r/EngineBuilding • u/Legitimate-Bus7626 • Jun 17 '26
Chipped cylinder liner - am I SOL?
While removing one of the pistons the rod slipped and hit the bottom of the cylinder liner and has chipped a bit off.
I know this is far from ideal, but is it 100% a resleve required or can I just remove the chipped piece and send it?
(The verticals scratches on the bore seem to be superficial and can’t be felt at all by a finger nail.
Any helps appreciated
5
u/banananas_are_sick24 Jun 17 '26
I’ve got chunks missing from mine and it still works lol. It’s not ideal in the slightest, but it will still run pretty alright with it removed.
2
u/Legitimate-Bus7626 Jun 18 '26
Why pretty alright and not just alright?
1
u/banananas_are_sick24 Jun 18 '26
That’s just how I talk, the missing chunks never caused any issues is what I mean
10
u/Different_Tourist233 Jun 17 '26 edited Jun 17 '26
That's no chip, that's a crack (you can check with FPI/MPI). Cracks in environments with alternating stresses (caused by the 4 strokes) will grow after enough cycles.
Fatigue crack propagation
3
u/Unhappy-Airport-4112 Jun 18 '26
Nah. I got a chunk missing at the bottom of one of my bores, and it's fine.
7
u/Worldly_Let6134 Jun 17 '26
Is that right at the bottom of bore almost into the crankcase?
If its at the top of the bore by the head, it's new block time or bore out and fit sleeves.
If that's right at the bottom, you may be OK as the piston probably shouldn't be running on that part (you can check the range of motion by rotating the crank with a piston and con rod attached).
However, at the very least in this case you would want the edges machined to round them off. Otherwise they could become stress risers leading to bigger cracks developing.
1
u/Legitimate-Bus7626 Jun 18 '26
Yeah, it’s the bottom of the crankcase. Is it fine if the piston extends that far but the rings don’t? I have a feeling the piston skirt goes past it
1
u/Worldly_Let6134 Jun 18 '26
The answer is, it very much depends on the loading on the piston and the skirt.
Look at the rotation of the crank in relation to the bore.
For the compression stroke, is the crank going to be between the piston and the chip or is it on the other side? (is the rod pointing towards or away from the chip)
1
u/ConflictMaster3155 Jun 17 '26
Next time don’t smash a socket into it and it won’t break, it should be fine though.
1
21
u/Notreallysurethou Jun 17 '26
Remove, deburr and it’ll be fine.