Picking up more pieces… RC Engineering CB750 assembly continues - Examiner.com
After shedding the highly-modified RC Engineering stroker crank and rods, good replacement CB750F2 crankshaft and rods were installed in the same machined cases, which are to house the 73mm big bore top end. Getting the cases back together was pretty straightforward, but I didn’t mark the pistons properly, so when the F2 camshaft was installed, the valves hit the pistons. That required tearing the top end off again to reposition the pistons so the exhaust valve cutaways were facing towards each other on the 1-2 and 3-4 piston sets. Another wrestling match ensued to get the 73mm pistons and springy ring sets back into their respective bores. Finally I prevailed, but it seemed that the F2 cam timing was still so radical that the valves continued to hit the piston crowns, just at one spot. I had already backed off the valve springs to OEM stock, so the next thing to do was to put a stock cam back into the engine, ensuring that no more piston/valve contact would occur. Turning the engine through by hand gave the impression that everything was going as planned now, but until spark plugs are installed and the actual compression figures are noted, I may not be out of the woods yet on getting this monster motor to... Source: www.examiner.com
