Crank / conrod dilemma

[corrado]

The driveside oil seal went on my 225 Mugello after about 1,000 miles and upon stripping it down I noticed that the conrod small end had heat "Blueing" on it. It's a Tino crank with a polished conrod, 58 x 107. I've never noticed this on other conrods but I think this is the first polished conrod I've used. Is there cause for concern or is this normal? Engine was running well at the time of the strip down and if it wasn't for the fact that I had to remove the side casing to remove 3 studs to fit an ADS tour exhaust I'd never have known that the seal had gone as there was no oil inside. The small end bearing looked in good order, it was one of the bronze type. I have replaced the seal and put the crank back and was about to put the barrel and piston back on when I heard that a mate had just snapped a MEC conrod in his TS, which set the alarm bells ringing.