Adding PCV valve to 351W - Side Effects?

[cobrajeff]

The road draft tube plugged into a valve cover breather hole at the top, and dropped down beside the engine. The lower end was cut-off at an angle, so that air running by it under the car would "pull" the vapors out through the open tube.
This is exactly the same set-up as you would find on many early 64-64 1/2 289 engines (before PCV valves).

Regards,

Jeff

[Bob In Ct]

So what is the answer to my original question? Do I need to rejet or adjust the timing?

Just for the record a PCV valve is not a pressure reducer. it's a ventilator. Breathers will allow any excess gas to escape!

Bob

[Jack21]

Your timing should be unaffected by adding a PCV.

Your primary side jetting may need to be increased a size or two because you're adding additional air with the PCV. Idle mixture may need resetting. Secondaries should not need any changes as PCV adds little, if any air under low vacuum, such as when secondaries are open.

If you don't re-jet, and engine starts pinging, re-jet carb before retarding timing.