i have a 440 lsx motor with a catch can. the motor has about 600 miles on it
i just noticed when you take the hose out of the can it blows heavy smelly
smoke. if i am at a traffic light you will see smoke coming from the can.
any help thanxs

 

Does the car feel down on power? Any oil consumption?

 

no on both questions

 

Seems normal. All of my past forged motors huff a good amount of smoke when vacuum is removed from the crankcase. I always refer it to one or two cigarette's worth of smoke when burning. It's could be steam from the weather also.
If you have a huge cam with a pcv to catch-can, there may not be enough vacuum a idle to maintain negative crank case pressure, thus the smoke.

 

it is more like 20 cigs it pumps out hard and i dont think it was this bad before thanks cam 255/260 113 lsa @.50

 

how hard does it come out of the oil fill cap? when i busted ringlands on my stock ls1, it huffed and puffed like a chimney. I doubt that's your problem. Just referencing. Coolant in the oil will cause steam also. something to check.

 

it is like a chimney
but it is constant there is no water in the oil .it did backfire on the dyno
but the power was the same on the next pull

 

Unless you are running gapless rings a motor is gonna have blowby. Depending on how the ring gaps are setup for the motors purpose (nitrous,boost etc) and C.I. you could have more or less. This blowby HAS to escape the crankcase somehow. Most use the PCV system to evacuate these gasses out via a vaccume source. When you remove that vaccume source (taking the hose out of the can) it now evacuates on it's own (and you create a vaccume leak). Is your fresh air intake still thru the throttle body?

 

no it is plugged

 

does the crankcase then get's it's clean air supply?

 

I would guess you are running a breather in either valve cover. With the catch can hooked up there should be a constant vaccume signal via your fresh air intake.

 

driver side is hooked up to the pass side valve cover and then a hose off
to the catch can

 

Where is your fresh air source? There HAS to be a point where fresh air enters the crankcase. You stated you plugged the TB port wich is where the factory fresh air supply "was".

 

so should i open up the tb port

 

Do you understand how the PCV system operates? Please dont take that question the wrong way I am not being an *** here. It is actually fairly simple when it's explained correctly. I dont wanna explain it if your aware of how it works. If not just say so and you'll get to learn something.

 

i dont know want you mean

 

what he means is you need fresh air to to enter the crank case in some way or another. the PCV system draws fresh air (from outside the enigine) into the engine. if you dont have this then your PCV system is probably not circulating properly and the smoke is building up inside the crank case. you either need a breather filter in place of the oil cap, or the port on your TB needs to be connected to the valve cover


"blowby" taken from wiki.
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". [6] 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. [7] 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. In a non-turbo engine, the intake manifold is at a lower pressure than the crankcase, providing the suction to keep the ventilation system going.

here is something to help explain what PCV is and what it is meant to do http://en.wikipedia.org/wiki/PCV_valve

 

which valve cover

 

the front of your passenger side valve cover, where the oil filler cap should be is where you put a breather filter. OR at the top of the valve cover would be a barbed fitting and that is where there should be a hose running from that to your TB.....

can you get us a pic of your engine bay?

here is a pic of the breather in the oil fill cap:



here is a pic of how you shoudl have the line running from the front of the cover from the factory.

 

Here is a real basic idea of things (pay no attention to the picture below just yet). If you had a hole in each valve cover (hypothetical like an oil fill hole on both sides) and attached a shop vac to the hole on the passenger side and turned it on then walked to the drivers side and placed your hand over the open hole you would feel air getting drawn in. The shop vac would suck air up out of the crankcase cavity thru the pushrod and oil return holes in the passenger head this air is replaced with the incoming air from the open hole in the drivers side valvecover. This is how the system "basically" works in theory. The difference is your intake does the job of the Shop Vac as that is the vaccume source. Here is a diagram below of a stock LS is setup.

I illustrate the air flow direction with arrows the green line is air being drawn (sucked) out of the motor the blue is fresh air being sucked into the motor. Important note the port on the throttle body is simply a bypass hole that lets air enter the front of it and exit on the passenger side. The reason for air having to pass thru the throttle body is because it gets filtered thru the stock airbox thats in front of it and the MAF can meter it. After it exits the throttle body it enters the front port on the passenger valve cover this portion in blue represents the "open hole" portion of the hypothetical scenario I started this post with above. The green line represents the Shop Vachose and the intake manifold itself is the vaccume.
Now you can cap off the throttle body like you did thats fine thus eliminating the blue line but now the vaccume has no source to pull in fresh air as I would think you capped the front valve cover port as well. You need a new hole for fresh air to be pulled in from I personally put a breather in my oilcap. Now air gets drawn in thru that and this fresh air does need to be filtered as it will go thru the motor and eventually into the cylinders.

The green lines air after coming out of the motor is very hot and contains oil vapors/mist. This is where the catch can comes into the picture. The catch can is inserted into the green run and acts like a filter in it's own right removing the oil that is in that hot air and collecting it before it goes in the intake manifold to be reburned. The actual reason for the PCV is to remove the blowby gasses from the crank case. A small amount of the engine intake charge escapes around the pistons and slips into the crankcase below it. These build up and pressurize the crankcase if they are trapped like in your case. When you remove the can hose you are providing a way for it to escape and you are seeing this with the smoke. I hope this helps you out a lil bit and anybody feel free to add anything I overlooked or may be misleading on. I'm far from an expert on this and did not really have a grasp on this until recently myself.