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I have a small block 350 chevy and i was just wondering if i should run a pcv or if i should just use breathers. Are there advantages to either? Also if i run a pcv are they all the same or is there a certain one i should use? thanks in advance.

Thanks,
Matt
 

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you know i have been looking into this for a while. i like to runa pvc valve. it is a can bring the crankcase into a vacuum,adding power. it helps oil distribution.cleaner exhaust and engine bay. i dont think there are any negtives other than cost ,one more thing to replace.i guess you could argue against rebreathing those vapors,but i cant image why?
 

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They don't really put any vacuum in the crankcase at full thottle, because there is no (or almost no) vac at full throttle, so they probably don't increase max power.

At a light cruise though, the PCV valve could very well be open and helping your rings seal better due to vac in the crankcase.... theoretically....

I like to run them, though, except on an all-out race engine that would never even produce enough vacuum to open them. But they help keep your crankcase clean by sucking out oil vapors and condensation. This keeps crap out of your oil and deters sludge buildup. And they don't really hurt anything; you just have to richen the idle mixture a bit. It's a win-win.
 

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PCV

Doc here :pimp:

A properly Installed, Maintained PCV valve will add to your engine! (Not performance wise, but in other ways)

First it will help to reduce that Blow~by your probably seeing now at idle...(white smoke out the breather holes)

It will keep your engine clean (er) inside and out and under carriage too. Blow by in road draft tubes also bring with it oil...and tosses it overboard, and all over your engine. By installing a PCV, and blocking the road draft, this condition will stop.

You may have to install Baffled Valve covers if you don't already have them, and a Positive Vented oil filler Cap to keep from over pressurizing the crankcase...

The ONLY Down-shot to a PCV valve, is occasionally The get dirty and stuck open, (lack of maintenance) and will Suck oil into the induction system and make it smoke and run like Crap in a can...

BUT you would have to avoid servicing it for like 4 tune~ups before this should occur...

Clean it with Carb Cleaner at each tune up and make sure it rattles when you shake it, and the cleaner is clean coming out...and you'll never have the problem.

Install it, and "Gunk" the engine..you'll be glad you did..and you'll note it stays cleaner longer!

Doc :pimp:
 

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When I was into building performance Ferrari motors, I met a man who invented a new style PCV valve. Originally it was designed for motorcycle racing and then it found its way into Ferrari race motors. It doesnt have any moving parts, and is supposed to never need replacement since there are no parts to wear out. He gave me two to try out on my Ferrari but I never did, but I did last week put one on my 408windsor motor now. I will try to get some photos of it, and find the patent number, at one time I remember I looked it up and found the designs online.


Ben


Found it http://patft.uspto.gov/netahtml/search-bool.html

When you go there search for this number 5967178

Then you can goto Images and see the photos of how it works.
 
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