Crankcase Breathing

[Piledriver]

is this applicable to type 4 engines also? thanks.

It's easier, the breather chimney nicely holds two SS woven pot scrubbers to separate the oil, plus they are "heated" so you don't get vaseline build up.

I just redid my setup using some $2 1.8T PCV check valves... very low operating pressure, fast and high flowing for their size.
Work quite well, I use manifold vac and an accumulator setup to keep some vacuum on the case at all times, or at least for as long as possible, and one of the check valves is a dump from the 1/2 rocker box, only flows in case of pressure...

On a racing rig running at WOT constantly this would not work well without an additional vacuum source like the exhaust or a vacuum pump.

I have a vacuum break setup so I don't pull more than 5-7mmHg vacuum, it' purges into the 3/4 rocker box to assist the oil in getting back down to the sump.

I'll probably still end up with a Krankvent.

[rowster]

I have a stock 2liter type 4 engine. I'm planning to put it in my 1973 beetle (IRS). I will be using a CSP upright fan conversion kit to adapt a type 1 doghouse. I was planning to set it up with PCV's. I'm kinda lost on how to apply this crankcase breathing fix. thank you Piledriver.

[andy198712]

pile,is that the vw 1.8T engine there from?
cheers

[Piledriver]

pile,is that the vw 1.8T engine there from?
cheers

Yep, it uses several of them to provide PCV steering to keep boost out of the crankcase.
Study the vacuum diagram for that motor and you will understand much.

You can get replacement valves aftermarket, they look absolutely identical to the "dealer" ones, AFAICT they are the same part for ~1/10th the cost.

[andy198712]

Cheers I'll get on eBay and also take a look at said diagram.
Thanks

[Piledriver]

Just checked with my "supplier" and he got the valves I'm using direct from US Plastics.
They have larger versions as well.

http://www.usplastic.com/catalog/item.aspx?itemid=23369

[andy198712]

postage might suck for me but thank you, i know what i'm looking out for now

[tango]

I knew this thread was here somewhere.. I saw it a long time ago and ended up ordering a reed valve which sat on the shelf until now.

My TIGing is out of practise so its not pretty but I got there.

Its sort of a reed-valve-breather-pot thing.

It replaces the breather tower on the 914 and has a reed valve in the bottom with connectors for each head vent and a large out to go to the intake. I bent up a new bale wire out of a welding rod and tried it, with the heads connected it inflates a glove cable tied to the output so air is moving in the right direction. I think venturi effect should add draw also when I actually connect it.
Tempted to rig up some sort of gauge to see what it does to the case pressure, my boost gauge shows vac but I am not sure if it would register case readings this small well enough.

[Steve Arndt]

Awesome! Did you use a 2-stroke type intake reed?

[tango]

Yes, a cheap one off ebay for a 50cc I think with stainless reeds, £10/$15. Some scrap ali and a few hours remembering about AC TIG balance etc

[Piledriver]

Sweet!

I suspect you will still need a tiny hole for oil to drain back through, even with the pot scrubbers in the chimney.

Aluminum is always ...interesting... to weld.

I'm stuck at 60Hz but the Synchro seems to always get it done, even if the bead/HAZ is a lot wider than I'd like..

[hugging corners]

there are multiplicity of different thickness or reeds avalible from polini or mallosi for mopeds together with different mounting blocks for easyer fabrication. I wonder if that could help fine tuning the pressure. Since i build mopeds and have a bunch of extra reeds i will experiment with that.
scroll the page down to see reeds

https://www.treatland.tv/SearchResults. ... reed+valve
https://www.treatland.tv/polini-2-petal ... -block.htm

[JWP]

Sorry for resurrecting an old post, but I wanted to get some opinions from Frank and others about a breather system from a modern large CC sport bike.

I've found that Honda CBR's seem to have an electric vacuum pump that attaches to the top of the valve cover and likely routes the outlet back to the intake some how.

http://www.ebay.com/itm/HONDA-CBR-954-R ... 0814758833

Any thoughts on using something like this? I like Franks setup with the 2 krank vents and ideally would want to drain the catch tank back down to the sump. However at 280 for a pair of Krank Vents it's hard on the budget.

[JWP]

Edit it looks like that piece is just a valve rather than a vacuum pump.

So to expand on that many modern cars have electric vacuum pumps, wonder what could be made to work with those.

[andy198712]

Cheaper to use a exhaust evac system surely?