Honing cylinders with pistons in...
 

I don't have the head off yet, but I'm expecting that my 84 XJ6 is going to have some rust in the cylinders due to the amount o water that sprayed out during the compression check.

I'm thinking it will probably be more than steel wool and naval jelly will fix. Is safe to use a drill mounted hone while the pistons are still in the cylinder, to clean up the sections that have rust?

I suppose the answer is no but you don't have much choice do you?

Maybe put a ring of grease around the top of the piston to stop anything getting down between the piston and the bore?
I'd be careful with a hone, maybe smooth emery by hand will be enough.

If its light surface rust wipe it clean, rememebr that the walls have a light oil coating on them for the pistons and rings. Rust doesnt easily start unless water left in for along time

I would not use the hone as it most likely damage the piston tops. If you have access to a ball hone it might work as there is no hard metal parts on it.

Honing with the pistons in does not sound like a good idea. You cannot get at all of the ring contact surface. What you will do is introduce bore taper which is why most cylinders get honed to begin ... to remove bore taper.

If there was rust, the damage ws aready done with your compression test with piston rings being damaged.
So why bother pulling the head if the compression test is Ok?

Just run the engine as the cilinders will now be clean anyway

I did the cylinder walls on my Triumph TR-7 by hand with 3M pads and WD-40. I had blown a head gasket and the car sat for several weeks before I could do the repair. Fired right up and ran great.
Vector

Thanks for all the input, guys! Unfortunately the head is so warped it can be resurfaced, so I'm on the hunt for a new one, and I may just go with a whole new engine . . .