Cylinder wall

RAYMOND259

Member
Nov 14, 2006
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I got my block back from the local machine shop each cylinder wall have a line in it I ask them about it they say it normal because of the bored gauge tool.I can feel it with my finger nail just little bit.it run top to the bored and to the bottom
 
are you asking if that is normal??
i have never had a block bored, but i've seen blocks that have been and i dont remember any lines, but if the shop said its normal then it will probaly be ok.

is it a well-known shop in you area or are they new?
 
When I bore an engine it is to cut metal out of the walls. When I hone (for moly-faced rings) I will make the wall almost smooth as glass. (400grit finishing stone) There should be no 'groove' in the walls or you will have excessive blow-by, reduction in compression, worn out rings (faster than normal) Not good.
 
A freshly bored & honed cylinder should not have a "line" that you can catch your nail on from top to bottom.

Finishedbore.jpg
 
Those are called witness marks. They are from the dial bore guage. The bore guage is spring loaded on the centralizer points. So they lightly touch the walls and leave witness marks due to the spring tension. They do not hurt anything. Most shops will hone out the bore to the final size and keep guaging the bore untill the final size is achieved. Once it is achieved then they will give the bore a couple of brush strokes to get rid of the witness marks. Some shops do this and some don't. If you can feel them with your fingernail, take it back and have them brush up the bore a bit.