PCV setup - need the info!

moonenn3186

Founding Member
Jan 9, 2002
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Dubuque, Iowa
I am just a little confused.

I recently built a 351w (see signature) and was told that if I don't set up the PCV correctly, I will develop blowby - and I can already tell the rings are loosing seat.

However, I was told it is not to late . . .

I had custom valve covers welded up to clear the rocker assembly and look cool - I have a PCV push in breather on the passenger side valve cover installed with the hose into a stock 85 4v air cleaner (carbed car). The other valve cover is sealed. Do I need a breather over there? Can someone explain the basic principles here? Unlike the EFI 302 intake there is no provision for a PCV valve on the 351w RPM intake.

Thanks in advance
 
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You dont NEED a PCV valve going to the breather/intake.

All motors will have a certain amount of blow by, any increase is mostly caused by wear.

Race cars use crankcase evacuator kits which use the exhaust to actually create a vacuum at WOT which does help the rings seat better.

but since factory cars lose vacuum at WOT, there is none for the crankcase and the blowby simply gets pushed into the intake/breather. They used to simply vent this back in the 50s, EPA wanted this ran back into the motor even though it does not combust and causes some pretty nasty buildup in the intake over time.

If you have emissions inspections you may want to run another PCV valve in the other breather, this will help the breathing.