Akro,
Johns article comments expressly refer to a TNIO550 or 520 with TN being the operative. The MP is 30" (+/- a bit) and not the same as your 38" so as Walter has commented, the fuel flow and BSFC is going to be much higher, and he means much higher. To have a lower compression means higher EGT, but with the much higher MP and a need to maintain a detonation margin this means a much higher fuel flow per HP, or a higher BSFC at takeoff powers.
Still in Perth, and not able to dedicate hard numbers but the fuel flow will be rather high at takeoff. I see your conundrum.
Perhaps JD or Walter will get an answer sooner but I need some sleep right now.....will study the manuals you sent me and see what we can come up with.
