Have a 160,000 mile Altima 2.5 blowing oil. Compression is around 120 across the cylinders. Valve seals fine.I do not want to spend much on this old vehicle. Takes me less than hour to remove head and get to piston walls and not taking pistons out through the pan. Will just honing cylinder walls as deep as I can get the piston on the down stroke and no ring replacement give an improvement in compression and reduce oil burning? I would think for sure it would but need second opinions. I think it would definitely help the old rings re-seat some.
What you're suggesting will not improve your compression and will cause other issues. You'll be causing yourself more issues than what you have currently.
When an engines are put together with new piston rings, the cylinder walls are honed to allow the rings to seat against the walls, which means they are sealed. By re-honing only a portion of the cylinder with the piston still in the bore, you'll create a step at the lowest point the hone can reach, which will cause the seating action of the ring to be disrupted.
Secondly, when you hone a cylinder, it's done with abrasives. These abrasives from the hone get left everywhere. The only way to clean these out is through disassembly. If you don't clean out the abrasives, they will continue to wear the internals of the engine and just exacerbate your situation.
You will NOT gain anything by going the approach you're talking about. In fact, you'll only make matters worse. You could possibly completely dismantle the engine and re-ring the cylinders. You'd only put a light hone on the cylinders, just enough to break the glaze. Then put it back together and hope for the best. This might work, but it really depends on the wear of the cylinders. Your next cheapest option would be to buy a JDM engine with light miles on it and install it. I bought one for my Honda which only cost me a little over $500 here in the States.
The other thing to think about here is ... why is a Nissan engine having issues at 160k miles? Most of the time, this comes down to poor maintenance. Japanese engines (pretty much across the board) are very reliable engines if you keep up with the maintenance. They will fail you if you're not doing proper oil changes or beating on it. So maybe the mod which needs to happen here is called the driver mod, or whatever you do with this engine or future engines will end up just the same as this one. Just a suggestion.