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Old 07-08-2014, 02:14 PM   #1
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Country: UK
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Boat name: Shamu
Boat make: Banana Shark 770
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Prop work

I have machined the inside of the hub on my bravo 1 prop and blended the join at both ends. Rounded off the metal where the bushing joins the hub and a few little other things and given it a good polish on the outside of the blades and the inside of the hub.

To my amazement I have gained nearly 250 revs, feeling really pleased with myself, but a little surprised at such a gain. Suddenly it all came clear why when the engine stopped.

Some barstards nicked all my fuel again :/
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Old 13-08-2014, 06:10 PM   #2
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Any photos of what you did? I need some rpm
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Old 13-08-2014, 10:26 PM   #3
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But what performance gains were there?
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Old 14-08-2014, 01:32 AM   #4
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Country: UK
Location: Gosport
Occupation: Own a small building firm.
Interests: Boats, kids and looking after the Wife HaHa
Boat name: Shamu
Boat make: Banana Shark 770
Engines: Mercury XS300
Cruising area: Solent

Join Date: Aug 2013
Location: Gosport
Posts: 368
Thundercat Guy

I'm on FB mate and loads of pics on there. I'm friends with all the Thundercat racers, I use to race.

Paul/Renegade

Other than the Flywheel and exhaust which both make a huge difference that you can both feel and hear. The engine now revs like a motorbike thanks to the lightened flywheel.

No other single thing on its own has made a noticeable difference, ( bit like running 99 octane fuel over 95, or leaning out the 2 stroke oil or adding octane booster) however I have found that the 10 or so small improvements I've done when all added together have made a difference. Nothing drastic, but if your racing it's the difference between winning and losing.

All my props were over pitched, loosing weight (mainly from the hubs) seems to equal 1 degree of pitch and the various other engine and exhaust work is improving power and gaining me revs. So instead of having to buy new props, I have made use of the old ones and gained some speed and acceleration.

I have just finished lightening a Ron a Hill eagle 3 prop, I've managed to trim off a touch over 20grams and blended the square edges on this over the hub exhaust prop. It's not going to make a drastic difference, however I have extensive records for this prop on the current setup. So any gains/loses will be easily found!!!
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