What is gained or lost by shortening the barrel on a thru hub prop ?
What is gained or lost by shortening the barrel on a thru hub prop ?
If it is a flared barrel, increased bow lift, less stern lift. Straight barrel, not much anywhere.
that confirms what I was thinking.
I thought the flare lift the stern and the whole boat .
Stern yes, but on many boats it will drive the bow down. I started cutting the flares a dozen years ago just for this reason. It drives the bow on a Stroker down. Other boats work better with the full flare.
Have seen it push the bow down on an Allison before. I believe that's one reason when most full barrel props are worked for hi-po boats they trim on the barrel.Originally Posted by John Jackson
Exact opposite of this...flared barrel for more stern lift and less bow lift. Straight barrel for less stern lift so the bow can rise. I run a flared bell to purposely keep the bow down and lighten up the stern to run flatter. Strokers and Allisons like the smooth barrels to get the bow up...Bullets like to run flatter with a flared barrel.
96 Bullet 20cc, Yamaha OX 250+, 10" jack, labbed 30" Bravo LH w/1.25" exhaust pipes, counter rotating Bob's lower, it goes faster when you spin it the other way...
So if I have a nose heavy boat (champion weighted down) could it benefit more from the Bravo LT vs the Bravo XS?
I doubt that you'll notice much of a difference between the two props on your boat.
These guys are right about it not mattering too much on a heavy hull. Gonna need to cup it for sure to get the bow up cuz Bravos don't have much cup from from the factory. Probably gonna do better with a short barrel (no flare)...but flare can be adjusted in the direction of fully flared to no flare by trimming off a little at a time til it's right. Just can't add flare to a non-flared barrel. Best prop I ever ran on a heavier Champion was a "High Five"...older 5 blade Merc prop.
96 Bullet 20cc, Yamaha OX 250+, 10" jack, labbed 30" Bravo LH w/1.25" exhaust pipes, counter rotating Bob's lower, it goes faster when you spin it the other way...
Best as in speed or handling? I figured a 5 blade would be awful for speed.
You guys know anything about the rev4 props?
Really shines on holeshot, acceleration, carrying the bow, handling and turns like a Ferrari...all at the expense of 2-4 mph (depending on rig and set-up) on the big end. Has thicker blades and an extra blade that increases drag and trims the mph slightly. I still have my high five from my Champion days...it's a 25 pitch with a very slight flare on the end and some cup in it too...in pristine condition too. I would let you run it no problem if you came to me...
Last edited by Bullet 20cc; 10-22-2017 at 07:28 PM.
96 Bullet 20cc, Yamaha OX 250+, 10" jack, labbed 30" Bravo LH w/1.25" exhaust pipes, counter rotating Bob's lower, it goes faster when you spin it the other way...
I've run a 27 Bravo XS old style with 1 inch holes on a champion 202. It runs good. Not as fast as a tempest plus though
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