ORIGINAL: SpinnerRow
I was told that the header pipes I could use are Mac's number 2591 or 2590.
I plan on picking one up this weekend. I'm going to try an APC 11x7, 12x6 and a 13x6. I probably will tune the pipe to 12x6 if, like the Evolution web site says that, the engine can turn 12,000 on the 12x6. The pipe should make that 13,000 to 13,500 or more I'd think. Stupid strong motor for a 4lb 11oz plane I plan to put it on!
Based on their hints at the timing and with prop recommendations down to 10-6, I'd be very interested to see what kind of power it puts out in the 16-17k range. 12-13k on a 12-6 is muffled generic big-block ABC .61 territory. Good power for sure! I really see potential for this engine in powering up various .40 pattern and sport speed designs, models that work well with 10" and smaller props and are designed to fit .40-.46 engines. Maybe it will be good for both.
MJD