To breather box or not breather box...that is the question

[i_luv_my_bus76]

I rebuilt a single port engine... I used yamahabond to seal the case halves and permatex aviation dealer for everything else.

Then engine has 1400 miles on it. I thought that I had bad valve covers because I couldn't get oil to stop leaking from the covers no matter what i did... i changed multiple gaskets and used different sealers nothing worked. I bought a set of bolt on valve covers and that seemed to fix the issue at the heads.

Now I notice oil leaking from behind the crankshaft pulley and I have a spot of oil where I park now...so now I believe I have too much crank case pressure and its finding the path of least resistance.

I heard a 1641 shouldn't need a breather box, but I feel as if i could benefit from one. I ran into a guy at a cat show with a 1776 and he said he had the same issue and a breather box cured his oil issues.

Any thought/suggestions?

[theKbStockpiler]

How is the case vented?
_________________
My beetle is not competing with your beetle. I have the yellow beetle in my town. There is a red one, a green one ......
Use all safety devices including a mask.

[i_luv_my_bus76]

[Krochus]

I swear Volkswagen people and that stupid breather box infatuation. Where do dumb ideas like this get started?

OP you don’t need a breather box. But you do need more venting most likely which is never a bad thing. I think you are on the right track looking at that unused fuel pump provision
_________________
1970 Turbo Baja Bug Turbaja 2165 t3/t4 Speeduino sequential EFI LS3 coil on plug ignition

1965 Chevy c30, Microsquirt turbo aluminum 5.3/nv4500

[theKbStockpiler]

One passage on the case is all that is mandatory.

I would make sure that your plumbing and such is not blocked somehow even though it is not a likely. You can only directly vent to the air cleaner. If you vent to the intake it needs a PCV valve.
_________________
My beetle is not competing with your beetle. I have the yellow beetle in my town. There is a red one, a green one ......
Use all safety devices including a mask.

[i_luv_my_bus76]

So don't vent the heads...use the fuel pump block off?

[67rustavenger]

Yes.
Don't vent the valve covers. Unless the valve cover spigots are welded in place.
They will leak.
This is a 1641. Not a 2332.
I built a 2180 and only vent through the filler tower.

Good Luck.
_________________
I have learned over the years.
Cheap parts are gonna disappoint you.
Buy Once, Cry Once!

There's never enough time to do it right the first time. But there's always enough time to do it thrice.
GFY's Xevin and VW_Jimbo!

[k-weaver]

[i_luv_my_bus76]

[modok]

Do what you have to do... but I just hate how it's so much self induced suffering.

So you've got a 1641 with a after market breather that doesn't breathe very well, so you blow off the valve covers, so buy bolt -on valve covers, now your building a breather box.

If you just UN-DO whatever you did to cause the problem, then you won't have any more problem, it would have been less work in the end.

Use good rings, good cylinders, put the stock breather back on, no problems, easy to say now, and maybe that's now the best solution at this point,....but, next time you'll know.

[theKbStockpiler]

[i_luv_my_bus76]

[modok]

Yes, the passageways are too small.

[67rustavenger]

Is this the engine you're working on?

If it is. You're likely getting oil puddled up in the vent tube to the right carb.
The vent hose should drain back into the filler tower and eventually the crankcase.
The way it's oriented in the pic. Trapped oil is being forced up the vent tube, causing the oil deposits inside the carb body.
Try tightening the filler adapter so the vent tube is above the tapped hole in the filler neck. That way it will drain properly.

Good Luck.
_________________
I have learned over the years.
Cheap parts are gonna disappoint you.
Buy Once, Cry Once!

There's never enough time to do it right the first time. But there's always enough time to do it thrice.
GFY's Xevin and VW_Jimbo!

[i_luv_my_bus76]

[i_luv_my_bus76]

[modok]

Well, we've all done it. Really, blame society.
You didn't design that oil filler, nor manufacture it, nor market it, but you did bolt it on.

[Krochus]

That particular brass fitting on your filler is likely quite small internally adding to your issues.

I actually like that filler on my 2165 but I use it in conjunction with both valve covers vented all ran to a buggy style breather.

Buy an fuel pump block with a fitting and run that to the other valve cover and I’ll wager your problems will disappear
_________________
1970 Turbo Baja Bug Turbaja 2165 t3/t4 Speeduino sequential EFI LS3 coil on plug ignition

1965 Chevy c30, Microsquirt turbo aluminum 5.3/nv4500

[74 Thing]

Get rid of that crap aluminum oil filler you have on your car and put the stock filler with the downdraft tube with the rubber sleeve on the bottom. Then run a line to a breather box or catch can or soup can or beer can or whatever you want to call it and run another hose from the fuel pump block off to the can as well. Get rid of that hose to your air filter.

The crap you have on there now uses a 1/4npt brass fitting-take it off and look at the inside diameter of the hole and compare it to a stock filler that has an opening and a down draft tube that are both larger than you are currently using!

[i_luv_my_bus76]