Piston rings

[ubxf]

I'm having a block worked on and the besides redoing the valves, the cylinders are being honed. I have a set of pistons that came from a different engine do i have to change the rings or could i use the ones that are on right now? Also same question about the springs on the valves do they have to be changed as part of that kind of work even if the old ones look ok? Many Thanks
francois

[Mo]

2 cents

I you are re-honing the cylinder walls I'd do new rings. You have it down that far. Did you look at the bearings and see how they looked? Pay particular attention to the bearings and where they go...should all be layed out cylinder 1 to 4 and their positions.

[Al Schober]

Worn rings are one of the main reasons for doing an overhaul.
It's easy to check the rings for wear - just install them into the cylinder bore and press them down towards the bottom of the bore using the top of a piston. Then measure the end clearance of the ring using feeler gauges. Clearance should be on the order of 10 mils (specs are published, I don't recall the exact tolerances). I've seen worn rings that had over 100 mils clearance - these rings were doing nothing! They were just along for the ride.

[ubxf]

Thank you guys, it looks like i have a bigger problem. A little rust spot on the side of a cylinder wall turned out to be a major problem. A scale almost the size of a dime

[Al Schober]

It looks like those cylinders have been sleeved at some time in the past - or do my eyes deceive me?

[joe_db]

If they haven't they are about to be!

[ubxf]

yes that looks like a good prediction unless i drop the whole thing. The estimates are building up so fast i'm starting to wonder if it's all worth doing it.
I'm just afraid that when it's done it might just crack. the block was mag tested and this thing pops up a few days later from a small rust spot