What PCV system with 6-71?

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70Duster440

70Duster440

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Wondering wihat PCV setup you're using with 6-71. Breathers only? Check valve, catch can? Really don't want oily residue collecting in engine compartment.
 
I bought one made out of brass that has a 1 way check valve in it. On vac it send the fumes through the intake, on boost the check valve shuts it down so you don't pressurize your crankcase.

I have Breathers and this check valve is plumbed to the plenum after the throttle body engine side.

Quick opening brass check valves here... Just 0.3 PSI to crack it on VAC, on boost it will close like right now.

http://www.mcmaster.com/#standard-brass-check-valves/=hc53fz
 
Mad Dart said:
I bought one made out of brass that has a 1 way check valve in it. On vac it send the fumes through the intake, on boost the check valve shuts it down so you don't pressurize your crankcase.

I have Breathers and this check valve is plumbed to the plenum after the throttle body engine side.

Quick opening brass check valves here... Just 0.3 PSI to crack it on VAC, on boost it will close like right now.

http://www.mcmaster.com/#standard-brass-check-valves/=hc53fz
Click to expand...

Thanks for the link. So, essentially we're just adding a check valve where the PCV line would connect at the manifold (below the rotors). And make sure VC baffling isn't allowing oil vapors in to lean the mixture - right?
 
Yes, you also want to keep boost from entering the valve cover and pressurizing the crank case. So this check valve has 2 jobs instead of just 1 job.
 
I run a stock pcv fed from the carb adapter plate, that sees vac- never sees boost as its above the blower.
 
Mine is a little different cause it's Turbo, VAC is after the throttle plate. On boost with Turbo's the complete intake tract is pressurized on Boost, unlike a Blower, which is only after the Blades, above the blower your PCV would be fine. Sorry for the confusion.
 
There seems to be conflicting opinions on a PCV system with a blower. BDS and the Blower Shop both supposedly recommend against the traditional setup and suggest multiple breathers on the VC's. Their reasoning is it can suck oil in causing a lean condition.
 
70Duster440 said:
There seems to be conflicting opinions on a PCV system with a blower. BDS and the Blower Shop both supposedly recommend against the traditional setup and suggest multiple breathers on the VC's. Their reasoning is it can suck oil in causing a lean condition.
Click to expand...

That makes sense. During boost, thats the time when high crankcase pressure will be present from some blowby, is the time when PCV is needed. I do run a breather in one valve cover and a single PCV in the other valve cover. Without the breather, I was pushing out the intake china wall gaskets on a sb Mopar.
 
I want the benefits of a PCV without the mess of running only breathers - but also don't want to introduce oil vapor to the mix.

Plumbing either way should work as long as if it goes to manifold, there's a check valve. Maybe add an oil separator or insurance.
 
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