Buddy,
I worked on several R & D programs for commercial products. Guidelines for use of funds were 1/3 for direct costs (labor and materials), 1/3 for indirect costs (general and administrative), and 1/3 for profit and taxes. In the first couple years, Cyclone met the guideline ratios of R & D to G & A (see Use of Funds above), but with no provision for profit and taxes. That is where the percentages went off the rails until the G & A funds were double the R & D over the life of the program, with no mention of profit or taxes.
Benjamin Franklin said, “One of the greatest tragedies in life is the murder of a beautiful theory by a gang of brutal facts”. In the engine world, the gang of brutal facts is extended third-party dynamometer testing under controlled conditions with published data. There will be no 1500 HP Cyclone engine, although it is a beautiful theory.