Cylinder #3

Cylinder #4

 

Awesome pics and really confirms what I've always maintained, i.e. if you don't have a spray wash over the valves you're going to have carbon buildup no matter what they say about using Tier 1 gas, synthetic oil, etc. You might be able to reduce it slightly by having less burn-off from dino oil and unburned impurities from cheapo gas, but there's no real substitution for having the fuel spray above the valve instead of directly inside the chamber. That's why everyone with GDI is switching to a hybrid model, where you get the fuel economy of direct injection but the cleaning power of manifold injection. Overall though your combustion chambers look pretty good, you really don't have much carbon buildup on your pistons and looks like really clean piston chamber walls. You can still see a real nice cross-hatch pattern.

 

What are the reddish drops? Looks pretty average for aGDI engine that hasn't had any valve clean/carbon clean treatments like BG or CRC.

 

I don't know...rust stains???

In the one picture it looks like a drop or small blob off some rust colored liquid but I think that is an optical illusion. I believe all the cylinder faces were dry.

 

Too cool. I need to go get walnut blasted...