Why Not Run Bravo as Surface Drive?
03-18-2012, 02:03 PM
#11
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I just got an email from a guy who is running his Imco SC (XR equivalent) with the prop shaft 2" below the hull line on his 21' Daytona, using a Bravo 1 prop. He has a friend who is 1/2" below hull line, with the same prop. Both report no problems so far. I keep wondering how they are getting away with this. One is running 670 hp at over 119, and the other almost 800 at over 130. They do run in calm water, and, of course, the boats are light, comparatively speaking to your typical offshore V-hull.
Michael
Michael
03-18-2012, 04:21 PM
#13
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Keep spare parts on hand, 800hp tears XRs apart like nobodys business. The gears in the Max Works, IMCO SC, Teague drive ect. are still just stock XR gears, nothing more.
03-19-2012, 01:54 AM
#14
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The props always crack and then tear from the trailing edge of the blade, midway down. I have had one crack, one with a blade completely gone, and one with a blade hanging off. no damage to the drive other than a small knick where the blade hit the cavitation plate.
03-20-2012, 11:33 PM
#15
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I have a short X, right about 3" below the pad. I always run labbed props, i know they are ticking time bombs, but they just run so much better. I have a 725-750hp 598ci N/A. I do get alot of air time, but am always careful on reentry.
The props always crack and then tear from the trailing edge of the blade, midway down. I have had one crack, one with a blade completely gone, and one with a blade hanging off. no damage to the drive other than a small knick where the blade hit the cavitation plate.
The props always crack and then tear from the trailing edge of the blade, midway down. I have had one crack, one with a blade completely gone, and one with a blade hanging off. no damage to the drive other than a small knick where the blade hit the cavitation plate.
Now you guys are going to be jealous. I just got an email from a friend with a 21' Daytona with 682 hp. He said he's had no drive failures (Imco SC), and no prop failures even though the prop shaft is only 2" below the hull. His buddy with 800 hp, and prop shaft only 1/2" below the hull has been running the same prop for 9 years! They also do full throttle hole shots.
As an engineer, I have been trying to figure out what the magic formula is. The only thing I could come up with is 1) light boat so not heavily loaded most of the time, and 2) prop rarely leaves the water (they only do lake and delta boating).
If anyone else has some theories, I'd love to hear them.
Michael
03-21-2012, 01:50 AM
#16
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The magic formula is the amount of/lack of weight its pushing and the smooth water.
I think my freind who owned a 42 Fountain poker run with a very high x dim and stock 525efi's threw blades off 2 or 3 props in less than 50 hrs.
I think my freind who owned a 42 Fountain poker run with a very high x dim and stock 525efi's threw blades off 2 or 3 props in less than 50 hrs.
03-21-2012, 02:39 AM
#17
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Thry also have been seen behind a few Cig 20's with standoff boxes and they seem to run real well in those, whats the Hull your rigging with the BH drive?
