Run A PCV Valve Or Not?

[CryptoDude]

Ok, so for no other reason then simplicity sake, I want to clean up the valve cover. I am going to run a vent filter on the back nipple coming off the valve cover and am wondering if anyone’s just pulled the pcv valve and plugged it with a pipe plug. Does this engine need two places to vent the crankcase pressure??

The reason behind this is to get rid of 2 hoses, one mechanical component (pcv valve), and help keep the carburetor cleaner inside.

Thoughts?

[SubGothius]

I don't see eliminating it as much of an advantage, if any. The valve itself is pretty simple, not especially trouble-prone, and trivial to clean out or replace if needed.

It's basically just a two-way spring-loaded check valve to prevent: 1) crankcase gases diluting the intake charge under high vacuum (e.g. at idle), and 2) an intake backfire flame from propagating back into the rocker cover and crankcase. Otherwise, it allows those gases to be vacuumed into the intake under the carburetor, so it doesn't really foul up the carb either.

With the PCV valve removed and plugged, all your crankcase blow-by would go out the breather nipple at the back of the valve cover, which you propose to cap with a breather filter, and which may not be big enough to handle that gas volume/pressure by itself at all times. All those stinky and toxic gases would then vent to the ambient air, and your HVAC intake is right behind the hood there, so those gases would slowly poison you as you drive.

However, the main function of the breather is to provide an intake for fresh air to replace what the PCV system is vacuuming out. Ideally, that breather barb should feed a hose to the after-filter side of your air cleaner housing (most aftermarket housings provide a barb for this), or otherwise I'd suggest a Spectre #3995 breather filter with stainless mesh media:
https://www.spectreperformance.com/3995-breather-filter

[charger_john]

I agree with Gothius’s remarks and will also add this: the slight crankcase vacuum created by the PCV can help ward off oil leaks.

[CryptoDude]

Right, the only “advantage” I’m looking for is to simplify the setup. I ran this type of setup on my cammed, ported, megasquirted 22re with zero issues, I wasn’t the first person to run it like that though. I couldn’t find anyone on this forum who’d ran their truck this way so I may be the guinea pig.

I suppose if the 1/2” nipple at the back of the valve cover can’t vent gases from a 2.6L then I could always put a 90 degree fitting on the front of the valve cover and put a breather on it too, but I really don’t think that’s necessary. All that should be coming from the breather is oil vapor, no worse than an oil leak on your exhaust. An engine that creates so much crankcase vapor that it could kill you from toxic vapors should probably be rebuilt.

I forgot that a carburetor sprays fuel that cleans the inside of the intake/carburetor somewhat as it travels to the cylinder, much different than an port injection engine…this is the first carbed vehicle I’ve ever owned. Once I can get rid of the ridiculous amount of vacuum lines, I’ll be feeling much better about it.

Thanks for the link to that breather filter btw!

[SubGothius]

Swapping a Weber carb in place or the stock Mikuni carb and its feedback control box will eliminate most of the vac lines.

I'd recommend removing the carb and control box (mounted on the driver's inner fender) together along with all vac lines connected to/between them. That'll eliminate most of the rats' nest.