I was doing a leakdown test on a h23 that had been sitting for about 2 years, it was leaking almost 50% from the rings on #2-3-4 cylinders. I decided to tear it down and check whats up, i noticed this;



Very similar pattern, those scratches are easely felt, and are all on the intake side. Exhaust side looks mint on all cylinders.

Anyone has a clue of what could have happened?

 

piston slap. less clearance and pistons in the cylinders microscopicly wobble up and down as the crank rotates..(piston rings were bad/not set right)

 

isnt piston slap caused by excessive ptw clearance and normally has the skirt hit the sleeve not the top of the pistons?

would this situation be too tight ptw or too hot and the piston top expanded and caught the cyl wall?

what do/did the pistons look like on the intake side

 

Well i got my answer today; ringlands on these exact spots were all cracked to the point we could take the chunk out by hand. I dont know what the hell this engine has been trough, but it did take a serious beating...

 

Judging by all of the rust build up in the water jackets, probably has lived a hard life.

 

Just for the sake of future viewers, the type of wear is a thrust wear. This type of wear is generally seen on engines with a poor piston to bore clearance, but in this case, broken ring lands.

This is normally seen on turbocharged or supercharged applications beyond what the piston can handle, resulting in a broken ring land. Detonation is also suspect.

 

by poor is it usually too tight or too loose piston to wall? trying to learn for my next build and for others who may search in the future

 

A good tight clearance is key to long engine life in a Honda ,.001".

The lines that run across the bores on the bottom (white horizontal) are from the skirt of the piston hitting it, indicating a loose fit in the bore, or engine wear taking its toll, or both.

Was that engine equipped with nitro, turbo or supercharger? Haven't seen to many N/A Honda's break ring lands.