I'm considering blocking off my head vents and running a -10 or -12 breather solely from the oil filler/breather to a Morosso breather tank (or the like). The idea here is to keep the crankcase at a lower pressure than the heads so the oil tends to move from high pressure to low (aka from the heads to the case).

Anyone else doing this yet? If so any comments or pictures?

Thanks!

I am doing this. Not sure I can tell a difference but it is less places to leak.

BTDT. A single -12 line from the chimney is all we ran on our F-Prod car. The oil will return more quickly from the heads to the crankcase with no head vents.

This was a hot topic here on World a year or so ago. I was amazed at how many people got down-right hostile at the suggestion that head vents were not only unnecessary but counterproductive.

The drain back slots on a type 4 are restrictive. If the heads are vented the crankcase pressure interferes with the oil draining back from the heads. Close off the head vents and the pressure differential between the rocker chambers and the crankcase goes away allowing the oil to flow through the narrow slots without interference from crankcase pressure.

My 75 2.0 did not have head vents. Maybe the factory decided this was not necesary.

Len,

Do you have a picture of that? I was thinking of just drilling out the stock location (PCV valve) to a -12/-10. I'm only running 6200RPM *max*. But I'd like to see what others have running. No need to re-invent the wheel...

The drainback slots on a type 4 crankcase aren't narrow, nor are they restrictive.
Their cross-section is at least as large as the cross-section inside a pushrod tube,
and they're shaped in a manner that ensures adequate flow without any likelihood of becoming hydro-locked.

Crankcase pressures are unlikely to ever be above 1.01 atm., vented or unvented.
It doesn't take much of an opening to bleed off that pressure. The diameter of the opening affects velocity of flow far more than volume.
Those very low pressures have little to do with preventing oil from draining back from the heads.

A venting system ensures equal pressure in the 3 chambers of the engine when they're all connected to a central cannister that's open to the atmosphere.
No differential will exist.
On the other hand, when only the crankcase is vented, there will certainly be a pressure differential due to the constant supply of oil into the rocker boxes.

Anecdotal evidence to the contrary (factory design changes, etc.) notwithstanding, there's no proof that unvented heads are beneficial to oil control in comparison to a well designed breather system on a carbureted T4 engine.

BTW, the cross-section of three -8 hoses is greater than the cross-section of one -12 hose.

Hey Aaron,

Breather/Drain Back Discusions

Here is a link to a topic a while back...there is a link in this thread that leads to the 'heated' discussion Len mentions. That thread lead me to vent to the filler neck only. Len answered on pg 6 that venting back to my stack should be fine. If you don't mind a little bullshit (well maybe more than that?) there is a lot of good info in that thread.

Keep pushing on the envelope

Aaron, I welded a -12bung to an aluminum plate that bolted to a cross bar that mounted in the chimney. It would be tough to do that with the engine in the car.



I don't think my 1300sq.ft. home is too small either, but some would disagree.


Anecdotal? I'll bet that we did far more testing of oil systems and breather systems than you have. And we approached it with an open mind, something that is essential to progress. Several breathing systems were employed and observed in action on Jakes chassis dyno. We then went out and beat holy hell out of the engine on the track. Two full seasons of competition and one cup of oil in the overflow can total for the entire season!

Ask yourselves this. If you have a breather in the heads and the oil line comes loose from the breather can, why does it puke oil out of the line from the head? Think about that for a moment.

Personally I don't care if folks vent their heads or don't. I'm not selling breather cans and I have no vested interested in how people deal with this. I do advise all of my customers not to vent their heads. So far everyone has been positive about having less oil lines and leak potential.

I've been through this topic before (and was genuinely flummoxed by some of the defenses of vented heads) and I have now said all I have to say about it.

But Chris DOES! SURELY he isn't up to allowing folks to find out that
they don't need an VERY expensive catch can from him......

T4 heads don't need venting, PROVEN FACT.

Don

WOW! Just checked your site...can with T and 2 fittings is $209.95?
No wonder you are adamant about convincing everyone that venting IS necessary!


The economy is bad enough, our politicians rape us enough....find some other 'Snake Oil" to sell us please!

Don

This type of shit stirring is unhelpful, unproductive, and NOT welcome. Grow up. Or if you can't do that then at least PRETEND to act like an adult.

What is the worst thing that could happen from not venting the heads?

FlatIV, it depends on who you listen to.

I have head vents, and they are currently capped. I've seen no adverse effects and take the car to redline every time I drive it (which has not been often this summer ). I have not seen much of a difference from when I had my vents running to a breather box.

I do have the case vented, and don't plan on changing that any time soon.

Zach

Touch a nerve? I don't need to grow up, I need to NOT get screwed unnecessarily!

Let it go.....you don't have a dog here.

Don

This weekend I wrote an article that covers the testing that Jake and I did on this subject and posted it to my website. Our methods, why we did the tests in the first place, our observations and our explanations of what we observed are all in there.

Folks can (and likely will) debate this subject as long as these engines exist, but this should at least put to rest the notion that we made up our position on the subject just to be provacative.

http://www.hamincgroup.com/type4-test.php

Thanks Len, great writeup! Next time you see Rick and your Dad, tell them
I said Hello and I'll be sure to stop by and see them ASA I hit the States again!

Don

On this specific subject I find it very interesting that the factory changed its mind more than once...on all the air cooled motors.

Rich

The only thing i can add is that if your motor is vented, make sure you either use the vents with a breather, or block them off whichever you fancy. If you don't do anything you will be spraying oil everywhere and that oil will collect in the engine bay. Take a corner quick enough and that oil ends up on the street.

You don't either, Don.....Just saying?
Hope ya make it back home safe??

It's all to plain that's it's a personal thing between you and Chris..You can keep that shit private or take it to the Sandbox. Your hijacking of threads here get's old and I'm sure other's agree.....Maybe I shouldn't be baiting you be repling to this but your are one Classic Piece of SHIT....

Sorry to stay OT, Aaron....

It's Ken, Don....It seems you misread two things above? You making it back safe was very sarcastic on my part....Humm, still is!!

I have noticed you seem to only come here when you want to stir up shit when there are specific dogs in the fight. It just makes you look like an ass.
Instead, why don't you hang around and contribute more often? Maybe even something constructive?

These are friends, Don. You show up here just to stir up shit, so I got more "dog" here than you do. So act like an adult, or if you can't do that then if there's any place on the internet where you're still welcome go back there.

.

Wow, looks like everyone had their coffee this AM!
BUWAHAHHAHAHAHHAHAHA!

I dare say that Chris ended THAT friendship with a can of Tangerine Orange spray paint.

Now THAT is DIS-RESPECT! How about somebody goes to YOUR shop and shits in the corner, HUH?

YOU guys might feel like you have to, but I don't have any reason to kiss a Tangerine's ass.....

What I can't build, I'll buy somewhere ELSE.

Don

Well, that CERTAINLY sounds like a threat to ME!

MOD, make sure you PM this guy and ask him to change his post.
I have been attacked here and I demand justice!


Remind you of those others that whined to you on the last thread?
BUWAHAHAHAHQAHAHHAHAHAHA!

BTW MOD, I'm not kidding.

Don

Damn dude, I really was hoping you would man up. I really believed I might like you and look forward to your contribution here. But in front of ten thousand 914world members you have chosen to be an asshole. Congrats. Douche.

rand, we might have to go all alphy on this guy!!!!

I think this dumb-ass is immune to alphansims. First class douche bag. I really wanted to believe he was the kind of guy who could be fun bullshitting in a real garage. But he has proven to just be an ass.

I know he thinks he is cool, and is probably doing this for kicks and hoping to find some kudos on Jake's forum. But that just makes me think he is even more of a moron.

It's like this:
But yet I wonder if even Jake the big dog is impressed with this asshat.

"d"star must have been a reference to his performance in school.....

or just short for " dumb ass star"

or "dick head star" if so he needs to join the phallus cranium club and stay away from us ass hats.

but i'm pretty sure it's short for "dim star" not very bright at all!

Man up to WHAT? That I bring to light, that which would prefer to stay in the dark?


You could like me, but you would have to think for yourself and not follow
the shepard around so closely....

I'm not an asshole, no matter if I seem like it on a VW/Porsche site or two once in a while.

Don

Alphy? BUWAHAHHAHA, You don't even know what it means!
I went off on that guy years ago, before this site OR you came in the picture.
HE learned HIS lesson.

Don

I'm great fun to BS in the garage.
Come visit, you are wlecome anytime.

As for Jake, WE have had our times also, it isn't all .

Don


Don

More attacks from the forum?
Unheeded by the MOD?


Anywho, DStar came about before you were BORN.
Before the INTERNET.

It was for Death Star, or my name, Donald Starling.

It was Dstar on the only online access available in the 70's, Compuserve, then DStar2000 on Fido-Net, then after all the 2000 this and 2000 that, I got tired of seeing the "2000" in everything, so I changed it to DStar5000.

There's your history lesson.

Don

related pic

Good shot of how the oil gets all over everything! It is nice to get back on topic!

It has been my experience that flat motors seem to have much more oil in their internal air due to the proximity of their crankcase vents to all the whirily bits. Also remember the cam/lifter going in & out in close proximity the the heads oil drain tubes from the heads of a T-4.....that cannot promote good drainage.
I remember an old pic of some plexi-glass valve cover showing the valve covers 2/3rds full of oil at higher revs. Personally, I don't give a shit how, but you need to deal with that oil loaded windage. Chances are there will be an honest difference of opinion on that and anyone that disagrees with YOU is an asshat.

Well said

I really think everyone should act a little more professional.

If we were professionals we'da given up on ths place years ago.....many have.
This rough & tumble just like real life. I am a professional asshat & able to deal with it. If ya can't stand the heat........

many post opinions and speculation about a topic. many post something they read elsewhere as if it were their own experience. Jake is a data collector like me. I respect those who do. if you are a do-er, than post pics, data or real world results.
for those who use this BBS as a place to learn, as I do, I hope you can see the difference.
allways evaluate the source.

I have a 76 2.0. No head vents and no PCV valve. Just a hose from the oil filler to the air cleaner. I was wondering if this was normal. I guess it is. Looks like they toyed with this quite a bit and ended up being almost like the old days. They vented into the air cleaner instead of the atmosphere. I am sure there is some draw from the air cleaner.

I just don't like the name calling unless it's in good fun. I didn't take it this time as good fun. Opinions are like assh*les; everybody has one. There's something to be said about aggressive behavior.
I use Chris' collector can on my 2.0. It seems to work fine. Just my $.02 worth.

I wanted Chris's not because it was absolutely necessary for operation but because it has a great appearance and would keep oil from splashing all about. That said, I just didn't have the dough so I bought a 22.00 EMPI catch can "for offroad use only" that seems to catch the oil at least.
http://www.empius.com/vwcatalog/2011/51.html

The point is there are options out there that range from free/DIY to high end systems that bolt on, and which one to buy depends on available cash and how handy you are.

I personally have a lot of respect for anybody who is working to make anything to help us make our beauties drive, especially when they offer a high quality product.

I make no judgement on whether or not personal attacks were deserved, but they certainly do not belong in a place where so many come to learn.

Careful what you wish for! And i'm not kidding either ...

I don't really care what anyone does with the head venting.
However, the crank case vent went to the plenium, which has suction. And the hoses on the head "vents" went to the clean air side of the air filter box. This means that clean air was drawn into the head, down the tubes, into the case, out the breather, and into the intake.

And I haven't "learned" anything from this site in years.

I have the Tangerine kit and its $189 without the t - piece that you may not need, also includes shipping in the US. Its very well made and designed. If you think its too much money than don't buy it..there are other options out there like the CB performance kit that needs parts and work and not even close to the cool style of the Tangerine kit. Not sure why you are acting like you are right now...but I think the car is better with the kit especially when you switch to dual carbs like myself. Cheers!