treywil Posted June 16, 2016 Author Posted June 16, 2016 The boat finally saw water this evening! Testing some props and she's a great running boat so far. Have to try 1 or 2 more props and once the leaning post gets built it will be ready to roll. I will say it likes a 4 blade prop better than a 3 blade. She hops right out of the hole and turns on a dime at speed. Very well designed boat Graham and Alan! Will post final performance numbers soon when it's dialed in but right now I'm seeing 2.2 gph at 22knots, nothing short of amazing in my book! Quote
Alan Stewart Posted June 16, 2016 Posted June 16, 2016 She looks great. Thanks but I can't take any of that credit, Marissa is all Grahams hard work and experience. I'd be happy to draw a boat half as good as that. 1 Quote
treywil Posted June 16, 2016 Author Posted June 16, 2016 I wasn't sure and didn't want to leave anyone out! Can't wait to see how it handles some currituck sound chop. Quote
treywil Posted June 30, 2016 Author Posted June 30, 2016 I've experimented with motor height, props, and various loads and settled on a 13 1/4 x 15 cupped 4 blade prop. I'm mostly after low end torque and fuel economy and this prop works very well. It's slightly under propped with just myself but the hole shot and economy at cruise is exceptional. I'm seeing 1.8gph at 20mph with a top speed of 32mph. With a 3 blade I was able to see 35mph but cruise economy and low end power weren't as good. My boat and motor combo also benefited from the stern lift of the 4 blade prop. There was a slight tendency to porpoise sometimes with a 3 blade but I did not do very much testing with the 3 blades. The boat handles light chop and boat wakes very well even given the light displacement. The bow section just splits the water as intended by graham. I guess this is a wrap until I get the money to start the next one, maybe the ocracoke 20 or 25. A 22 or 23 would be just about perfect though. Thanks again to Graham for designing a great small boat! Hope this info can help future Marissa builders! 1 Quote
treywil Posted June 30, 2016 Author Posted June 30, 2016 And another note regarding the prop, mathematically the prop can not even go the speed I'm getting at wot but I've checked and re checked rpm and speed and it most certainly does. I can't figure that out but it's an older stainless turbo. Maybe they were conservative with pitch measurement? Quote
smccormick Posted July 1, 2016 Posted July 1, 2016 I'm no expert on prop performance or Etecs, but your economy numbers seem a bit off. I'm just guessing here, but that boat should be north of 3 mpg. You may be leaving some performance on the table with your selected prop. Here's a comparable performance bulletin for your review. Obvously not the same boat but certainly not any easier push. http://www.evinrudeuae.com/Content/Pdf/neutral/performanceReports/PE771.pdf Not trying to be argumentative, maybe I've been reading THT too much. Oh, and nice job on the new ride. Love the color. Quote
treywil Posted July 1, 2016 Author Posted July 1, 2016 Not sure how it could get any better. 1.8 gallons per hour at 20 miles per hour works out to 11.1 miles per gallon at that speed. If I am missing something I'm all ears, I won't turn down more effeciency! Quote
smccormick Posted July 2, 2016 Posted July 2, 2016 BEEP, BEEP,BEEP; that's the sound of me backing up. Sorry I read 1.8 mpg. Nothing to see here moving along. Sorry. Quote
PAR Posted July 2, 2016 Posted July 2, 2016 There's an awful lot of greens, that's a "split pea" green to me. 1 Quote
treywil Posted July 3, 2016 Author Posted July 3, 2016 No worries, I do the same thing sometimes! Your 25 is coming along nicely btw! Quote
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