A friend of mine has a 1976 or so 42' Bruno which is NOT a cored hull. She had a 671 TI (not much hp- n90 injectors) and did about 15 knots as a light charter boat at probably 1900rpm w/ that engine. He repowered w/ a C series RECON, which I think is an honest 430 hp, maybe a wee bit more and the boat does an easy 18 knots now. I'm not sure of the rpms w/ the Cummins, but not more than 2200, I'm guessing, as he runs it conservatively. Wheel is 26 inch diameter; I don't recall the pitch, but he's got a 2 to 1 reduction and a2 inch shaft in the boat. Although those glass hulls are heavily built, they are not as beamy as today's 42' downeasters, so it doesn't take much to push them along if they don't have much weight to bear otherwise. Same boat is getting a new cabin and flybridge out of Nidacore/glass/ and West System now this winter. I have also seen 42's down here w/ 650 hp E7 Macks, QSM 11's and 600 hp Cat (C-9 I think?). The latter engines have a lot more power to spare obviously, but it depends on application and sea conditions. We are in Hatteras, NC and even 18 or 19 knots could beat the hell out of a charter party on a lot of days here, even in the summer.
