valve cover question

[wahlie]

so i pulled my valve covers off as i'm cleaning up my 350. I got the casting number behind the alternator and narrowed the motor down to an either 73 or 74 van/bus. My question on the valve covers.. The one had an oil filler cap and a pcv valve and the other just had an oil filler cap. Can I purchase a new set that only has the oil filler cap on 1 side and the 2nd valve will have the pcv valve?

thanks,
Chris

[GruntMoanCough]

Yes, the second filler is not neccessary. Someone put the wrong cover on.

[wahlie]

cool thanks!!!

[Longhorn Man]

I hope one of those caps is a vent.
You must have a vent on the opposing valve cover from the PCV valve.

[wahlie]

Here is a pict of what I currently have labeled. All of the edelbrock stuff that i've been looking at only has 2 holes. They look too small for oil caps though.

[piecesparts]

You can put a set of covers on that has a PCV valve hole (small one) in one cover and a filler hole (Larger one) on the other side that doubles as a vent for the PCV function. This vent can either be one that vents to the atmosphere around the valve cover (makes a mess on the covers) or it can be connected to the air cleaner to get a filtered air source from inside the cleaner. I normally choose to route my vent to the air cleaner to keep the engine cleaner. This can be done on any air cleaner, with some creativity.

[C20-67_N_MO]

Originally Posted by piecesparts

I normally choose to route my vent to the air cleaner to keep the engine cleaner. This can be done on any air cleaner, with some creativity.

I agree 100%!!!

This is by far the best and cleanest way to have a vent and not have a mess inside your engine bay.

Good luck.

[wahlie]

Right now the pcv valve hooks up to my carb.... is that what you guys mean by air cleaner since that is connected to the carb?

thanks,
Chris

[Longhorn Man]

no, they are talking about the vent on the other side from the PCV.

[piecesparts]

If you look at the two engines, you will see two sets of hoses or lines from the carb to the valve covers on each engine. The one on the passenger side of the engine is the vent from the valve cover to the bottom of the air cleaner (that is the air INTO the engine) The other one from the driver's side of the engine to the base of the carb is the PCV valve line, that is the air and gasses OUT of the engine and back into the combustion chamber area to be burned in the cylinders.

[ol'blu72]

Just a question. Does'nt routing the vent to the air cleaner and routing the vent to the carb achieve the same thing?

[C20-67_N_MO]

Originally Posted by ol'blu72

Just a question. Does'nt routing the vent to the air cleaner and routing the vent to the carb achieve the same thing?

No!

As Longhorn Man was saying one is strickly a Vent and the other one is attached to the PCV valve to be burnt in the combustion chamber.

[piecesparts]

Look at it this way, the line to the bottom of the carb has a negative pressure or a vacuum on it, caused by the cylinders sucking in air and fuel into the cylinders. The one to the air cleaner has a positive pressure to it, since it is connected to all of the free air space above the venturis in the carburetor. That is why the two lines are different. By running your PCV this way, you are sweeping the spent gasses and oil fumes from your engine's crankcase and keeping it from becoming pressurized and blowing oil out of the seals and gaskets. This makes your engine run with less resistance (windage) inside it.