Marcus,
Tom is right. Oil flows from the lifter gallery onto the timing chain,
it's a drain-back hole plus a source of lubrication for the timing
chain. The roughness is most likely casing flash. Most engine
rebuilders remove this as it can sometimes break off and cause other
problems but if it's been there this long it'll probably stay where it
is.
Steve Ferguson
'76 EII
San Diego
Tom is right. Oil flows from the lifter gallery onto the timing chain,
it's a drain-back hole plus a source of lubrication for the timing
chain. The roughness is most likely casing flash. Most engine
rebuilders remove this as it can sometimes break off and cause other
problems but if it's been there this long it'll probably stay where it
is.
Steve Ferguson
'76 EII
San Diego
