Boatmad.com


Reply
 
Thread Tools Display Modes
 
Old 07-08-2014, 02:14 PM   #1
Registered User
 
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
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 :/
__________________

Banana Shark Dave is offline   Reply With Quote
Old 13-08-2014, 06:10 PM   #2
Thundercat guy
 
roflhat's Avatar
 
Country: Scotland
Location: Isle of Lewis
Occupation: Skipper
Boat make: Thundercat
Engines: Yamaha 70ces

Join Date: Apr 2014
Location: Isle of Lewis
Posts: 561
Any photos of what you did? I need some rpm
__________________

roflhat is offline   Reply With Quote
Old 13-08-2014, 10:26 PM   #3
Registered User
 
Renegade's Avatar
 
Country: UK
Location: london
Occupation: Powerboat Skipper
Interests: Boats , bikes!
Boat name: Renegade
Boat make: GPV-RENEGADE
Engines: 150 HO etec
Cruising area: Thames, south coast, anywhere!

Join Date: Dec 2008
Location: london
Posts: 2,330
But what performance gains were there?
__________________
Im re branding pepper spray as Arsehole Repellant.im going to make a fortune.
Renegade is offline   Reply With Quote
Old 14-08-2014, 01:32 AM   #4
Registered User
 
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!!!
Banana Shark Dave is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Powered by vBadvanced CMPS v3.2.3

All times are GMT +1. The time now is 09:51 PM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
×