Prussian blue

[colin1928]

Originally Posted by J Franklin

Yes, it shows amount of contact or voids

That's what it is made for
from back in the day when Babbitt bearings were hand scrapped
I like for checking valve seat contact

[Chuck Sea/Tac]

Originally Posted by colin1928

That's what it is made for
from back in the day when Babbitt bearings were hand scrapped
I like for checking valve seat contact

So if the mainline was bored, then you should have 100% contact, and Russian blues basically a waste of time?