Valve cover ventilation

benitouk · 03-07-2015, 03:01 PM

Hi guys! I Just found out that my scooter valve cover ventilation nipple has no hose / oil catcher attached to it, meaning that the vapors and oil are spilling directly on the ground....

I was doing some research because I'm not sure what I should put here. I have seen oil catchers both with / without filters attached, what's the difference? If I completely want to upgrade the oil system, should I also include an oil cooler?

Any help is appreciated!

rks · 03-07-2015, 04:46 PM

I guess it's a matter of personal taste. I routed my crankcase breather tube into what is called a catch can...didn't want stuff dripping all over. Did this when I replaced the factory air box with a K&N cone filter.

Here is a link to a thread I started a while back about this....there are pictures linked to that thread, with a short caption under each. Also a couple of pics in my profile...click on my user name....and then on album titled "My Stuff"

http://scootdawg.net/showthread.php?t=54327

An oil cooler would be nice...both of my BMW's have them, but don't know it the tiny, weak oil pumps in our scooters could handle feeding one. I've seen kits offered, and heard of people buying them....but never read a follow up story of how things worked out.

rks · 03-07-2015, 04:54 PM

I just noticed you are new to this forum......and I didn't even welcome you....my bad

Welcome to the forum benitouk, glad to have you...

bull · 03-07-2015, 07:20 PM

As rks suggests the crankcase ventilation system hose routing after new scooter delivery is a matter of personal taste.

The manfacturers connect the hose to 2 different places (PS & Tao Tao) I have seen. Both on older scooters attach them to the air box inlet tube. On newer scooters they are attached to the carb air inlet tube.

I have tested it in both places on new and old scooters vs a liquid vapor separator (catch can) vs venting to atmosphere.

I personally do not like aiding in increasing the air pollution any more than absolutely necessary, so no atmosphere venting for me. The catch can (liquid vapor separator) is a proven technology but does not provide enough benefit IMO. Auto draining / capturing & returning oil, provide for recycling of blowby gases is just not sufficient.

Venting to the air box intake hose, does deposit some byproducts in the foam air filter but does not increase the service interval significantly.

Venting to the carb air inlet tube does allow some deposits to build up on the carb venturi and in the air passages rather quickly. This can become a problem on engines with excessive blowby gases and I don't recommend or use this. In fact I reroute the new scooters to the air box inlet tube- least amount of harm to both the atmosphere and the scooter.

benitouk · 03-07-2015, 11:59 PM

These are the 2 different systems I found.

The first one is connected from the crankcase vent nipple to the 'can', which has an air filter, and then connected back to the oil tank.

The second one, is just a regular oil catch can that I have no idea where to plug...

rks · 03-08-2015, 08:59 AM

I have a much larger, more sophisticated, two chamber, billet aluminum catch can on my Camaro, that is plumbed back into the intake manifold. Intake valves become badly coked, very quickly on these direct injection engines, without a good catch can.

Thought it might be a bit of over kill to use one like that on my little plastic scooter....so made one from a plastic pill bottle.

Whatever you decide to do....I might suggest you don't let the liquids drain back into your crankcase. If you could smell the stuff I've collected, you'd probably understand why I say that. Acids and who knows what do form in these condensed vapors..... some have said they don't see a problem with it, because of the small quantity....

I wouldn't put that stuff back into my oil....anymore than I would pour a cap full of vinegar, or bleach in it.

bull · 03-08-2015, 09:13 AM

IMO, both of those are seriously flawed in design and function.

Both vent to atmosphere rather than recycling the heated vapors back into the engine. Both would flow "oil" back into the engine but through different areas. eg: the top (purple color) flows into the oil fill / dipstick hole.

A better design would be back into the cam cover when enough oil is accumulated using only a single hose but with internal storage / release valving, plus a tube connected to either of the factory vent hose ports for immediate recycling of the vapors.

If you insist on having one of those, then get rks to share his engineering and design for his, at least then you will have less cost in it and learn something about scooter maintenance and engineering.

benitouk · 03-11-2015, 06:47 PM

Thanks for your help guys

03-07-2015, 04:46 PM	#2
rks Join Date: Dec 2013 Location: Western New York Posts: 454	I guess it's a matter of personal taste. I routed my crankcase breather tube into what is called a catch can...didn't want stuff dripping all over. Did this when I replaced the factory air box with a K&N cone filter. Here is a link to a thread I started a while back about this....there are pictures linked to that thread, with a short caption under each. Also a couple of pics in my profile...click on my user name....and then on album titled "My Stuff" http://scootdawg.net/showthread.php?t=54327 An oil cooler would be nice...both of my BMW's have them, but don't know it the tiny, weak oil pumps in our scooters could handle feeding one. I've seen kits offered, and heard of people buying them....but never read a follow up story of how things worked out. __________________ 2011 Jonway 150cc..16,109 breakdown free miles, and counting
	0

03-08-2015, 08:59 AM	#6
rks Join Date: Dec 2013 Location: Western New York Posts: 454	I have a much larger, more sophisticated, two chamber, billet aluminum catch can on my Camaro, that is plumbed back into the intake manifold. Intake valves become badly coked, very quickly on these direct injection engines, without a good catch can. Thought it might be a bit of over kill to use one like that on my little plastic scooter....so made one from a plastic pill bottle. Whatever you decide to do....I might suggest you don't let the liquids drain back into your crankcase. If you could smell the stuff I've collected, you'd probably understand why I say that. Acids and who knows what do form in these condensed vapors..... some have said they don't see a problem with it, because of the small quantity.... I wouldn't put that stuff back into my oil....anymore than I would pour a cap full of vinegar, or bleach in it. __________________ 2011 Jonway 150cc..16,109 breakdown free miles, and counting
	0

03-07-2015, 07:20 PM	#4
bull Join Date: Feb 2015 Posts: 257	As rks suggests the crankcase ventilation system hose routing after new scooter delivery is a matter of personal taste. The manfacturers connect the hose to 2 different places (PS & Tao Tao) I have seen. Both on older scooters attach them to the air box inlet tube. On newer scooters they are attached to the carb air inlet tube. I have tested it in both places on new and old scooters vs a liquid vapor separator (catch can) vs venting to atmosphere. I personally do not like aiding in increasing the air pollution any more than absolutely necessary, so no atmosphere venting for me. The catch can (liquid vapor separator) is a proven technology but does not provide enough benefit IMO. Auto draining / capturing & returning oil, provide for recycling of blowby gases is just not sufficient. Venting to the air box intake hose, does deposit some byproducts in the foam air filter but does not increase the service interval significantly. Venting to the carb air inlet tube does allow some deposits to build up on the carb venturi and in the air passages rather quickly. This can become a problem on engines with excessive blowby gases and I don't recommend or use this. In fact I reroute the new scooters to the air box inlet tube- least amount of harm to both the atmosphere and the scooter.
	0

03-08-2015, 09:13 AM	#7
bull Join Date: Feb 2015 Posts: 257	IMO, both of those are seriously flawed in design and function. Both vent to atmosphere rather than recycling the heated vapors back into the engine. Both would flow "oil" back into the engine but through different areas. eg: the top (purple color) flows into the oil fill / dipstick hole. A better design would be back into the cam cover when enough oil is accumulated using only a single hose but with internal storage / release valving, plus a tube connected to either of the factory vent hose ports for immediate recycling of the vapors. If you insist on having one of those, then get rks to share his engineering and design for his, at least then you will have less cost in it and learn something about scooter maintenance and engineering.
	0

03-11-2015, 06:47 PM	#8
benitouk Join Date: Mar 2015 Posts: 6	Thanks for your help guys
	0