Correct way to vent the crank case

[BFB]

It’s funny how big of a debate this subject is and its funny how most of you will all agree that no two engines are the same yet will make a blanket statement for or against extra case venting.
Also think ya’ll are trying to discuss case venting pro / con for two different reasons whether it needs it for windage or blow by and one guy will say he’s doing it for windage and the next guy says first guy has blow by issues. Heh heh. Just an observation…
Far as a 1/4” line not being big enough to do anything and that the alt stand should be sufficient, think of that this way. Ever pour something out of a container with just a spout vs. a similar container with a small vent tube ? Even a small vent helps the container breathe and circulate so it flows better without “gulping”.
Ive never had an engine have issues from being over vented, i have had them have issues from not enough.
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"how am i supposed to torque the rear wheel nut to 250 ft lbs??? " - clonebug
An interesting thing happens in forums where everyone starts parroting the same thing and "common knowledge" takes over.
Most experts aren't.

[raygreenwood]

[chrisflstf]

More opinions are always helpful, even if you dont agree with all of them.

I particularly like jim martins simple test of a glove on the breather stand as a simple way to measure blowby. Thanks for that info

[Alstrup]

Next problem is, that that glove will be blown to pieces on anything off the shelf. In the last 4-5 years I have not seen one full set of cylinders being perfectly round. Sometimes 1, maayybe 2, but never a set. Which is why I hone everything before assembly.
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https://www.thesamba.com/vw/forum/viewtopic.php?t=435993

[chrisflstf]

Dont know what your defination of perfectly round cylinders are, but this is mine:

https://ace-engines.com/product/aircooled-vw-cylinder-honing-services/

[motomwo]

I noticed the alternator and generator stands spout filler passage tapers from 1" diameter at the top to 3/4" diameter at the lower end. There is enough material/casting to bore the hole straight through to 1" diameter. Boring it out 1" all the way through would allow for more breathing/venting capacity. Not sure why vw designed it that way... Just something I was thinking about.

Marty
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1961 Bug, 2276 cb wedge ports 44x37 11.1 comp fk10 1.5 rockers 48idf's 1 3/4" header Rancho pro street trans SAW axles Airkewld 4# narrowed beam, Koni shocks, Airkewld dis brake all around. 5.5/4.5 BRMs

1966 Bug, 2127, panchito heads, fk8, 1.3 rockers, dual 44idfs, 1 5/8 merge header, Rancho pro strt flyer, empi axles, Airkewld's 4" beam and discs all around and adjustable shocks. 4.5 & 5.5 BRMs

[modok]

YEP, there are at least five different kinds of stands, actually a lot more than that. And the size of the cavity and passages is not all the same.

Most of the new builds I see people using alternators, but a surprising number of us are still using a generator.
Should do a poll

[67rustavenger]

[oprn]

Me too! The generator on my sand rail does everything I need to do. My Manx copy came with a type 1 engine and generator too and it worked perfectly fine. The ONLY reason it has an alternator now is because the type 4 engine I have in it now came with one.
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Our cars get old, we get old but driving an old VW never gets old!

[slayer61]

Love my 2 wire alternator. An idiot could hook it up and make it work... wait a minute... an idiot DID hook it up and make it work!
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[greenmachinemike]

So after reading all six pages of this, I came to the conclusion that it’s probably best to experiment with different venting to figure out what works with my engine and driving habits. I’ve had a pretty bad spray all over my engine compartment since installing a rebuilt engine, which I recall having the same issue during the last couple years of its previous incarnation as an 1835 that I built from a new as41 braziian case last century. It’s now a 2021. I only had the oil line from the alternator stand to the street on the old engine, this time I transferred the breather box from the engine I used a couple years in between, a 1968. I only connected the 1-2 side valve cover, the fuel pump block off and the alternator stand to the box, cheapo Empi, and it would cover my engine and back of my bus and leave a puddle under the crank pulley every time I make the trip from Oakland to Santa Cruz, about twice a week. If you’ve seen my green and black bus on the 880/17 you would probably guess I have crankcase pressure issues, because I’m going 75-80 mph! So today I connected the fourth outlet of the breather box to one of my stupid expensive CSP air cleaners, I didn’t enjoy drilling and tapping such a beautiful piece of art, changed the oil, wiped down every bit of oil I could see and drag raced it up and down the 24 going through the Caldecott a couple times. I’m sure I looked insane. But I am happy to report a complete lack of macro-lubricating! Time will tell if sucking in all that Penn grade I used to wipe off with paper towels will reak havoc on the unlucky IDF who’s only crime was being closest to the unused port on the breather box, but for now, problem solved. If it’s only temporarily successful, I’ll try something else since many of the builders I respect in this community can’t seem to reach a consensus.
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59’ Kombi, 64 Manx

[slalombuggy]

[slayer61]

[slalombuggy]

[onehappykombi]

Hello all!

My engine is a 1679, very close to stock but with a sand seal pulley. It’s having occasional crank case pressure problems. I think I just need a small bit of additional ventilation with the following restrictions:

- mechanical pump so can’t vent there
- don’t want to vent valve covers
- as simple solution as possible

Would it make sense to just add a venting port at either of the locations I marked below with red circles?

Thank you!

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'56 Early Split & '69 Early Bay

Overlanding the USA
Camper special engine build

[raygreenwood]

Um....what is that fat hose doing right next to the smaller red circle? Isn't that a vent port?

Man that is like a 12mm ID hose. If you are still having venting problems with that....drilling another hole next to it will likely be of no help.

Describe what is happening in detail and I would bet that someone here has a better answer.....like oil slinger issue or too much oil at the sand seal point etc.

Ray

[EVfun]

6 pages and I still don't know the correct way to vent the crank case.

I do know THIS is the incorrect way!

(image by fastorange72)
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[Glenn]

Maybe bad rings are causing the internal pressure.
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Glenn
74 Beetle Specs | 74 Beetle Restoration | 2180cc Engine
"You may not get what you pay for, but you always pay for what you get"

Member #1009

#BlueSquare

עַם יִשְׂרָאֵל חַי

[motomwo]

Where or what is the hose connected to on the end that is not shown in the picture? Maybe a fitting/hose nipple that has a much smaller inside diameter than the hose?

Marty
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1961 Bug, 2276 cb wedge ports 44x37 11.1 comp fk10 1.5 rockers 48idf's 1 3/4" header Rancho pro street trans SAW axles Airkewld 4# narrowed beam, Koni shocks, Airkewld dis brake all around. 5.5/4.5 BRMs

1966 Bug, 2127, panchito heads, fk8, 1.3 rockers, dual 44idfs, 1 5/8 merge header, Rancho pro strt flyer, empi axles, Airkewld's 4" beam and discs all around and adjustable shocks. 4.5 & 5.5 BRMs

[ZEKE65]

I added a 3/4" filter to the bottom of the stock filler drain for a vent.

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1965 VW Sedan, 1968 C10 Step BB, 99 C5