Replacing piston rings

[Sam's GSX]

Ok, so I have the engine split, block still in the car, I'm shimming my valve springs at the moment.
But, while I have the engine apart I'd like to pull the oil pan and replace the piston rings on 1 or 3 of the pistons, and I have two questions.
1: my compression test after about a week off driving the engine was
1. 165
2. 161
3. 130
4. 184

So, do you think I should redo the rings on 1, 2 and 3? Or just 3?
Money is tight. But I'd rather do it if it will be better.

And question 2: when I have new rings in, and oil rings at least still on one, is the breakin process the same as if they were all new? Like get into boost and decel to seat the rings?

Any help is appreciated, thank you

 

[Sam's GSX]

Ok, so I have the engine split, block still in the car, I'm shimming my valve springs at the moment.
But, while I have the engine apart I'd like to pull the oil pan and replace the piston rings on 1 or 3 of the pistons, and I have two questions.
1: my compression test after about a week off driving the engine was
1. 165
2. 161
3. 130
4. 184

So, do you think I should redo the rings on 1, 2 and 3? Or just 3?
Money is tight. But I'd rather do it if it will be better.

And question 2: when I have new rings in, and oil rings at least still on one, is the breakin process the same as if they were all new? Like get into boost and decel to seat the rings?

Any help is appreciated, thank you

*and old rings still on at least one

 

[motomattx]

Friction seats the piston rings, you dont have to do any coasting etc with it, just run it in easy and you should be set as long as the cylinder has cross hatch in it that is in good enough shape, if you are buying a complete set of rings replace them all, by the time you try to find three sets of rings it will be just as much to buy all four in a box, there are packaging costs to separate ring sets you see, dont try to re-use any of the rings, not the top rings, not the oil rings, none of them.

 

[Sam's GSX]

Ok I'll look for a set of 4, and yeah I wouldn't reuse any, thank you man

 

[dustyboner]

As soon as the engine starts, immediately bring it up to an above-idle speed. According to JE’s Senior Technical Account Manager Alan Stevenson, “You don’t want to break-in an engine at idle. You want to keep the rpm above 1,500 and vary the speed continuously for about the first 20 minutes.” After bringing the engine up to normalized coolant and oil temperature, put the engine under load. The cylinder pressure from 50 to 75 percent and eventually to 100 percent load will place additional pressure on the back side of the rings which will quickly establish the proper wear pattern for seating. With today’s rings, especially moly-faced versions, this can be achieved in a very short period of time and certainly within 20 to 30 miles of street driving.

you can read the full article HERE