Crankcase evacuation valve

[Kenny]

  Okay, here is my best explanation; When the piston comes to bottom dead center, the crankcase will be at max pressure. This pressure bleeds out through the valve. The valve will slam shut, trapping vacuum as the piston goes back up. This stabilizes the rings and improves seal. The valve is extremely sensitive and durable. I have a guy build these for me that actually has a patent on them. They withstand nitromethane and methanol. I just happened to be in the right place, at the right time when I found these badboys :grin_nod:

[socalrappy700]

Thanks for the pics and write up Kenny.  You have been helpful as always.

[Colorado700R]

Money enroute for Dylthiium Crystals  I mean cam cover evacuator valve 

:grin_nod:

[ThisGuyAlex]

so it's a pcv valve from a car basically?

[Kenny]

so it's a pcv valve from a car basically?

Not even close

[Krandall]

question..

when the valve releases the pressure while the piston is at bottom and the piston goes back up. How does the crank case get more air? Wouldn't the piston on the way back up try to pull air in? If it's not coming through the valve, is it pulling it through the rings?

Or am I missing something?

[preddy08]

question..

when the valve releases the pressure while the piston is at bottom and the piston goes back up. How does the crank case get more air? Wouldn't the piston on the way back up try to pull air in? If it's not coming through the valve, is it pulling it through the rings?

Or am I missing something?

The crankcase does'nt get more air, thats what makes it work. When the piston goes up in its stroke it creates a vacume and forces the rings outward for a more positive seal.

[Krandall]

question..

when the valve releases the pressure while the piston is at bottom and the piston goes back up. How does the crank case get more air? Wouldn't the piston on the way back up try to pull air in? If it's not coming through the valve, is it pulling it through the rings?

Or am I missing something?

The crankcase does'nt get more air, thats what makes it work. When the piston goes up in its stroke it creates a vacume and forces the rings outward for a more positive seal.

So how does more air get in the crank? seepage past the rings? This thing obviously lets out more air than just 1 puff right?
Sorry if I'm coming across as a noob. I'm learning

[preddy08]

question..

when the valve releases the pressure while the piston is at bottom and the piston goes back up. How does the crank case get more air? Wouldn't the piston on the way back up try to pull air in? If it's not coming through the valve, is it pulling it through the rings?

Or am I missing something?

The crankcase does'nt get more air, thats what makes it work. When the piston goes up in its stroke it creates a vacume and forces the rings outward for a more positive seal.

So how does more air get in the crank? seepage past the rings? This thing obviously lets out more air than just 1 puff right?
Sorry if I'm coming across as a noob. I'm learning

Thats the beauty of this valve, is that there is NO "air" in the crankcase on an upward stroke.

[Krandall]

question..

when the valve releases the pressure while the piston is at bottom and the piston goes back up. How does the crank case get more air? Wouldn't the piston on the way back up try to pull air in? If it's not coming through the valve, is it pulling it through the rings?

Or am I missing something?

The crankcase does'nt get more air, thats what makes it work. When the piston goes up in its stroke it creates a vacume and forces the rings outward for a more positive seal.

So how does more air get in the crank? seepage past the rings? This thing obviously lets out more air than just 1 puff right?
Sorry if I'm coming across as a noob. I'm learning

Thats the beauty of this valve, is that there is NO "air" in the crankcase on an upward stroke.

I get that part
Why not just warm up the motor, move the piston to where it's all the way down (farthest it can go down) and then seal the crank exhaust hole?

[preddy08]

question..

when the valve releases the pressure while the piston is at bottom and the piston goes back up. How does the crank case get more air? Wouldn't the piston on the way back up try to pull air in? If it's not coming through the valve, is it pulling it through the rings?

Or am I missing something?

The crankcase does'nt get more air, thats what makes it work. When the piston goes up in its stroke it creates a vacume and forces the rings outward for a more positive seal.

So how does more air get in the crank? seepage past the rings? This thing obviously lets out more air than just 1 puff right?
Sorry if I'm coming across as a noob. I'm learning

Thats the beauty of this valve, is that there is NO "air" in the crankcase on an upward stroke.

I get that part
Why not just warm up the motor, move the piston to where it's all the way down (farthest it can go down) and then seal the crank exhaust hole?

That is kinda what its doing, but its doing it every revolution. Air will bleed off from the rings and from other misc area. So if you do it once it may last 30 seconds, this valve does it every storke.

[Krandall]

I gotcha. It sorta makes sense.. It makes the most sense on the up stroke creating the vaccum making a better seal. But what's wrong with just letting it breathe like it is set up stock?  I mean sure you don't get the vaccum, but it'd be letting out the pressure just the same correct?

[preddy08]

I gotcha. It sorta makes sense.. It makes the most sense on the up stroke creating the vaccum making a better seal. But what's wrong with just letting it breathe like it is set up stock?  I mean sure you don't get the vaccum, but it'd be letting out the pressure just the same correct?

Someone eles said expained it as if you were to put a brick and a feather in a jar and suck all the air out of it. They would both fall at the same rate. Its all about resistance.

As it is set up stock, it sucks and blows with every stroke get your mind out of the gutter, that is the best way to describe it.

[Krandall]

hmm, wouldn't there be more resistance though with the valve then? because with the piston going up, it's creating a vacuum which would create more resistance on the piston moving upward correct?

[preddy08]

hmm, wouldn't there be more resistance though with the valve then? because with the piston going up, it's creating a vacuum which would create more resistance on the piston moving upward correct?

Correct, but the vacum created is GREATLY overcame by the force of the motor.