It be worth mentioning the on the side valves (L-heads) that a worn a valve guide can be a source of oil smoke. Most techs thinks of bad rings and install a new set to still have a smoker until they check and replace the valve guides.
I have replaced several exhaust valves guides over the last few years. At one time I could get aftermarket guides but source has dried up for me. It does require special tools ie reamers to install new guides. Most time the valve faces and seats just need cleaning up the match the new valve guide path as after guide installation they don't always seal properly until done.
Last edited by AVB; 11/04/16 04:34 PM.
