Whose fault?

[seg400exr]

After less than a tank of gas I decided to take my engine apart because it was running like crap and to my dismay the piston is toast. It is all scratched in the cylinder and pices of aluminum are on the cylinder walls. There are also wear makes on the sides where the studs are. I took the piston to my Honda dealer and the mechanic said the bore was to small. Then I when to the place that matched the piston with the cylinder and he said it was my fault because I didn't space the oil ring gaps properly. I am just wondering if it was my fault or the guy I had do the cylinder.

[duke416ex]

Did you space the oil ring like the instructions said?

[wilkin250r]

If there is ANY possibility that it might be your fault, the shop that did the boring is obviously going to deny responsibility, because they don't want to pay for it to be fixed.

That being said, a proffesional mechanic should be able to easily tell the difference between a ring-gap issue and a siezure caused by a bore too tight.

im gonna say its the genious who bored the cylinder.. that would really have nothing to do with your oil ring gap not being correct.. if the bore is too small the bore is too small..

Id take it back to them and demand them to replace what was screwed up by there half ***'d machine work.. but thats just me..

Jesse

[seg400exr]

I did put the rings on wrong. I was just wondering if that would cause it to destroy the engine that fast. I will definitely never put the rings on wrong again. I was also wondering how much bigger the bore should be then the piston.

[wilkin250r]

There are a few different aspects to consider. Air-cooled vs liquid cooled, the piston material (cast or forged aluminum, silicon content).

Generally, the piston will come with instructions on recommended bore size. .001" clearance is dang tight, but they exist ( I have one). 0.002, .0025, and .003 are probably most common. There are a few that are even larger, but mostly application-specific (like a nitrous motor).