PCV on 427

[Chuck]

I may add a PCV to our 427. The large vacuum port on the base of the carb is already in use. Would the threaded plug noted in the picture be an appropriate place to install a fitting to connect to the PCV valve? (Follow the blue tape). I am assuming that is in the manifold intake circuit.

[Jac Mac]

No, that is only servicing one runner to one cyl, PCV must go to carb base or spacer beneath in the plenum area, If you plumb it to one runner you will likely get oil fouling indications on the plug etc in that cyl.

[Chuck]

Thanks Jac Mac. That is what I was wondering about.

Question: Can I "T" the line that goes to the brake booster and feed the PVC hose to it? The brake booster has a check valve in the line.

Something tells me I need a separate port on the carb base or it may gum up the check valve eventually. Am I right?

[Randy V]

Yes - you can "T" that line without any drama - even in an engine that's an oil pumper.. Remember that it's a vacuum line and there will be nothing traveling "UP" that line to your booster or PCV - it's all coming toward the intake manifold itself..

That said - you *could* run your brake booster to the port that is over the single runner as that runner will see the same vacuum signal that the intake plenum sees. Although size of the port may come into play - I would think that at least a 1/2" pipe fitting would be as small as you'd really want to go with..

[Chuck]

Randy:

Good idea! Thanks.