Delete head breather and pcv?

[momento1]

Need some other peoples experience with this one.
I only just got the car back from a final tune after
My rebuild.

Currently my tuner who builds drag race engines for a living, has rearranged the breather system as he see it will work.
Im using wizards breather puck and i have the crankcase breather going straight to a catch can with no PCV and with a drain line back to the puck. And the outlet line is just open to atmosphere.
Now my tuner has chosen to plug the head breather completely. So its only breathing out of the crank.
The car is running fine and making good power but now on the street on had acceleration the oil is getting forced out the breather on the catch can.
Ive considered going to a much larger catch can to hold more oil during big long drag pulls before it drains back to sump.

What are other peoples thoughts and experiences with this?

[Thuppu]

I had just a system like yours, and had exactly the same problem. I flooded the engine bay a couple of times with oil in hard launches. Add a breather to the valve cover 1/3rd from the front and connect it to the same catch can. It will reduce the issue quite good. But if you wan't to resolve the issue 100%, then add a baffle plate to the sump that cover the rear end and also the block breather outlet.

[momento1]

Delete head breather and pcv?

Thanks thuppu
I actually have one of you baffle plates but i am yet to install it!
Looks like i will need to do it asap then

Also the block breather puck from wizard is fairly baffled and is loaded with steel wool however its still pushing past it as well

Cheers

[momento1]

Thuppu do you recommend closing up the rear head breather and putting a new breather on the top of the head towards the front only?

Because i find a lot of oil comes out of the back of the head breather, and thats why we closed it up for now

[diesel des]

Ok so breathers are complicated. The head on our cars has too much oil sitting arround and if you have a big breather on the valve cover this just encourages oil into the head and not to drain back to the sump which is a very bad thing. Just stay with the block breather and get a proper brain back to the sump at the front above oil level. I have a block breather that goes to 25mm as quickly as possible that feeds a separator. The separator drains back to the sump with a 19mm line. Get the baffle setup in the sump too and leave the head blocked.

A big separator just allows too much oil to get into the breather system and not enough in the sump. Not good.

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[Thuppu]

You could first try to fit the baffle plate and report back how it works. The problem with using only one breather outlet(block breather) is that when you accelerate hard oil forces up in the rear of the sump and soaks the breather outlet full of oil(the baffle plate will reduse this a lot). In the same time there will always be some blowby and pressure inside the engine, and when your only breather outlet is full with oil... Very difficult for the separator when pressurised oil is spraying hard, not everything will go back to the sump, some will blow out to atmosphere.

[momento1]

Thanks for your input des
basically my setup is running to a small saikou michi catch can (roughly holds approx 600-700ml) and the breather line hose is approx 20mm. Then i have connected a drain line of approx 10mm hose back to the breather puck.

However the catch can is way too small i think as it fills completely after 1 hard pull in a straight line and hen starts spitting out the outlet line.
i will post up a ghetto mock up i have made to try and catch the excess oil being spat out the breather when it fills.

I should just upgrade to a 2L catch can maybe which allows time for the oil to drain back

[momento1]

[Rusty]

Swirl pot. Job done. I spent ages designing breather system for my S2 and a swirl pot is more important than a catch tank.

[diesel des]

Ask yourself this question when sizing oil separators. Would I be happy with 2 l less oil in the sump. NO. Then you don't want a 2l oil separator. You just need one that separates properly as rusty has said.

I also agree with Thomas, and that is why I said run a 19mm line from the front of the sump above the oil as a return line. This allows the return to work like a breather if the block breather becomes covered during a hard launch round a right hand bend.

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[momento1]

Swirl pot. Job done. I spent ages designing breather system for my S2 and a swirl pot is more important than a catch tank.

Have you got an example of your swirl pot Rusty?

Does it also vent to atmosphere?

[momento1]

Delete head breather and pcv?

Ask yourself this question when sizing oil separators. Would I be happy with 2 l less oil in the sump. NO. Then you don't want a 2l oil separator. You just need one that separates properly as rusty has said.

I also agree with Thomas, and that is why I said run a 19mm line from the front of the sump above the oil as a return line. This allows the return to work like a breather if the block breather becomes covered during a hard launch round a right hand bend.

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So i need to make up a catch tank that can fit a large return line also. As the one i have returning is too small to do the job
And ideally run this return line as the same size as the breather hose (approx 20mm) and to the front of the sump.
Probably should be similar height to the breather puck location then

[diesel des]

This is how mine is done.

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[V6quattro]

What the f"uck are you guys doing with your cars? I don't even have a return line just a catch tank.

[s2dk]

Im using rustys swirl pot and have allmost no Oil in my cc not even after a Day on the drag strip
Allso uses sump plate from thuppu Stock breather on head
Works great