Hey I picked up a darton sleeved shortblock used less than 500 miles and there is some wear in the cylinders it is already at 100.5mm bore is it possible to just hone this engine as it’s already bored quite big on the cylinders and don’t want to have to buy new custom pistons


Vertical line can hang nail in

Rest of cylinders polished vertically at 12 o’clock and 6 o clock

 

If it catches your nail, some would argue that's at least 0.002" That can be removed with a hone, but the quation is after honing enough out is that outside the piston to wall spec of your pistons. You won't know till you try and what do you have to lose at this point?

 

If the scratch catches your nail, it’s likely at least 0.002 inches deep. This can be removed with a hone, which is a common practice in engine rebuilding. The critical question is whether honing will take the cylinder bore outside the piston-to-wall clearance specification. Piston-to-wall clearance ensures proper thermal expansion and lubrication. If you’re unsure, consult your engine specifications or a professional mechanic. You rightly point out that there’s little to lose at this point. If the scratch is deep, it’s better to address it now than risk engine damage later.

 

Finger nail test! Beat that dead horse.

I think of hones as a mechanism to remove minor minor minor imperfections and to put a fresh pattern on the cylinder walls where a bore to remove more-impactful damage.

A buddy had a very similar setup and he went with 101mm custom pistons from CP. Diamond will also make custom pistons for a reasonable price. Typically the .25mm material removal from the wall of the sleeve isnt a big deal but Amkkeolsa said may dictate your path to rebuilding this block.

 

what I ended up doing is selling this block and picked up a darton sleeved block at 96mm and going to bore that out to fit these 100mm pistons

 

the build I was doing is for boost and I ended up doing a 96mm stock block build as the head gasket sealing was more my concern with high boost and Dynosty/ hks doesn’t make that big of head gaskets also I believe a darton block bored that thin would oval before a stock block so I’m going to do this 3.8l later for an n/a build