Is it important to have a PCV valve connected and operating on any engine?
I don't have a vacuum line from the back of the carb. to the PCV valve. Is that hurting anything, especially performance?

 

It will not hurt anything directly... The PCV valve (crank case ventilation) helps preserve things such as your rings.. I have heard that they also help with the life of valves... I would connect it if i were you but it will not necisarily hurt performance just help with engine life.. The PCV valve is pretty much the only good "smog" mechinism that helped do anything...

 

are you blocking the port completely off or just not attaching it to anything? If you plug it, you could cause leaks and piston blow-by. Try holding your breath and then pushing the air out of your lungs while you keep your mouth shut and nose pinched. Same thing at high RPM for an engine without some sort of vent on the Valve cover.

 

You need to have at least a vent of some sort or you will blow out seals and gaskets. Also, without a PCV there is no way for condensation build up to escape. When you start a cold engine, condesation forms and is burned off while running. Condensation needs to go off as steam and the steam escapes via a vent (blow-by tube) or pcv. PCV is much more effective and will reduce sludge buildup in the motor. If you want your motor to last make sure the PCV valve is operational.

 

you really need to get a carb spacer with the built in nipple for connecting the PCV hose to it so the system can function like it's supposed to. all engines have some blow by, combustion gases that get by the rings, that build up pressure in the crankcase and the PCV system vents these gases back into the intake so that the pressure in the crankcase won't blow out gaskets and seals causing oil leaks. the system works by drawing in filtered air via a vent hose to one of the valve covers and then the PCV lets some of this air plus the blow by gases back into the intake to be burned up. if you don't run the PCV, then the pressure will blow oil vapors out of the valve cover vents if you have one and make a mess of the top of the engine. if you don't have any vents, then the pressure can build and blow out gaskets on the valve covers, oil pan or crankshaft seals, also making a mess. you can connect the PCV to a fitting in the intake manfold but it needs to be a large one to flow enough gas to work properly.