Dialing in 27 Seacraft engine height, etc.

[Ed]

As most of you know, I have 27' Seacraft with new 48 inch wide body Armstrong bracket with 30 inches of setback and 14 degree transom angle. Engines are twin Honda 250s with 30 inch shafts. Boat jumps on plane and runs very flat at 51mph at 6300 rpms WOT with 15.25x17 three blade Solas props. Engines are mounted in hole number three of five. When using a straight edge coming off of hull (measured directly below motor) the cavitation plate is roughly 4 inches above hull. No trim tabs yet.

While speed is fun, rough water performance is what I care about the most - I boat in Maine and the water is always rough. When running in chop at cruise (27mph or so) at the current engine height, you can hear some prop ventilation. With the current set-up motors like to be trimmed all the way in (negative) and when I trim them out one click at higher speeds, the response is okay but not great. However, if I trim them out two or three clicks, boat will porpoise a bit.

In the interest of getting great rough water performance while maximizing fuel efficiency, I am thinking of lowering engines one hole and switching to four blade props because of their increased surface area. In doing so, I was hoping to minimize ventilation, lower planing speed and maybe give myself some more positive trim, so I can run engines perpendicular to water surface at higher speeds where fuel efficiency is greatest.

Obviously the boat is running pretty darn good and I am splitting hairs here but if you guys have any suggestions or if I am missing anything and/or may have interpreted things wrong, I am all ears.