So just finished freeing up and removing all my 70 4.2 L pistons . The rust appears surface only but I think I need to do some honing to confirm the condition . Recommendations welcome.

 

Mic the cylinder walls after honing them and if there is a lip at the top borrow a ridge reamer so you won't damage the new rings is my two cents worth!

 

Worth a buck at least !! Thanks

 

When I rebuilt my 4.2 litre around an uncracked block, (another story !), in the early 90s I bought a drill-operated hone specially made for the 4.2 litre engine. It looked like a wire brush with blobs of material on the ends. It cleaned up the bores nicely and the engine ran beautifully afterwards.

 

I thought about using one of those but I heard on a YouTube from an experienced performance builder he does not recommend those hones unless your sure the cylinders are not tapered as they will only follow the existing cylinder contours which could already be out of whack. If your using a drill mounted hone he recommends the three legged type that have long stones on each leg as they are more likely to keep, or even improve the straightness of the walls.

 

We used those "wire brushes with blobs" for years for honing aircraft cylinders.
Worked a treat. No problems