6 March

Pulled piston/rods 1, 2, and 4. The rods, pins, bolts, skirts, rings, ring lands, and bearings look great – to me. Some have said the crowns show evidence of high heat but I really can’t tell.

One thing several people have said is that running 11 degrees spark timing at 220 kpa and 6000 rpm (where it failed) is retarded – literally – meaning it’s far too little spark advance. Alas – and again – Interweb searches show two very different groups, one saying that it should be around 20 degrees and the other saying it should about 10-12, right where it was. I don’t know enough to know what’s right, and it’s very frustrating not finding more of a common answer, but it matters less and less since this engine isn’t repairable and the tune for the new engine will be closely reviewed after it’s back up and running.

Currently waiting for the rest of the exhaust parts so the header build can start. The idea is to do that first so that the head (currently serving as the exhaust manifold fixture) can be delivered to the engine builder for cleaning, inspection and reuse. Quoted lead time on the engine is 10-12 weeks, so there’ll be plenty of time to rework both the exhaust and intercooler.