Mercruiser Bravo drives, duo prop' selection

P

PCUK

Well-Known Member
Joined
29 Jun 2005
Messages
8,588
Location
Westleigh, Nr Tiverton, Devon.
Visit site
How is a Bravo 3 duo-prop' set selected when the engine isn't a Mercruiser? Is there a set of tables somewhere or an app' as per standard prop' selection calculators?
Also, how are Volvo Duo-prop sets selected?
Thanks. PC
 
Good question and one I have been trying to get a handle on for quite some time without real success. I know Volvo if you ask them will send you out a questionnaire on the dimensions of your boat in quite high detail plus engines and gear ratio's. If you send that in they have a program that will number crunch it, but other than that I believe the OEM boat manufacturers work with the engine manufacturers and after testing come out with a standard spec. Mine apparently is B5 but the manufacturer also believes my boat is 6.5 tons dry and it's actually 8 tons full fuel empty water and B5's are loading the engine. C4's which feel slightly finer are about right when the boat is moderately loaded but C3 is wildly under propped. I stand to be corrected but I think there is roughly 400 rpm difference between a C3 and a C4 and what I'd really like is a C3 and 3/4. I'm not sure where to go from there, A series, J series or what. It's expensive to suck and see.
 
There was a site in America called Prop Gods. They have a similar program and may be able to help. they are a rash on the American forums but stopped doing the forum side and now just have a shop. Get in contact they may still be able to advise. Or Google. they were on all the large forums

archives : Prop Gods
 
You must log in or register to reply here.

Share this page

Top