Oil Catch can - Need help

[Doug in San Diego]

Hi guys

Need help. I recently had a significant oil leak on my way to work (dripping from bottom)

I assumed it was my head gasket, but I took off all the plastic (so I could see) cleaned it up, and ran it. I could see no leak ( I checked, it still had oil)

It looked like it may have come from my homemade oil catch can.

When I took it apart the can was half full of oil and it looked like it may have been splattering from that area. Really hard to tell.

Here is the question- What would cause the can to be full of oil? Also how do you route the breather hose into your oil supply

Finally, Is the breather hose needed? Can I just bend it shut to avoid this?

USMarine is coming over tomorrow to put in new cams - Any final thought would be great

[usfmarine]

As you know I am no expert, but lots of oil out of the valve cover vent can mean rings going bad right? Never happened to me, but I thought I've read that from others.

Good to hear I can put faith in our head gasket installation tomorrow

[Rebel]

You might benefit from this info posted by Performancescoot in another thread, he had done a big bore kit and then found he was having a lot of oil blow out his crankcase vent hose.

Performance scoot posted this on another thread, does it sound familiar??? Check it out

"Anyway, the reason I torn it down after the first build is becuase I was having trouble keeping the oil in it. I had a balance tube between the oil fill tube and valve cover connected to an oil catch with a breather attached to that and it would pump half the oil out on a high rpm run and was blowing oil everywhere out the breather and valve cover gasket. It worked perfectly on my last engine so I had no idea why it was doing this. I couldn't figure out the problem, so I dumped the oil stick tube and just ran a tube to a catch can and then a breather. Still did the same thing, so I torn it down figuring something must be wrong inside with the oil pump or passages. So I resealed everything, and low and behold, still pushing oil out the beather.

I ended up fixing this problem by installing a PCV valve. It goes from a hose on the valve cover tube to an oil catch, another hose out the catch to an inline PCV valve to a hose connected to the vacuum port on the intake. I was a little freaked out on my first couple of rides thinking I was going to dump oil into the engine via the intake, but it turns out that negative crankcase pressure is the ticket to these engines! I've got about 75 miles so far with this set up and this engine does not leak a drop of oil, oil vapor is non-exsistant and it hauls ass!"

[kuzikood]

bad rings dont cause excess oil out of the head, if you have bad rings you loose compression and/or exessive smoke out the tail pipe . if you have exessive oil out of thge breather you have a differant problem all together .

[kuzikood]

there ar basically two style of airbox on the scoots one is under the seat with a long snorkle the other is attatched to the cvt case . on the under seat version the breather tube goes to the airfilter housing where the vacum from the engine sucking air into the filter pulls on the breather line . on the other style the breather line goes into a small chamber that has the clear drain tube on the bottom and a vacum line going to the intake . the catch can needs a source of vacum to work propperly and where the vacum is attatched should be away from where the breather tube exits .... very similar to a breast pump ill see if i can find a good pic to explain this

[kuzikood]

couldnt find a good pic so i drew one

[felliott]

Bad rings WILL cause high crankcase pressure which is vented by the hose from the valve cover. The reason for this is bad rings allow compression to slip pass the rings and pressurize the inside of the engine (crankcase). This pressure then pushes oil out the valve cover hose. If the rings on the piston had their ring gaps all lined up this will also allow compression to go right in the crankcase and also push oil out.

[Doug in San Diego]

Can you elaborate on the PCV valve set up

It sounds like this is my problem, because I removed all the old snorkle and now there is no vacuum on the oil vent.

What do I need to build this? Or what do I buy?

I don't think it is the rings, I did not line up the slots, and they are pretty damn new. (less than 200 miles)

Just tell me its cheap

[kuzikood]

if the rings were bad enough to let that happen ,, the motor would have extremely low compression propably not run at all . simple test for that , loosely set the dipstick in the crankcase, tether it soi it doesent fall out , go for a ride if oil is still blowin through the head then excessive crank case preasure is NOT the problem

[performancescoot]

Nov 15, 2009 22:04:32 GMT -5 Doug in San Diego said:

Can you elaborate on the PCV valve set up

It sounds like this is my problem, because I removed all the old snorkle and now there is no vacuum on the oil vent.

What do I need to build this? Or what do I buy?

I don't think it is the rings, I did not line up the slots, and they are pretty damn new. (less than 200 miles)

Just tell me its cheap

Just go to any auto parts store and look at PCV valves. Find one that has hose fittings for both sides. Just make sure you install it so the flow goes the correct way and follow diagram that was provided and you'll be fine.

I don't have an explanation on why the crankcase does this as I really doubt it's the rings as suggested by some as my engine has very good compression. But installing a PCV valve and a vacuum source has fixed this problem for me.