You may be over propped if the tach is accurate (if you could find a strobe light type tach, that would be a good way to check it), as I'd think you should be turning at least 4500, so a larger dia prop with less pitch might spin faster and give you a better hole shot with about the same top end. Bob used to easily cruise at 20 kts at about 9" vacuum with a Bahamas load with the 260 hp MC, which was perfect for following him in my Seafari with the 115 on it, although I had to wind it up to 4500 to stay with him. I'm sure he could have cruised at 25-28 kts if he wanted to. Might touch base with Island Trader to see how much you'd have to mod the deck and engine box to install a V-8. The Chevy V-8's are so common that you can almost buy parts at the corner drug store, so it may actually be cheaper to run a stock V-8 than trying to find an I-6 that's been out of production for years. The weight difference/balance shouldn't be much different.
Data from
Carla's website indicates that the 21 would run 40 mph with a 225 hp MC. I'm guessing that was probably a 327 cu. in. V-8.
10-11-2016, 12:12 AM
Hybrid Mode
