Trying to get rid of porpoising
#1
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Trying to get rid of porpoising
I have a 28 Pantera with 425hp 454's and number III drives. Right now it has 4 blade 28 pitch props on it. It will only turn those to around 4200 rpm's and it porpoises bad. I was wondering if going to a set of 3 blade 27 pitch props would help it out? I have only used the boat for one weekend so far and the water was smooth so I don't know how bad the porpois is in rougher water.
#4
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I think the 23-24 P will be close. If you can't find a set to test with, BBlades has a nice loan/swap program.
Last edited by BenPerfected; 05-16-2011 at 01:22 PM.
#5
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K planes need to be about 3 to stop it and it does not run free at all, you can feel the bow being held down. Which props are better for porpoising 3 or 4 blade? The boat used to have 600 plus hp and ran in the 80's with these drives and props. The guy I bought it from put these 425 hp motors in it. Will weight in the bow help, you think?
#7
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My 33 fountain had III's on it and I had the same problem. I went up in diameter and down in pitch. I had 26x16.5 and I picked up 8 mph. Felt like a different boat. I also tried some 29 x 17 three blades and they ran the same top end but lost some on the cruise.
#9
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So more diameter would increase transom lift, correct? Is that what I need to stop the porpoising, transom lift? Do I need to get 16 or bigger, or would a 15 3/4 3 blade be better than what I have?