PVC not necessary...do this

Roger, the hole in your exhaust that you've fed the crank case vent into. Disconnect at this point and put your finger over both holes, the one in the exhaust and the breather pipe end, tell me the pressure at these points at idle, mid rage and high rpm. Apart from having a burnt finger, I'm purty damn sure the higher pressure will be the exhaust. Which way do you think the gases will travel? It won't wear out, I have to agree, but it won't work I'm sure. Like I said the proper evac systems rely on the scavenging action of high speed exhaust gas, they don't work at street rpm levels. And they must have a check valve of sorts, other wise you'll fill the crank case with exhaust gas, and only when/if you get the exhaust speed up to a point where it will pull from the breather pipe, will it have any chance of pulling the crank case gas out.
Think your barking up the wrong tree here. If you find it doesn't have the negative effects I talk of please let us know.
Martin.
 
Re: PCV not necessary...do this

Here is what I believe. There will be pressure from the exhaust to go out the tailpipe and there will be pressure from the engine to release out the pex tube. They will co-mingle and gleefully travel along until they release into the clean California air.
 

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Re: PCV not necessary...do this

Roger/Sacramento said:
Here is what I believe. There will be pressure from the exhaust to go out the tailpipe and there will be pressure from the engine to release out the pex tube. They will co-mingle and gleefully travel along until they release into the clean California air.
Click to expand...

If you do install a tube in the tailpipe as you have illustrated, before hooking it up to the engine a way to check your theory is to connect a water column tube to see if in fact there is a vacuum.

 
I think the exhaust tube would have to be dimpled, in order to create a venturi effect?...or would would the tube just have to be installed at a proper angle? In order to draw?
 
Re: PCV not necessary...do this

A properly running engine (without much blowby) does not have pressure in the crankcase seeking an escape. This is why PCV systems rely on engine vacuum to pull the vapors out and also why draft tube systems rely on road draft to pull as well. Crankcase pressure is generally neutral, except that heat will cause the air to expand and seek an escape. Once the engine is hot and it escapes, the pressure is equalized and generally neutral again, except for blowby which is only significant if your engine happens to need a rebuild.

I think your device will only succeed in filling the crankcase with exhaust. If it does work, you'll be filling your exhaust with oil and water vapor.


Interesting concept, but perhaps an easier method is to buy a pulse fuel pump that allows fuel to pass through and do a typical PCV conversion.
 
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As mentioned before, the draw needs to come from where the road draft tube is/was. There are air flow schematics that clearly show this. While I can see your point in scavenging, the whole purpose of a PCV is "positive crankcase ventilation".

IMHO, it is one of the only smog designs implemented before year 2000 that actually has a positive and useful effect on an internal combustion engine. It is certainly one of the best ideas. By actively sucking crankcase gases out of the engine, it not only actively keeps those gases and moisture out of the engine, it reduces or removes positive crankcase pressures, reducing oil seepage.
 
Work or not / I like the thought process / That is how things use to get solved
Talking over the pros & cons of something / sometimes it will let you see a problem that you may have over looked.
 
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