I was told by a multiple Offshore World Champ that if you cut out the flare-out at the back of a Bravo prop hub, you would pick up some MPH.
I asked him why they put it in in the first place, and was told that Merc manufactures prop to fit as broad an array as possible but that for running an offshore boat that flare had no viable purpose.
Can some of the gurus chime in or has anyone tried this and what were the results.
The flair is there to help hold the water on the blades when planing off. You can get rid of the flair ONLY if you have absolutly no slippage when planing. Hydromotive used to manufacture their props without the flair. They offered one that you could weld on if you needed it. The newer Hydromotive props all come with the flair.
Cutting some or all of the flare ring is very common. The flare ring helps in the low to mid range. It does cost speed on the top end. Typically we see about 3/4 to 1 mph speed gain on the top end with the flare reduced.
There is a down side. Some boats can be very difficult to plane off with the flare ring cut off. Since every boat is different one needs to look at what the boat is doing with the flare ring and how the boat is used. The flare ring can also affect the way the boat carries. These are all factors which have to be taken into account prior to removing or reducing the flare.
With props, 99% of the time what you gain in one area you will lose in another area. It's a compromise.
what it does is keep the exhaust from rolling back into the blades creating excessive ventalation.(air in the blades.
This is if you are running thru-prop exhaust or silent choice?
with the ring reduced you will see some top end improvments as well midrange accleration is somewhat stronger.on some boat's
boats with a very high x diminesion running a non- flaired propeller will experince ventalation or (blowout on take off usually severly. why??? is the propeller is creating thrust on take off and with the exhaust ring removed creates a vacume pulling air into the blades.
with the flair this is almost stopped.
hydromotive props are the props that have really experinced this problem in the past as far as Mercury propellers they have not had a problem with this .as the flair is not overly aggressive.or manufactured with out the exhaust flange.
Last edited by HOUSTONPROP; 01-29-2004 at 02:22 PM.
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