[Junglist]

im guesing a catch tank would just fit in the pipe that connects to the telephone hose ??? am i correct ?

[James5]

im guesing a catch tank would just fit in the pipe that connects to the telephone hose ??? am i correct ?

Yes, but you can amend the breather system alot more than that if you want.

[RAGOONEY]

This is how I had mine.
I had a breathable cap catch tank, routed one pipe to the rocker cover, took off the original breather pot near waterpump and replaced with second pipe.
But I'm sure there are other variations too...:)

[Thundercat]

What was your car like for mot emissions, did you remove air restrictor pipework and blank off inlet manifold? thanks

[Alastair]

http://www.rtoc.org/files/Technical%...r%20system.gif (http://www.rtoc.org/files/Technical%...r%20system.gif)

Cup mod for the breather system. The details are in the technical area of the FILES section. :)

See here also:

How does the breather system work?

Manifold vacuum is used to suck the oil vapour from the rocker cover, mixed with clean air from the filter. The main purpose is to keep the inside of the engine (crankcase, rocker cover etc) at a lower pressure than outside the engine, so the oil seals and gaskets don't leak oil into the environment.

There are obviously refinements on some cars, such as the separator pot on the GT Turbo that helps return liquid oil droplets to the sump, and the one way valve that stops it blowing from the manifold into the rocker cover when on boost (not a good idea!). Under boost conditions, the vapour is sucked into the turbo inlet by the air rushing from the filter. Not ideal, but it's got to go somewhere...

It relies on the vapour being sucked by the manifold. A small amount of air is mixed to ensure that the vapour burns properly in the cylinders. The amount of vapour and air is controlled by the restrictors in the pipes.

You can fit a small filter instead of the connection to the air filter hose - which will prevent oil vapour going into the turbo. However, as the small filter won't provide the 'suck' that the fast flowing air into the turbo does, the breather system won't work as well. But well enough for a well maintained engine. The filter will almost certainly get clogged with oil eventually though, and need cleaning.

You can also put a catch can in to prevent any oil vapour reaching the manifold at all- again, relying on the pressure in the rocker and crankcase to get the vapour out. Not as effective as the standard setup, but prevents any problems due to oil going into the intake.

Oil catch tank, do you need one?

If your car is blowing oil then yes, if not no.
Some people remove the breather system and in it's place just have a filter on the rocker but usually some oil comes out of this. Or they pipe the rocker to a bottle or catch tank. Some are more sophisticated and called oil separators, they swirl the oil mist that is leaving the rocker cover / crank case and the oil collects and drains back to the sump. The 5GTT already has one of these fitted, the swirl pot above the water pump, but there is a limit to how much it can cope with. There are larger versions available to cope with more mist.
It seems that the breather pipes that go to the manifold are there to reduce emissions as having some oil vapour going into the combustion reduces nitrogen oxides, or something, so that's good. Not required for track cars.
It's best to have good crank case breathing or the oil leaks out from the oil seals and maybe past the piston rings and cause smoke from the exhaust and excessive oil consumption.

[James5]

There are a fair few variations of the breather mod.

Personally I have always preferred the less pipes the better, I did the following on mine:

Remove 1 way valve on inlet manifold and replace with bolt.
Remove all the orginal breather system pipework,
Remove the oil seperator pot.

I then run a pipe from the rocker cover to the a T Piece that attaches to the oil return to sump pipe (where the oil seperator pot sat) and the other side of the T piece then goes to another pipe to a catch tank (be it a fancy alloy jobby or plastic bottle it does the same thing)which then vents to air or through a small filter.
Just been through an MOT about 3-4 weeks ago venting to air with spot on emissions.

[James5]

Looks like I should have refreshed my screen:o

[Alastair]

Also from Coupe manual in files section to give you a clus about the letters on the above picture:


Oil system
Installation of walls at the oil sump (anti-wave plates) to avoid oil movements and eventual oil pump air sucking.
Modify the crankcase ventilation system as follows:

　
A=Open air, D=Minimum diameter 16 mm.
The rest of hoses, supports and 'oil fumes tank', may be removed.

[Thundercat]

Thanks all, sheds some light on the subject will get fitting catch tank and pipes later. :)

[Junglist]

There are a fair few variations of the breather mod.

Personally I have always preferred the less pipes the better, I did the following on mine:

Remove 1 way valve on inlet manifold and replace with bolt.
Remove all the orginal breather system pipework,
Remove the oil seperator pot.

I then run a pipe from the rocker cover to the a T Piece that attaches to the oil return to sump pipe (where the oil seperator pot sat) and the other side of the T piece then goes to another pipe to a catch tank (be it a fancy alloy jobby or plastic bottle it does the same thing)which then vents to air or through a small filter.
Just been through an MOT about 3-4 weeks ago venting to air with spot on emissions.

what about the hose that connects to the rear bottom ofd the carb is it removed ? what about the hole on the carb , left open ?

[Kris M]

you mean the inletmanifold ??

Unscrew the one way valve on the passenger side of the manifold ( on the back) and replace it with a bolt and fiber washer to block it off :)

[scratcher]

Red arrow goes to rocker cover, green to catch tank.
And as James said, an M8x25 washer in the manifold where the one way valve lived.
http://i59.photobucket.com/albums/g319/pimpscratcher/SDC12202-1.jpg

[Junglist]

http://www.rtoc.org/boards/attachment.php?attachmentid=68&d=1221290763


i mean hose number 11 , i have this connected to a t-piece ,one way goes to top of the oil seperator pot and the other to my catch tank (used to go to air filter hose) .
does that sound right ,, ive got air sucking into the catch tank fairley strong ? , should i remove hose 11 then and block up the holes ?

[Junglist]

Red arrow goes to rocker cover, green to catch tank.
And as James said, an M8x25 washer in the manifold where the one way valve lived.
http://i59.photobucket.com/albums/g319/pimpscratcher/SDC12202-1.jpg
does that hose in the catch tank / lucazade bottle suck air in ?? mine does :scratch:.
i have the carb breather (hose 11) also plumed into the same pipe from the top of the seperator top to the catch tank

[Junglist]

http://www.rtoc.org/boards/showthread.php?t=11036

[Bass J]

Ive also ran the cup breather mod ..but didnt blank off the bit on the manifold ..instead cut a hose and put a bolt in the hole of the end of the hose i cut....if theres air escaping ..will it cause the engine to stall at junctions?

[scratcher]

does that hose in the catch tank / lucazade bottle suck air in ?? mine does :scratch:.
i have the carb breather (hose 11) also plumed into the same pipe from the top of the seperator top to the catch tank

The hose to the bottle has no vacume on it, it only breathes outwards.
It could be your one way valve throwing it out on your set up?


Ive also ran the cup breather mod ..but didnt blank off the bit on the manifold ..instead cut a hose and put a bolt in the hole of the end of the hose i cut....if theres air escaping ..will it cause the engine to stall at junctions?

I tried a bolt in the hose when I first altered my breather set up and it made lots of black some at higher revs for some reason. It was cured straight away when I removed the valve and blocked it off on the manifold.

[Bass J]

The hose to the bottle has no vacume on it, it only breathes outwards.
It could be your one way valve throwing it out on your set up?



I tried a bolt in the hose when I first altered my breather set up and it made lots of black some at higher revs for some reason. It was cured straight away when I removed the valve and blocked it off on the manifold.
Ah niceone ill sort that when i have spare time :laugh: cheers :agree: