Exhaust Backpressure causing front pulley leak?

[Mberglo]

Just completed a 4300 mile cross country trip in my 71 Westy. Engine is 1776 with dual Weber IDF40, W100 cam, stock bus exhaust, running Rotella 15w40 T5 Syn Blend. This trip was the first time I've had the bus at constant highway speeds for extended periods, and it was the first time I've seen oil spray on the topside of the engine. I find it interesting that the spray is on the passenger side, as the pulley turns the other way and I would expect it to be on the driver's side. I have an OEM pulley of unknown origins, and I have my oil filler neck vented to the passenger side carb air cleaner. I expected I would just buy a new pulley when I returned, but I found one comment about excessive exhaust backpressure creating the case pressure. I have plans to upgrade the muffler to a Vintage Speed, so I'm curious if that alone might relieve the symptom.

[evanfrucht]

I think you read about excessive crankcase pressure and are confusing it with exhaust back pressure. Perhaps if you had extremely high exhaust back pressure it could bleed into the crankcase somehow through the exhaust valves and then rings, not quite sure.

There could be an underlying cause such as poor ring sealing or something, but a quick and effective remedy could be just adding to or opening up the breather system. That might be enough to stop the pulley leaking. You could do a leak down test if you wanted.

Off topic, and lets not get into it here, but that's not the best oil to use. I used to use Rotella diesel oil but eventually realized there were much more appropriate options. 15W40 is also pretty thick IMO. Your oil pressure could be high. I would use 5W30 or 10W30 for your climate if it has a stock oil pump.
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1967 Bug ( the daily rod )
1964 Fury Wagon ( the pavement shredder )

[MrWhoopee]

Front is front, the pulley is at the rear.

Needs more breathing/venting. It's a common problem, the stock venting is barely adequate for a 1600. Lots of threads on the subject, search for "breathing" or "breather".
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Craig ('51 WASP)
Rosie ('63 Double Cab)

[Alstrup]

The oil is not the problem. And 15w40 is fine for that climate.

I would check the inside of the right air filter. If it is plastered in oil mist there is a problem. If it is reasonably clean you have an "external" problem, such as a bad pulley or similar.
I agree that the breather capabilities are on the small side when you go directly from the filler neck to the carb. You need more "condensation" area.

The largest impact of the stock muffler is elevated head temps. That again can lead to high oil tekmps and then you can experience increased blow by etc etc.
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https://www.thesamba.com/vw/forum/viewtopic.php?t=435993

[frenchroast]

Couple of things:
1. I can see the oil spray that came off the crank pulley and it is slinging in the direction that the motor turns.
2. The crank pulley is threaded to drive oil back into the case but if the cupped oil slinger is installed backwards, it might not be able to keep all the oil in on extended drives.

Do you know if it was dripping out before? Maybe it turned from a small drip into a small flow that was now getting slung off the pulley?

The crank case breather tube looks like it is dry/not soaked so crank case pressure might not be excessive.

[oprn]

Maybe someone machined off the pulley hub to fit an oil seal but the case does not have one. Check the bottom of the breather down tube, that should give you a clue as to how much crankcase pressure you have. If it excessive you should have a puddle below it every time you stop.

Now - that breather has to change! 1) you will be filling your carb full of moisture rich crankcase snot, 2) you are drawing major road dust up the breather down tube directly into that cylinder bank unfiltered!
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We had the stone age, the bronze age, the industrial age and now we are in the age of mass deception and mind control for corporate profit. (The mass media age)

[evanfrucht]

Your pulley appears to be the earlier original German Type 1 pulley from mid 60's type 1 before they changed the design aesthetics wise. I don't think they reproduce that style but I could be wrong or maybe they did at one point. So I don't think the pulley would be the problem unless it got damaged at one point.

Perhaps the case was machined for a sand seal?

Slinger backwards is a good thought too.

As for the breather, a quick solid fix to try would be to get an aftermarket filler cap and then either weld a 1/2" tube to it or attach a fitting to it somehow. You could use something like the Empi breather fittings, although I've heard those are terrible as far as quality/design. Then get a little breather filter and attach it to that new fitting on the cap. Basically a custom breather cap that fits the stock oil filler... if you can live with the look it might be a viable lomg term solution.
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1967 Bug ( the daily rod )
1964 Fury Wagon ( the pavement shredder )

[Zed999]

My builder doing this was enough to make the same or worse mess. I forget whether it was fitted the correct way round but I think so.

I know how he did it, I've done it myself, he dropped the crank assy into the case and missed.
I only found out because there was so much wrong I lost my temper with it one day... is this the right way round? It's been a while.

After I rebuilt, same case crank and pulley it didn't leak at all despite chuffing a gale through the breather. The drain was not blocked with sealant. The only change with any possible connection to throwing oil past the pulley was a new concave washer.

[Busstom]

You mean people actually "drop" crankshafts into crankcases? And they "make" it? What constitutes a make as opposed to a miss?

Since literally no one could ever "drop" a crank into a case and miraculously line up all three bearings onto the dowel pins, I'm gonna go on the record here and say there is absolutely nothing to be gained by dropping a crank into the case with enough force to bend the oil slinger. That's what the concave washer is called, an "oil slinger." The concave face goes to the rear.

[txoval]

If the concave washer was backwards, I honestly don’t know how the crank would once the pulley was installed. It would shove the washer into the case.

If you somehow drop the crank when placing it into the case, you better remove everything and start over...checking more than just the washer

[mark tucker]

needs better breathing with big dia hoses so the oil does not get pushed up the hose. also get that hose off the air cleaner,you do not want any oil or oil vapors in the chambers or to cake up on the back side of the intake valves.
be sure there are no dips in the vent hoses. and if you put them on the valve covers they should be aimed upwards, not sideways to collect oil.and try to not locat them where oil may be thrown off the rocker arm or valve. I usualy position them between intake and ex valve'son 1&3 cylindr or in the center, or for the empi style covers or others that have the ends cast for installing the vents do them at a angle upward not horozontle. min of 1/2" inside hose dia should be used or bigger 5/8 would be good. and the fitings should have a big id too.I usualy ream them biger. I like a 5/8" hose barb and trim the barb down on lathe so a 1/2 hose will fit tight. 5/8 hose use bigger barb& then turn down the barb. I dont use the breather boxes, I use the yingyang valve cover breathers( look like a K&N filter) hung upside down so no h2o can enter. no leeks no mess.
also if you have the steel sand seal they may come loose if they are installed to far. I like the rubber seals better.( CB I think is where I was getting those.) but all this may or may not work if your ring seal is not good. and thats another matter all togeather.

[Zed999]

[Igpoe]

Twin road draft tubes on 1835. 5k miles on motor, no leaks, breather clean inside.
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'73 super.

[Busstom]