The bore may include {HEAD ~ a first radial inner surface} at the first lobe portion and {TAIL ~ a second radial inner surface} at the second lobe portion 
The bore may include { HEAD ~ a first radial inner surface } at the first lobe portion and { TAIL ~ a second radial inner surface } at the second lobe portion
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH