Buju I've been inquiring on engines/specs for repower and found some notes, the new Merc 8.1L(496) is 1130 lbs, and new 6BTA (model 330B)
is 1280 lbs., no gears on both.
I've been told 440 BB, dressed with Full Cast Iron Manifolds, Exhaust Dumps, Y Fitting and Borg Warner Tranny are in the 1200-1300lb range. I'd say its on the high side...but a ballpark.
In a 1997 article in Salt Water Sportsman on a B-31 gas to diesel repower, it was reported that the 454 gas big block with gear weighed about 1200 pounds. By comparison, the Yanmar 4LH-STE 230 HP engine, with gear, weighed 950 pounds.
that is a loaded question . we must add the gear weight with it for comparison. the cummins 6bta comes with zf 220 irm gears that weight 65 lbs and the big block comes with cast iron b/w 70 or 71 series about 160 lbs so the cummins at 1150lbs plus gears around 1215lbs is just about equal to big block.after 1000 test the answer is the 31bertram fbc needs about 1400 lbs after main bulkhead to be in perfect balance ,that is water line even with chine at the stern so you need to put something either under cockpit evenly on both sides like generator,holding tank, ballast whatever.
