Classic Mako!!!
Hoping a few members can chime in on a good solution. I am running a 1979 236 mako inboard with a Volvo penta aqad40b. My velvet drive is 2 to 1 and I have been changing props left and right to find the magic prop.
My first prop was a 4 blade 17 x 18 (cup unknown) which pushed the boat along at 17/18 mph @ 2800rpm and 24/25 mph WOT. A sand bar ended that prop, shaft etc.
After some repairs, I ran an 18x17 4 blade (cup unknown) and my performance dropped drastically. I now cruise at 15/16 mph and WOT is 22/23 mph.
Not satisfied with the slow boat, I called ACME and they sent a 18x20, which I caused the boat to blow a ton of black smoke and took awhile to get up on a plane. My WOT went to 25/26, but I lost 500rpm and my cruise at 2.800 rpm was 18/19.
Sent it back to acme and against my wishes they wanted me to try a 18/17 to get back to max rpm. SO my performance numbers dropped back down to prop #2, which only cost $180 vs. the $1,000 from acme.
At this point I am at a loss. I want to try and get the boat as fast as possible at cruise rpm and am hoping this number to be closer to 23/24/25 mph. Does anyone have any suggestions or run a similar rig?
Thanks!
Joe
Hoping a few members can chime in on a good solution. I am running a 1979 236 mako inboard with a Volvo penta aqad40b. My velvet drive is 2 to 1 and I have been changing props left and right to find the magic prop.
My first prop was a 4 blade 17 x 18 (cup unknown) which pushed the boat along at 17/18 mph @ 2800rpm and 24/25 mph WOT. A sand bar ended that prop, shaft etc.
After some repairs, I ran an 18x17 4 blade (cup unknown) and my performance dropped drastically. I now cruise at 15/16 mph and WOT is 22/23 mph.
Not satisfied with the slow boat, I called ACME and they sent a 18x20, which I caused the boat to blow a ton of black smoke and took awhile to get up on a plane. My WOT went to 25/26, but I lost 500rpm and my cruise at 2.800 rpm was 18/19.
Sent it back to acme and against my wishes they wanted me to try a 18/17 to get back to max rpm. SO my performance numbers dropped back down to prop #2, which only cost $180 vs. the $1,000 from acme.
At this point I am at a loss. I want to try and get the boat as fast as possible at cruise rpm and am hoping this number to be closer to 23/24/25 mph. Does anyone have any suggestions or run a similar rig?
Thanks!
Joe
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