Thread: PCV problem

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I changed carb from a 600 cfm Edelbrock Proformer to a 650 Edelbrock Thunder series on my 350 sbc. Everything was working fine until the engine started smoking. Upon inspection I found oil going into the rear vacuum port of the carb from the PVC valve. The valve was what came in a Billet Specialties PVC unit. I unhooked the pvc valve, pluged the port on the carb and the smoking subsided. I then installed a new pcv from an early 70's sbc in the billet housing and reconnected to the carb the problem got worse. disconcted, pluged and ran again. Smoking stopped but the valve cover started leaking around the gasket on the lower side, possibly from lack of venting on that cover. Where am I going wrong, Is there a special pcv valve I need or is this symptoms of a larger problem.

350
Flat top 4 relief pistons
Performer intake
560 lift cam 290 advertised duration 112 deg overlap
62cc double hump heads 2.02 int 1.5 ex. roller rockers
Had 1,200 miles on engine before carb change.
Baffles in covers
Open system 1 pcv 1 breather
15 inches Hg

Thanks in advance
Greg

It sounds like you're sucking oil directly into the intake. Need to have some good "cross flow" on the PCV and the vent to provide plenty of make up air so that the PCV isn't sucking oil vapor only. I have use the setup below on lots of engines with no issues. It requires the PCV on one side and a vent on the other. If your air cleaner isn't set up for a vent, you can use a push in vented cap (Mr Gasket Moroso, etc).

Good Luck,
Glenn

Sorry. Forgot to mention the breather on the other side.

Open system 1 vent cap 1 pcv cap

I would switch the PVC vacuum to the the passenger side from port on the carb

http://www.edelbrock.com/automotive_...ers_manual.pdf