help bravo 3
#1
Gold Member
Gold Member
Thread Starter
help bravo 3
help. fitted 2 high reving Mercedes diesel engines to my boat am on bravo 3 outdrive with 1.5-1 gears 22p props it will only get to 1200 rpm 10 mph
max should be 5500 rpm.?? i can exchange gears to 2.0-1 will this do the trick?? the turbos on the engines spool up around 2800 3000 rpm with a bang.
tested on a rough engine dyno to 250 bhp 5500 rpm. if i go 2.0-1 and stay on 22p props will this do the trick ????? thanks ricky . boat is a 28 ft speedboat fast plaining only 6000 lbs all in.
max should be 5500 rpm.?? i can exchange gears to 2.0-1 will this do the trick?? the turbos on the engines spool up around 2800 3000 rpm with a bang.
tested on a rough engine dyno to 250 bhp 5500 rpm. if i go 2.0-1 and stay on 22p props will this do the trick ????? thanks ricky . boat is a 28 ft speedboat fast plaining only 6000 lbs all in.
#2
Registered
Join Date: Apr 2009
Location: Denmark and hopefully some place nice
Posts: 1,852
Likes: 0
Received 1 Like
on
1 Post
Ricky
Sounds to me like you are running way too much pitch. Are your engines car engines? The reason for my question, is that sometimes carstuff works poorly on boats. If your props are with cup, try a set without cup, they bite less. Your set would run about 63-66 mph, and that is not realistic. 2.0 gears will get you 48-50 mph, so go from there, and try props with and without cup in 22-26 inches of pitch.
You need those turbo's to spool up.
Sounds to me like you are running way too much pitch. Are your engines car engines? The reason for my question, is that sometimes carstuff works poorly on boats. If your props are with cup, try a set without cup, they bite less. Your set would run about 63-66 mph, and that is not realistic. 2.0 gears will get you 48-50 mph, so go from there, and try props with and without cup in 22-26 inches of pitch.
You need those turbo's to spool up.
Last edited by A.O. Razor; 11-02-2009 at 02:25 PM.
#3
Offshoreonly Advertiser
Offshoreonly Advertiser
The gear ratio change is going to be a neccesity. The ratio change is good for about 5-6 inches of pitch. This still won't get you to the 5500 mark. However the turbo is going to play into this situation. I wonder if there is something else going on with the engines here?
Brett
Brett
__________________
Brett Anderson / BBLADES Professional Propellers
920-295-4435 http://www.bblades.com/
[email protected]
Brett Anderson / BBLADES Professional Propellers
920-295-4435 http://www.bblades.com/
[email protected]