KA24E Rebuild: Piston rings

[mutiny]

In the process of re-ringing these pistons, and in the FSM it shows how the piston rings with their gaps should be arranged...



However I just noticed the piston has oil holes (id assume thats what they are?) on the bottom ring (the oil ring). Are the gaps of the 3 rings of the oil ring part (the oil expander, upper oil ring and lower oil ring as indicated by the above image) supposed to line up with the oil holes? Or would it really not matter or should they NOT line up with the holes?

[180fan]

don't crap a brick over that. the rings will move when the piston starts to reciprocate so yeah...

[mutiny]

Really? I thought the rings didn't spin around the piston at all, but just expand outward towards the cylinder wall. Oh well I already put all the pistons in the block I guess it should be fine eh?

BTW... what are the possible outcomes if one were to run a motor with say... a deep knick in the cylinder wall?

[180fan]

you're forgetting about when the pistons are cold. They'll expand, as they get exposed to heat, then they'll grip the cylinder walls a bit more hardcore, but they will still rotate even at the hotter temperatures, if they did not then you'd have a piston that's not freely moving and it'll dig into the cylinder walls.

How deep a "knick" are we talking about?

[mutiny]

.5 or 1mm maybe?

[180fan]

hmm you're not going to attempt to reuse the old pistons are you?

[mutiny]

I just want to know what would happen if you were to run the motor like that. Let's say new pistons, new rings, but knick in wall on block. Would you lose compression, overheat, etc etc what are the results of a damaged block like that while running?

[180fan]

running a motor with a gouge like that is the worst idea ever. which is why I asked about the pistons. You'll want to have the cylinders bored till the gouge is gone and then have the pistons sized accordingly. the rings will need to be gapped accordingly as well.

[mutiny]

You still didn't answer my question. What exactly will happen if you run the motor like that.

[LayNLow240]

where at on the cyl wall is it and what shape is the nick in? is it just like a |? if so which direction is it in? - or |?

[mutiny]

direction: horizontal like --- maybe 1/4 way down from the top

[180fan]

correction, I did answer your question. Worst idea ever. Initially you'll wear away at sections of the rings that pass by that part. over time, you'll lose compression, get oil mixed with gas, excess blow by, and other awesomeness you get with a notch in the rings.

[Black on Gold]

You still didn't answer my question. What exactly will happen if you run the motor like that.

Common sense tells you that it needs to be fixed.

[mutiny]

I think everyone is missing the point. I don't intend to run a motor in that condition, obviously it needs to be bored out and fixed. It was simply a "what if" curiosity question... I just wanted to know what happens when a motor runs with a dip in the side of the cylinder wall, as in the results and 180fan FINALLY answered the question with his last post, but never ever answered the actual question before that post, despite what he says. I never asked his opinion, whether it is a good idea or not, simply wanted to know the outcome. thanks!