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timed breather vs. pcv valve


rider
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The idea of replacing the timed breather with a pc valve is the most stupid upgrade I have ever seen, to start with the pc valve will never allow enough air to be expelled to properly vent the crankcase to the level that the original timed vent did. Those who promote this deal as smokin somthin weird. I and Lorne have never seen a broken or defective timed vent with one exception, and that was where the roter was installed not indexed to the pin, as usual, sloppy work will get you nothing in return. Further, a pc valve of the wrong type/size can start to flutter at high speeds, and then friend, you can watch the oil flow. SB says it right, what is to be gained, anyone with any real knowledge of boxer type engines will poo-poo the hairbrained mod. It is so ill advised, but like many things out there in Dnepr world and elsewhere (Ural) It is started, and then takes on a life of its own, I believe this one started in merry ol England about 20 years ago, If not my apologies to the throne......Ken :unsure2:

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Actually I think the English just removed the breather, we don't have PCVs this side of the pond, at least not 20 years ago. Removing the breather valve rotor has it's merits if the pipe diameter is to small but I did an experiment (my first post infact!) where I connected a pressure gauge up to the dipstick hole. At anything over idle there was a vacuum.

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The idea of replacing the timed breather with a pc valve is the most stupid upgrade I have ever seen, to start with the pc valve will never allow enough air to be expelled to properly vent the crankcase to the level that the original timed vent did. Those who promote this deal as smokin somthin weird. I and Lorne have never seen a broken or defective timed vent with one exception, and that was where the roter was installed not indexed to the pin, as usual, sloppy work will get you nothing in return. Further, a pc valve of the wrong type/size can start to flutter at high speeds, and then friend, you can watch the oil flow. SB says it right, what is to be gained, anyone with any real knowledge of boxer type engines will poo-poo the hairbrained mod. It is so ill advised, but like many things out there in Dnepr world and elsewhere (Ural) It is started, and then takes on a life of its own, I believe this one started in merry ol England about 20 years ago, If not my apologies to the throne......Ken :unsure2:

 

Is it normal to have air pulses out the crankcase filler hole when the dipstick is removed and the engine is running? Or does this indicate a problem with the breather?

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Yes it is normal...it is called the "path of least resistance" :unsure2:

 

See here for opening the distributor cover and getting the breather and pin. Easy. Much easier with the engine out of the frame but not necessary. If you find the pin on the cam gear is broken (it is just a press fit into a hole on the gear) you can pull one of the alignment pins for the valve cover gasket and use it. May need to be ground/filed a bit to fit.

 

http://myural.com/removing_and_reinstalling_the_di.htm

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Yes it is normal...it is called the "path of least resistance" :unsure2:

 

See here for opening the distributor cover and getting the breather and pin. Easy. Much easier with the engine out of the frame but not necessary. If you find the pin on the cam gear is broken (it is just a press fit into a hole on the gear) you can pull one of the alignment pins for the valve cover gasket and use it. May need to be ground/filed a bit to fit.

 

http://myural.com/removing_and_reinstalling_the_di.htm

 

Super!! Thanks a lot. This will help soooooo much!!! It just put 1/2 cup of oil into the catch can on a 12 mile ride..

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And before you go to all the trouble...do you know for sure the breather is not working? It is pretty fool-proof, breather just rides on the cam and is timed by the slot in it that mates to the pin in the cam gear. Only problem it can have is pin falls out or breaks...very rare.

 

Unscrew the 90 degree elbow for the tubing to the air filter, shine a light down the hole, use the kick starter to turn the engine over and watch to see if the breather turns. You'll see 2 opposed holes whiz rhythmically if all is well.

 

There are other things that can cause you to peez oil out the breather.

 

Oh yeah, forgot to mention that I agree with Ken...replacing it with an external PCV is silly.

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And before you go to all the trouble...do you know for sure the breather is not working? It is pretty fool-proof, breather just rides on the cam and is timed by the slot in it that mates to the pin in the cam gear. Only problem it can have is pin falls out or breaks...very rare.

 

Unscrew the 90 degree elbow for the tubing to the air filter, shine a light down the hole, use the kick starter to turn the engine over and watch to see if the breather turns. You'll see 2 opposed holes whiz rhythmically if all is well.

 

There are other things that can cause you to peez oil out the breather.

 

Oh yeah, forgot to mention that I agree with Ken...replacing it with an external PCV is silly.

 

You are correct, we looked in the hole and unfortunately saw no rotation. I followed the instructions and removed the cover.

 

The pin was broke off but that's not the worst part. The breather was stuck in its "race" the area around it blackened from heat and cracked. As if somehow the breather did not mate up well and slowly wore into the timing cover before coming to a dead stop breaking the pin. We had to use a large socket and hammer to get it out. Ill upload some pics if you guys are interested. So as of now i need to replace the timing cover and breather. But at least i feel better knowing whats going on.

I just need to order a cover, breather and gasket. Any thing you fellas can think of?

Again, thanks for all the help!!!

Will

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