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My heart sank when I saw that piston, but yet, plugs look great IMO. Obviously that crack is the crux of the problem, but is it just me or does it seem like there is a bit of excessive carbon build up on top of that piston?
yeah it’s a bit excessive IMO but coming from a fiesta to a RS the RS is just a dirtier engine is my guess.
 

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yeah it’s a bit excessive IMO but coming from a fiesta to a RS the RS is just a dirtier engine is my guess.
What sort of driving do you do, commuter and city/suburban driving? If so thats what I would expect the piston to look like carbon wise. I'd be interested to see any further images just for interest sake and data. Of course if its bent the rod then a cracked liner could well be the result of that as the piston cocks in the bore due to the bent rod.

Ciao
 

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What sort of driving do you do, commuter and city/suburban driving? If so thats what I would expect the piston to look like carbon wise. I'd be interested to see any further images just for interest sake and data. Of course if its bent the rod then a cracked liner could well be the result of that as the piston cocks in the bore due to the bent rod.

Ciao
i was using the car as my daily driver and weekend track toy. My commute is. 30miles one way at 85-90 every morning and about 20-25mph for the 30 mile commute home. Then the motor has also had 20hpde and 13 autoX events
 

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I know you can expect the intake valves to build carbon, but I would have thought with DI and more spirited driving that the pistons would stay cleaner. Again, that cracked piston throws all sorts of possibilities on the list. I look forward to seeing the rear down, the circumstances are a bummer, but at least get some good motor pr0n out of it ?
 

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i was using the car as my daily driver and weekend track toy. My commute is. 30miles one way at 85-90 every morning and about 20-25mph for the 30 mile commute home. Then the motor has also had 20+ race days between autoX and HPDE events.
Its the cold starting and commuting that creates the carbon issue, which isnt an issue at all really in the real world. Race engines that operate at or close to peak torque dont suffer from this because they spend their life in the region of maximum burning efficiency.In days past when we used to do a plug chop to read the fuel mixtures off the plug condition you needed to do just that, WOT and pull the clutch and kill the engine to get an accurate reading. Even a short time running the engine after the WOT would render the read useless unless the fueling was hopelessly bad. So you can imagine how commuting around and warmup cycles creates what you see.

Ciao
 
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