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Old 08-18-2009, 09:51 AM
1bayouboy 1bayouboy is offline
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Join Date: Jul 2006
Location: Mount Pleasant, SC
Posts: 592
Default Re: Volvo I/O question

On the single versus duoprop question.....I repowered a heavy 24 WAC with the 5.7 FWC Merc and a Bravo 1. I definitely had the Bravo one over geared at 1.5:1 and was using a 15 pitch Rev 4....WOT about 41MPH at the WOT RPM of 5150 with a cruise of around 27mph getting 2.6-2.7mpg. I picked a Bravo 3 with 2.2:1 gearing and using a 22 pitch prop set I could hit 44mph at 4900RPM, cruise at 30mph and get 2.9mpg. Added benefit was better idle speed tracking (less bow steer) and a bit better planing speed (although I had a permatrim on the Bravo I and with the stern lifting Rev 4 it did pretty well at low speed planing). The difference in a "package" cost for getting a Bravo 3 vs a Bravo 1 was something like $40. Can only wish I'd gotten the Bravo 3 originally. The cost of props steered me away, but you can find prop on ebay much cheaper than new.

Bottom line, the duo prop should out perform the single in every category....mine certainly did with the merc.
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