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Old 11 March 2011, 16:40   #11
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I think Stainless props make a difference, spent many years testing props back to back. Also Stainless props have hub kits that are designed to break if you hit something, so you dont see that many gearbox problems. I have seen loads of twisted prop shafts on ally props without hub kits! As far as getting better performance when loaded you should look at 4 blade props, they do make a difference with a loaded up boat.
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Old 12 March 2011, 06:51   #12
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I think Stainless props make a difference, spent many years testing props back to back. Also Stainless props have hub kits that are designed to break if you hit something, so you dont see that many gearbox problems. I have seen loads of twisted prop shafts on ally props without hub kits! As far as getting better performance when loaded you should look at 4 blade props, they do make a difference with a loaded up boat.
Cheers Rob

Its comming down to you for the service as soon as I get home so we can discuss then. Thanks

Mark
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Old 13 March 2011, 20:43   #13
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Originally Posted by Turbodiesel View Post
I think Stainless props make a difference, spent many years testing props back to back. Also Stainless props have hub kits that are designed to break if you hit something, so you dont see that many gearbox problems. I have seen loads of twisted prop shafts on ally props without hub kits! As far as getting better performance when loaded you should look at 4 blade props, they do make a difference with a loaded up boat.
Is there a big difference between a 3 and a 4 blade prop? I'm toting with the idea of getting a different pitch prop at the mo for some better pick up.. But I also see there's a choice of a 3 or 4 blade too! Would you lose out on top end with a 4 blade??
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Old 14 March 2011, 08:01   #14
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Is there a big difference between a 3 and a 4 blade prop? I'm toting with the idea of getting a different pitch prop at the mo for some better pick up.. But I also see there's a choice of a 3 or 4 blade too! Would you lose out on top end with a 4 blade??
Cheers
Mark
Yes you will loose on top end with a 4 blade prop, but not lots, maybe about 1-2 knts ish.
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Old 18 March 2011, 03:12   #15
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With regards to stainless steel semi cleavers, a power tech prop really did transform my cat hulled sib. But I had been getting awful probs with cavitation with the standard bunny prop which was making it pretty unusable. I was running the props shallow as my boat has a slightly dodgy transom design. If you are getting on ok with your ally prop I'd not change - it was really pricey. If it's worked fine but slight cavitation on pick up could always see if steeldevelopments can put some cup on your prop whilst they repair it? Best of luck anyways
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Old 18 March 2011, 17:00   #16
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Is there a big difference between a 3 and a 4 blade prop? I'm toting with the idea of getting a different pitch prop at the mo for some better pick up.. But I also see there's a choice of a 3 or 4 blade too! Would you lose out on top end with a 4 blade??
Cheers
Mark
If you want a prop for pick up, go for a 4 blade rather than a lower pitch 3 blade, the difference is quite surprising. Bear in mind if you do, you will need to lower the pitch by a couple of inches anyway to compensate for the extra blade.
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Old 19 March 2011, 08:50   #17
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On the same sort of set up I wouldn't bother - not enough HP to notice the differance in price ...mics 13inch pitch which covers most stuff I do . The slowness to pick up I think is due to 'only' have 50 hp trying to shift more weight ( in % terms on weight of boat probably ALOT of % more compared to a 7m RIB with an extra 3 people . ) .

I have swapped stainless for alloy on the 200hp merc and it cavitates MUCH quicker & loses about 8knts on top end speed .
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