4 Mar

It’s interesting the widely (wildly?) differing opinions from people who really know this stuff, the latest being comments that the plugs look good, with no sign of detonation. That was yesterday. Today the injectors and test results came back – note that I didn’t tell them what had happened or which one was suspect. Looking at the results sheet, well son of a… (by chance, #2 on the sheet happens to be cylinder #2). I’m very surprised, given that a 10 micron filter is immediately upstream, though I don’t know how large a particle the injector can pass without clogging, what if it’s only, oh, 8 microns – I’ll have to ask them. Additionally, I’m surprised they only flow 1400 cc wide open because they’re advertised as “1650 cc” injectors at the same pressure. Not sure what to do with them – sell them and get… what in their place? How would different injectors prevent this from happening again?

The experts have settled into two groups. One says the failure was “absolutely due to detonation, with signs of high heat.” The other says “no signs of detonation, the rod big end or a rod bolt failed due to a manufacturing flaw.” The picture of the piston bottom shows virtually no heat, unlike what the pro-heat camp suggests would be present as a dark or black area (the gray area is where the destroyed rod hit the piston). Then there’s being told that running 11 degrees timing is nuts, that it should be more like 20 degrees or so. Mind you, I didn’t pick the timing values, the tuner did, though I’m still ultimately responsible for keeping an eye on things.

At this point, examination of the evidence is pretty much done and I’m left with the dubious knowledge that about all I know for sure is that one injector had a very poor pattern. Time to move on with the new build, intercooler, and exhaust setup.

I just realized something – that my fuel filter and regulator may not be ethanol-compliant. Now wouldn’t that be an expensive lesson if that’s at the root of this?