valve seal problems

I have recently built a 350 chevy, I switched to roller rockers, then my engine started smoking, badly. I have found the guide seals on the exhaust valves are coming up against the retainers, switched out heads to performance heads, same problem. Switched back to stock rockers, same problem. any suggestions??

What is your cam lift and rocker arm ratio? It sounds to me like something is amiss in that area.

i kinda got the same problem, i put in new valve springs and cam and lifters and push rods and i used the compressors that screw onto the rocker stud and push the valve springs down with a lever style fork. it worked well but after that i was getting alot of crankcase fumes through the breathers so i put in a pcv and now it comes out the exhaust. kinda sounds similar to your problem, i was thinking i mighta messed up a valve seal or something and im getting some blowby fumes into the valve covers???? i dunno. but for you have you tried replacing the valve seals, and are they the umbrella type or the o ring type? if they are o ring ones switch to umbrella ones and see what happens. some oil might be getting sucked by the valve

ok here are the total engine specs. chevy 350 from '77 camaro, bored .040 over, flat top hypereatic pistons, moly rings, cam specs 445/455 270/290. roller 1.6 rockers, stainless steel valves, 3 angle valve job, edelbrock performer2 intake, edelbrock 750cfm carb.

they are the umbrella type, I also tried putting on oring type over and under the umbrella type, made it worse. I don't think back pressure is a problem, I have hooker headers and true dual exhaust with flowmaster mufflers, and it rarely goes over 5 grand

Are they the standard rubber umbrella seals that fit over the valve stem, but do not lock on the heads?

Remember, your cam is not a 445/455 lift cam with the 1.6 rockers - it'll be a bit higher (perhaps .480) and this might be your problem. If you're not experiencing coil bind, the spring retainers might be pinching the seals. Those rubber umbrella seals are not made for high lift applications.

You will need to install the positive lock type seals, which are made out of teflon and fit snugly over the valve guide itself. I'd also still continue to run the O-rings in the retainers.