Funny thing about the prop calculator...with the available info , and even making stuff up (gear ratio/existing prop sizes/hp/total weight ) ... there isn't a lot of performance difference between the various props (on the basic calculator) 20-22knt cruise @4100 , around 20-22 gph... 29-31WOT and 40-44gph ( that is a short day , with on;y 225 gal under the deck) ..... the calculator "loves" something around 17x 15(22knt cruise 31WOT)..... I'm running 20x15's have a set of 17x20's kicking around .... guess I'll have to get actual numbers on the various systems.... but short of a diesel repower I guess I have an idea of real and imagined performance
Talk about optimistic...
@4100 I would expect each engine to be nearer to 40 GPH
For My 454s 3100 RPM is about 24 kts at 28gph. I can round up to 1 GPM at about 20 kts with about 2850 if my memory is correct. All this is for calm seas. While the ride is acceptable at 20 kts in some chop the 1 GPM disappears.
My props started life as and are stamped 18X18 however the measure 17.5X17. I have small rudders among other things.
Stick with the imagined performance - it's more durable.
Regards,
S
Funny picture. I have had friends come and ask my advice about this or that 'great deal' they have found on an old boat that needs redone. I always tell them the same thing. Any time you want to fish, hire the best charter in the area, tip them handsomely, stand in the cockpit and throw crumpled up $100.00 bills in to the wake and then giggle knowing you're coming out ahead. That being said, I just like messing around with boats. Wish I had more time for them.
Funny picture. I have had friends come and ask my advice about this or that 'great deal' they have found on an old boat that needs redone. I always tell them the same thing. Any time you want to fish, hire the best charter in the area, tip them handsomely, stand in the cockpit and throw crumpled up $100.00 bills in to the wake and then giggle knowing you're coming out ahead. That being said, I just like messing around with boats. Wish I had more time for them.