I've just pulled down my A14 to check it out and with the pistons at TDC there's about 1mm play in the pistons and a bit of a lip. So as the topic, how much is too much play? Will I be able to get away with a hone and a standard set of rings? ..or is there too much wear?

On the plus side all the journals/bearings are like new Gotta love how bulletproof these things are


Cheers,
Sam

Obviously it was still running but you'll be changing the oil heaps more in that condition and as a rule people have told me there's not much point in going oversize rings to fix that problem.

We run race motors with that much clearance.Unless your thinking BIG k's i'd hone it but i'd also fit standard chrome rings as opposed to the crap black ones and give them a good run in.
Enjoy & Cheers

Are you sure that there is really 1mm play in the piston? That's like 40 thou - which is the second oversize (if it's really that much).

Generally speaking go by the lip size. If you can take a pic and upload it, it's probably easy enoughto answer going by the picture.

One thing - though some people will not realise this one - do NOT use a ridge-remover to take out the lip entirely. Although it seems like they will, new rings on the old pistons will NOT cause the top of the ring to hit the ridge and damage it, If you are REALLY worried about it, just cut 1mm off the bottom of the lip with a scraper (believe it or not you can do this with cast iron, or use a small file).

But leave the rest of the lip at the top. The reason is simple. With more bore wear like a situation like this, the new rings (top ring mainly) sit out further from the pistons, so they get exposed to a hell of a lot more heat and flame front, esp close to TDC. If you leave the lip in there it actually helps protect that top ring and the 'budget' rebuild will last a lot longer.

That's one of the sneaky things that can shorten the life of a rebuild that doesn't go to the next oversize and use new pistons. (the other one is not washing the bore out after you hone it - solvent isn't enough, hot soapy water and stiff nylon scrubbing brushes or the debris from honing is trapped in the bore cross hatch pattern and takes a massive toll on new rings)

Don't use oversize rings unless you run oversize pistons, they are made to suit teh piston, and even if you had 2-3 times the ring end gap, in practice the leakdown from that is so minimal it's of no concern whatsoever. In that case run std rings but get 'file fit' rings, which are made for a std bore, but longer circumference with stuff all end gap, and you carefully file them to get the end gap right.

Also check that the ring clearance (top to bottom) inside the ring grooves in the pistons are ok, sometimes on high mile engine, the ring lands which support them get 'bruised' and open up the clearance too much to hold the ring 'true' against the bore.