I built my 383 in the spring, but now it likes to use oil, progressively worse, really pissing me off. I am not sure where its coming from. I know cylinders 4 and 5 are the culprits because the plugs certainly have oil on them. I changed the valve stem seals, still the same. On start up, it will leave a good blue cloud. The other time it uses, is when I roll it from first, hold the gear a bit, then step on it, I will smoke out who ever is behind me. If I do the same in third and punch it, I hardly notice any smoke. There are two things I can think of, either the valve guides are bad or broken and/or lined up oil rings. The heads I cheaped out on when I built it because I ran out of money, they are aluminum summit heads, I used hyper 10.7/1 pistons and moly rings. The PCV system is a breather cap on one end and the PCV valve connected to the carb on the other. I dont think its pulling that much oil through the PCV. Any insight is appreciated, thanks a bunch.

 

If you switched the heads side to side, #'s 4 & 5 would switch places.

Makes one wonder if there was a casting or machining problem on that intake port that is allowing oil from the lifter valley or rocker area into those cylinders.

Not familiar with those heads, but if the rocker stud hole extends into the intake port, and the stud threads weren't sealed, you can get oil into the port that way.

 

I didn't think about the studs. I don't remember if they did extend into the intake ports or not. I will have to check that out. Thanks for the info.