ORIGINAL: calvino
Most higher quality racing engines (picco......) will generally last longer than others. Funny you say the mach can make it to 10+ I have an LRP 28 and it ran for about 2 gallons with severe clutch/diff issues (slipping) in my truggy and 6 gallons later brass is showing through the sleeve but its still goin pretty strong [X(]
That's a factory defect. The chromium plating on the sleeve should never wear, only the much softer piston. If you can see brass, the plating has probably flaked off due to improper adhesion to the sleeve. SH engines aren't exactly superb quality, so it wouldn't surprise me too much.