Catch me if you CAN.

[swheels]

For some reason i'm getting a lot of pressure build up in the crankcase.Which is causing the oil to escape in the form of smoke.(blue smoke from the vent hose)Will after awhile it would build up on the lower fairings.Then drip in front of the rear tire.LOL Long story short i used a small wd-40 spray can to use as an oil catch can.I dressed it all up with some graphics.I thought it was pretty cool.

[schofell84]

build a pcv system

[swheels]

build a pcv systemThat's sorta how this one is setup.The brass tube runs all the way to back of the can.I drill 4 holes in the brass tube.The drilled a small in the can itself on the opposite side more towards the top.So the pressure can still escape but still keep any oil trapped inside.

[schofell84]

drill a hole in the rubber intake boot and run a hose to it from the crankcase with a pcv valve from an auto store in it. it cools the combustion temperature a bit.

[swheels]

drill a hole in the rubber intake boot and run a hose to it from the crankcase with a pcv valve from an auto store in it. it cools the combustion temperature a bit.Oh ok i get what your sayin.I was thinking more along the lines of how the pcv valve lets the crank case breathe while still trapping the oil.

[rene13]

They are dip sticks but they measure celius or the trailtech computers that have a speedo,tach,oil temp sensor.

www.trailtech.net (http://www.trailtech.net)

[The Nutty Professor]

OK having a CRS (Can't Remember Shizzle) moment. Isn't a certain amount of crankcase pressure desireable? How much is too much and how much is too little? Is there a way to measure crankcase pressure like we can measure compression? I know compression testing is almost a static test and crankcase testing would be very dynamic, but there has to be lost horses there somewhere?dunno

[schofell84]

I've never heard of someone measuring crankcase gas temperature ... if you were talking oil temp you could probably just tap a hole for a sending unit and do it that way.

excess pressure in the crankcase would possibly help ring sealing? I'm not sure nuttay, thats a damn good question. i know too much is bad, but too little might be bad also. single cylinder engines produce some wicked pressures in the crankcase because they don't have another cylinder to equal the pressures out with. older engines used large crankcase volumes to help solve the problem(unless your harley davidson and your still not even in the 20th century), but a crankcase vent usually solves the problem. there isnt alot of solutions due to the engine design.

[rene13]

Air ventilation
During normal operation, a small amount of unburned fuel and exhaust gases escape around the piston rings and enter the crankcase, referred to as "blow-by". If these gases remained in the crankcase and condensed, the oil would become more diluted over time, decreasing its ability to lubricate. Condensed water would also cause parts of the engine to rust. To counter this, a crankcase ventilation system exists to draw fresh air in from the air filter and expel the gases out the PCV valve into the intake manifold. The intake manifold is at a lower pressure than the crankcase, providing the suction to keep the ventilation system going.

If an engine is damaged or enters old age, gaps can form between the cylinder walls and pistons, resulting in larger amounts of blow-by than the crankcase ventilation system can handle. The gaps cause power loss, and ultimately mean that the engine needs to be rebuilt or replaced. Symptoms of excessive blow-by include oil being pushed up into the air filter, out the dipstick, or out the PCV valve.

[Blitz$M.Inc.$]

S, i have had issues where oil was comming out of the case vent
in normal circumstances you wil not get lots of oil out of the vent tube like you describe
when i had it comming out like you i had a ring/compression loss blowby like a mother
a few times it started slow like yours is then it gets real bad when the rings get closer to the gaps
are you haveing ANY run issues, your motor should fly
the last time i had oil out the vent was when my last 146 kit ate it
since then i rigged up a airplane vodka bottle for a catch and i have 2 drops in a month time

[swheels]

What shot of vodka.LOL The motor is running like a beast......Here's what i was thinking.Because the engine crankcases was originally designed for the smaller cc's.I was thinking that the more you go up in cc's and the crankcase size remains the same.That the crankcase can't handle the amount of turbulance and the slightest amount of blow by.Generated by the larger cylinder and piston.
My motor still have gobbs of compression.But i also vented the head and it seems to help a great deal.

[schofell84]

another reason to vent the crankcase is to relieve the pressure created by the piston moving up and down rapidly. if the pressure is allowed to change with piston movement the rings will seal better and you will get better performance and life. oh your oil is gonna last longer too. meow.

think of it this way. when the piston is going up in the cylinder it creates a vacuum (the area in the crankcase is expanding)and tries to draw combustion gas by the rings. the vacuum also slows the piston movement, making it accelerate slower. (wasting horsepower)

when the piston is coming down it is trying to compress the atmosphere in the crankcase, which leads to blowby. (and slowing engine acceleration(horsepower))

[redryderaus]

Excess pressure in the crankcase could be a sign of damaged rings and/or bore allowing more combustion pressure to escape past the piston. Increasing cylinder volume will not cause it as the positive pressure (piston coming down) is balanced out by negative pressure (piston going up). I'd also check your breather isn't partially blocked.

Cheers,

red

[swheels]

Well Red if this weekend weather is good.I'm gonna romp on that motor until i feel i've got my money's worth.LOL Or it blows up.pimp1

[Blitz$M.Inc.$]

ok well keep an eye on your oil level

[X7rocks]

GPX motors and other motors build up so much pressure there just forced to put out oil from there
there has ben a mod i saw somewhere that doesnt allow it to do so
but some problems do occur by closeing off that case vent such as it being clocked it would actually blow the oil through the exhuast like something that happend at sandy hook cough cough mybusa
it was weird aswell...he had oil flying out his exhuast then BOW oil just came pouring out the dipstick cuase the pressure just builded up