Aftermarket Breather system - Atmosphere or not

Morning All

Been doing lots of searching on this subject as dont want to have a failing Front crank seal which its sounds to be down to high vacuum in the system. Now Some people have just put a catch tank between the 2 breather hoses on the exhaust side as seen here

http://www.max-boost.co.uk/max-boost/cylhead/crank_ventilation_2JZGTE.htm

And others have just vented the system to Atmosphere via a filter

Not sure how this is done though.

Which is best way to do this? Would it be best to put a catch tank in the system as stated by http://www.max-boost.co.uk and buy one that has a vent and filter on top.

At the moment my TT is running standard j spec turbo but will be going down the t67 route in couple of months

Thanks for your time

Morning All

 

Been doing lots of searching on this subject as dont want to have a failing Front crank seal which its sounds to be down to high vacuum in the system.

Not high vacuum, high pressure ie no vacuum...ie vent to atmosphere

Now Some people have just put a catch tank between the 2 breather hoses on the exhaust side as seen here

 

http://www.max-boost.co.uk/max-boost/cylhead/crank_ventilation_2JZGTE.htm

 

And others have just vented the system to Atmosphere via a filter

Not sure how this is done though.

 

Which is best way to do this? Would it be best to put a catch tank in the system as stated by www.max-boost.co.uk and buy one that has a vent and filter on top.

Vacuum assisted (not atmospheric), with a catch tank if you're worried about the amount of oil your PCV is passing.

At the moment my TT is running standard j spec turbo but will be going down the t67 route in couple of months

 

Thanks for your time

Get two bosses welded onto the intake pipe of the T67 to keep the closed breather system.

HTH.

Hi alex

Thanks for reply

So basically as ww.max-boost.co.uk has done with putting the catch can inbetween the breather hoses you just put the hoses into the intake piping of the t67??

Either solution is fine as long as it gets routed back into the intake eventually.

Crankcase pressure is your enemy.... crankcase vacuum is your friend

A constant vacuum in the crankcase will reduce the risk of oil seal failure & even increase power by reducing the oil thrown around by the crank as it thrashes about in the sump. Oil and air exist in the sump as a mist, and the crank has to thrash through this, which absorbs a small amount of power. A vacuum reduces this and also de-airates the oil, meaning more oil is available for the pickup in the sump.

The closed system is a good design, ensuring that there is always a vacuum in the sump. If you plumb the breathers to atmosphere then you'll lose this vacuum and risk positive crankcase pressures, which could blow the seals.

A constant vacuum in the crankcase will reduce the risk of oil seal failure & even increase power by reducing the oil thrown around by the crank as it thrashes about in the sump. Oil and air exist in the sump as a mist, and the crank has to thrash through this, which absorbs a small amount of power. A vacuum reduces this and also de-airates the oil, meaning more oil is available for the pickup in the sump.

Hmmm but your intake now contains oil vapour which reduces the octane therefore opssibly reducing power?

Hmmm but your intake now contains oil vapour which reduces the octane therefore opssibly reducing power?

Yes in racing applications, but, I think we have to look at this from a broader perspective...our cars arn't tuned to within an inch of their lives...

OEM's have systems that go into the intake...so it can't be that bad an effect.

If you're producing too much oil, you have far bigger issue's than reduced octane!

Yes in racing applications, but, I think we have to look at this from a broader perspective...our cars arn't tuned to within an inch of their lives...

 

OEM's have systems that go into the intake...so it can't be that bad an effect.

 

If you're producing too much oil, you have far bigger issue's than reduced octane!

 

True

Hmmm but your intake now contains oil vapour which reduces the octane therefore opssibly reducing power?

That's why racers dump the oil misted crank gasses (with all kinds of exhaust gas mixed in that goes past the rings) into an extractor in the exhaust. A little beyond most home builders & a real cat killer

And a catch can will reduce the vapour to almost nothing. Just the oxygen depleted gas left which doesn't burn very well.

TBH 150 to 200 litres a minute of crankcase gas is nothing compared to the total air intake at full chat!!

So is an aftermarket catch tank a good idea or not then?

I have been looking at installing a catch tank for a while now just never got round to it, have not decided if I want to route into inlet, exhaust or leave open though.

I currently run an open system with a small filter on the breather, not ideal and potentially dangerious

I only ask because since going BPU and running increased boost, some of my pipes/clips are not as good as they used to be and have noticed a fine oil deposit on the ex cam breather so I've bought a catch tank to collect it. However is this a sign of something a tad more serious?

So is an aftermarket catch tank a good idea or not then?

In one word..... Yes!

The main aim of the catch tank is to seperate the oil from the gas coming out of the crankcase.

Oil in the inlet system is not good for two reasons:

1) Pre-intercooler it coats the internals of the IC in oil, reducing heat transfer

2) If it enters the combustion chamber (which it is unlikely to do from pre-intercooler as the intercooler itself is a big catch tank) it will cause octane reduction. This is more likely to happen in the breather from the intake manifold.

So in an ideal world we'd have 2 catch cans, one for each breather (as the breathers should NEVER be joined together in their standard form).

For a racing engine these two catch cans would vent to an exhaust extractor rather than into the inlet, as the gasses are not ideal for ultimate power, but we're still after crank case vacuum.

I only ask because since going BPU and running increased boost, some of my pipes/clips are not as good as they used to be and have noticed a fine oil deposit on the ex cam breather so I've bought a catch tank to collect it. However is this a sign of something a tad more serious?

Pics??

If you increase power then you increase blowby..... based on the higher cylinder pressures and more leakage past the rings.

If you increase blowby then you increase the amount of oil carried over by that blowby, up to a point where the std breather system cannot cope with either the flow volume (resulting in a pressurised crank case) and more oil getting through to the intake.

Going BPU will no doubt put more blowby gas & therefore oil mist through the breather system, but I'm sure it'll still be within reasonable limits compared to the design limit of the system.

Engines like Jamie's that are running monster boost & fuelling are where the system would not cope. That's why his system is so much bigger

Stick a catch tank on it and it'll all be ok

And while we're on about catch tanks, the best design internally is with baffles as per http://www.max-boost.co.uk/max-boost/cylhead/crank_ventilation_2JZGTE.htm But this can reduce flow. Another good method is to have the pipes entering the catch can at different lengths, with the inlet pipe going deeper into the can that the outlet. This forces the gas/vapour/mist mix to hit the bottom of the can and then go back up to the top before exiting, ensuring that the oil drops out of suspension.

Pic as promised. I had a new cam cover gasket fitted at the last service in October at the same time I went BPU, and noticed it the other day.

Via the intake side, both cam covers are linked centrally, the turbo side cam cover is then linked into the intake tract before the turbo. Even the big powered supra's that dont run an intake still need an evac system in place. Were running one similar to this..

 

[qimg]http://img.photobucket.com/albums/v256/spitwad/newebay242.jpg[/qimg]

available from summitt Racing.

A nice pic of an exhaust extractor setup from Bondango. These can be purchased from Ford. I have the P/N somewhere.

And see this thread for lots more info:

http://www.mkivsupra.net/vbb/showthread.php?t=77973

Pic as promised. I had a new cam cover gasket fitted at the last service in October at the same time I went BPU, and noticed it the other day.

Errrrrrrr...... forgotten something Doug???

Edit - And as if by magic it just appeared !! Wierd !!

Looking at the picture I'd say the clip has relaxed and allowed vapour to blow out of the joint. New clip time?? A good type is this Unex one in stainless. They always stay perfectly round.

Well I'be bought one of these from envy so hopefully it'll do the trick.

http://www.mkivsupra.net/vbb/showpost.php?p=1288657&postcount=1

Well I'be bought one of these from envy so hopefully it'll do the trick.

 

http://www.mkivsupra.net/vbb/showpost.php?p=1288657&postcount=1

If its got 15mm diameter fittings it'll be fine. Can you get into it to make the inlet pipe reach lower into the tank??? Or has it got internal baffles???

It looks like the gases will go straight across to the outlet.

If anyone is interested in a really effective aftermarket breather kit then pm me before you spend hard earned cash on what's currently available in the aftermarket for our cars.

I developed what I believe is the ultimate crankcase evacuation/breather system for 2JZ eqipped mkiv's. It is only suited to non standard turbo installs but I could probably modify it to fit stock twins if somebody really wanted it.

No-one sells a kit like this one, it's taken a while to put together and I am still waiting for a few final parts but it should all be complete in a weeks time. This was designed for a single turbo Supra I was buying but the sale fell through and the kit is now not needed.

As soon as I have all the parts together I'll photograph it and get a for sale thread sorted.

if you do fit a catch tank, fill it with stainless gauze (i used a scouring pad), this improves its perfomance

Right, my catch tank arrived today. Had a good old look at it and decided that it wasn't upto the job. It was a universal jobbie anyway, but it was baffleless, with no ability to insert one, and the inlet and outlet were both at the top of the tank on each side.

So it's going back. But I do need one. I was looking at two on the MVP website.

Here & The Greddy 9mm pipe (no direct link)

I like the idea of fitting a baffle/sump collector and it being easy to "service" any ideas chaps?

check on my section for after market breather systems i have been making these for a while now currently have one off my setups running on Jamie p car

Got a link or a pic of the catch tank wayne. Can't find it in your section.

Here & The Greddy 9mm pipe (no direct link)

9mm may be a little small if that's the hose size it uses. The 2JZ breathes quite a lot, and you don't want to go restricting the breathing as it could result in positive crankcase pressures.

This is the one I got. Its actually very good

http://cgi.ebay.co.uk/New-F1-Z-15mm-Fitting-Oil-Catch-Tank-Made-in-Japan_W0QQitemZ280093341939QQcategoryZ72205QQcmdZViewItem