C3 1970 454 Big Block 300 mile range one quart of oil consumption!
I have had this 1970 Big Block fully restored And running since 1997. Second and Top Flight judged in 2008 and 2011. Engine was rebuilt by Custom Speed Enterprises to stock, just had to get it running and finish putting back together. Since day one and 10,000 miles later it has always used a quart of oil every 300 mile which I think is very excessive. The spark plugs are always black and oil wet. Why? What's going on here? Using Shell Rotella 15W40. Have tried many different sparks plugs, my best ones are Champion. Can't run new AC DELCO plugs, they always fail. I have saved the last two sets of plugs to examine. Can post pics. I know when the engine starts not all cylinders are firing until oil clears out. Very short blue puff of smoke at cold start, otherwise exhaust is clear. Runs great. I've heard this is a very common problem. Valve stem guides/seals? Intake manifold leaking oil into pushrods valley. 4Speed Convertable. Why can't this be fixed?