Hi everyone, I went for a spirited drive last night and came back with a huge oily mess all over the engine. I have dual carbs and no crankcase breather as I wasn’t aware the need of one, what do you all recommend? I have a 1.7 block and heads that are now a 2056 and would like to put one in that is as simple as possible. Hoping something that just connects to the oil fill tower. Thanks!

Following since I need one also.

Some good info here:

http://www.914world.com/bbs2/index.php?sho...=78073&st=0

Simple way is as the factory did it, most the 1.7 oil towers have a breather where the PCV valve is located, cut a hole in one of the air cleaners braze in a small piece of pipe you can connect a hose from the breather. 1.8 oil tower has a pipe where the hole for the PCV valve goes, omits the valve.

@mgphoto my issue or thing I want to avoid is getting the oil vapor and film into my air cleaners and into the carbs, I’d like a solution that doesn’t involve getting gunk in the carbs and avoiding the spill of oil I just had at the same time. Hoping both are possible, I just don’t know what kit/brand of crankcase breather to get

This was on my last 2.0 with carbs. Catch can that was vented under the car. Kept everything neat and clean.

valve/flame arrestor is inbuilt into the oil cap itself for 1.8 L jet!
same as D Jet but different.

nice thing about the EFI cars is the oil vapour is fed in after the air cleaner filter saving that from getting doused. won't solve OP's concern as its hard to dump into a carby car without going in before the filter.

EDIT - i think VW managed to do it on the twin carby versions of 1.8 engine but its not individual air cleaners. they had that single air filter box with the flat ducts heading off either side to the twin carbs. the crank case vent line fed in on one of those ducts i think after the filter. you kind of need one of those style air cleaners which were really only around for the factory twin carb engines with pathetic solex carbs.

@mtndawg @mtndawg looks awesome, that would be perfect. So to try to understand this, you have 2.0 heads which also vent correct? So you have oil vapor/air breathing from your oil tower and each head into the oil catch can, then filters, and comes out of the catch can which vents to the atmosphere and is simply air or vapor and not actual oil right? Do you remember where you sourced it?

@wonkipop the OEM did it right with FI and the way it breathed but if I did it with carbs it would dump into the filter and eventually deep into the carbs and make a mess correct?

yeah i was just editing my post above having remembered that the carb aircleaner follows the same principle as EFI which has the feed duct down to the throttle body.
you got a better brain than me.

i think @bbrock (? think i got the right forum member there) built himself a homage aircleaner for much bigger carbs like OP has.
its in his restoration build thread. he did a real nice job making that aircleaner himself.

@barnfind9141972 i found the images of 1.8 twin carb factory euro spec engines.
one from 74 euro 914, other from 74 euro vw 412.

i lied. or am half mistaken. the crankcase breather line comes in right above the filter.
technically though it is after the filter so the vapours are in the airstream being drawn to carbs rather than perhaps dousing the filter or going through filter.
you can also see that its not a straight breather even with the carbs - the breather is a pcv with a valve operated by intake vac from one of the carbs. i think that stops situations where you get a lot of oil sucked up out of the engine or drawn up out of engine. can't remember exactly how these things really work. i think it is that intake vac situations close the valve. but i am probably wrong.

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@wonkipop wow, that’s definitely big brain stuff there. A very German approach where I’d like to take an American approach haha, as simple as possible

i think the catch can is going to have to be your answer as others suggest above.
pretty much what they did on all the racing porsches etc and a lot of race cars actually.

I bought that catch can from some online retailer. My thinking was that if I vent into the atmosphere there would be no vacuum pressure in the engine. Smelly engine vapor was non existent. The idea of the can is that you catch oil condensation. In reality though, gravity just put the oil back into the filler, never a drop of oil in the can. The heads and the top of the engine (oil tower) all vent via the can. I ran a line to the rain drain hole because it doesn’t rain on 914’s in California.

@mtndawg gotcha, yeah the oil condensation is what I want to catch to keep it off the engine itself. After driving the car hard have you ever noticed oil coming out of the hose you have venting out under the car?

The Tangerine Breather Canister. Collected vapors drain back to the engine via a small line connected to the tower. No oily mess. I can't imagine venting to the atmosphere with just an open line. Kinda bush.

HAM and Jake did a test on breather setups years ago. Still relevant.

Breather Test Link

Based on their analysis I use a late 2.0 fill tower plumbed to a catch can I made a mount for that sits above the middle of the case. Rocker vents are plugged.

I have seen quite a few setups where there are hoses attached to the stock Djet PCV used through '74. That PCV will do absolutely nothing without manifold vacuum from the FI plenum or other source. Hoses connected from a breather box(EMPI style is pretty common) to air filter tops with one down the the PCV will not draw enough vacuum to open the PCV to allow ventilation.

The bugpack breather is the most economical unless you craft your own/fabricate. I was running mine in the same location as SirAndy in the link above. Mount it right to the firewall. I am also on board with how Jake and others plug the head vents. The hoses not only get in the way, but they also are a real pain to secure hose clamps all the way down in there even with carbs and small hands. You can either just vent to the box or hook up the 2 additional ports to vent into the tops of the carb air filters.

Here's how I have mine set up as @wonkipop mentioned. It is basically the same air box used on a carbed euro 1.8 but with custom intakes to mate to the 40IDF carbs. I had to move venting inlets slightly for clearance with the raintray, but kept them close to the factory positions. The crankcase vent dumps in above the filter but doesn't seem to carry enough oil to gunk it up. Hasn't been a problem after 3,500 miles anyway. The factory dumped the oil breather vent into the right intake downstream of the carb so I did the same but put the inlet just on the airbox side (but well downstream of the filter). I get a bit of oil film just downstream of that hose inside the intake, but have yet to see anything build up on the carbs. Seems to be working well.

I like connecting the line to the airbox. This is how I would do it if I did it again.

Here’s the link to my set up.

LINK TO MY SET UP

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Ditto on my dual-Dell race car.

http://www.tangerineracing.com/crankcasebreather.htm

EDIT: I'll offer "lessons learned" on the race car.

Early days, I had a problem with the valve cover vent lines. Two different yet related problems: one, the swaged tube would actually pop out of the head casting on long corners, dumping oil all over the track. Two, I plugged the heads and was then running vented valve covers and the line itself actually popped off the tube on long corners -- dumping oil all over the track.

In that last case I actually "field fixed it" by drilling a hole through the clamp, hose, and tube and ran a split-key through it to keep it in place. Worked for the weekend.

Last year I left the head castings plugged (threaded it for NPT fitting) and ran un-vented valve covers...at that point, I was noticing significant oil weepage around the perimeter of the valve cover and drippage onto the header. It didn't make too much of a mess and didn't keep me off the track, but I still didn't like it.

Note I have NONE of these problems on my street 2L with plugged (welded) heads and stock un-vented valve covers.

Here's the thing: I read and agree with the HAM link posted in #17 above. I had welded a 3/4" tube in my oil tower and vented that to a Tangerin Canister. Yet I still had those head/vc/line problems.

Where I think this study lacks data - and why it may apply primarily to street cars - is that their testing was done with a static upright engine, no side loads. Best I can figure what's happening to me is that on long extended corners (Lime Rock Big Bend, for example) I'm getting oil pooling in the valve cover, which is eventually blocking the vent port(s), causing some pressure. Since this liquid cannot easily escape up the vent tube, the liquid force is causing the tube/hose to pop off.

This year's version is a compromise. I'm now using aluminum bolt-on valve covers with AN-8 fittings welded on (thanks Chris!) which surely won't come off. The AN lines are going to Tangerine's canister which is hung on the rear firewall where the center latch was. The oil tower 3/4" fitting is still going to the canister, and I have a small (AN-4?) drain line coming off the bottom of the canister and going back into the tower.

I guess we'll see how that works out... - GA


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