Hello,
Im the current owner of the blue 28OR posted here some years back.
Bear with me and read through if you interested and might be able to help.
I started to rig this boat this year with 2x300 Evinrude g2.
Lots of engine faults, steering faults etc during the year, boat coming up and down from the water for repairs and adjusting.
Long story short... boat was on the water again this week, But still does not operate as it should or could.
I do not have any info from previous owners or drivers from the 2x350sci setup, how that handled.
So now I'm reaching out to you, your expertise and hopefully some other activator owners who can provide some inputs that might help.
From here on im not sure at all if its the boat itself that's not handling outboards getting to heavy on the ass, wrong balance, engine heights, trim tabs disturbing the water flow, engine mounting and height and center distance between them or what.
The hull has 10¨¨setback built in.
The evinrudes has a 6´´setback bracket originally.
I'll list what's tested so far and what's not working and working to some degree.
Engine height:
Lowest and second lowest have been tested. On works, one does not obviously.
lowest mounting, provides cooling but makes the boat chine walk like crazy above 45-50kn and torque steers some. NOT drivable at this height, tho it shouldn't be "Too" low?
From pictures the 350SCI engines were boltet like this, but has a different gear case than the g2s.
Lift it one hole up makes it drivable, but cooling do become a problem on one engine until trim tabs and ballast is dialed in perfectly. And then has to be left with these "settings".
A water pickup will probably solve this tho.
Propellers:
Tested some different props with two different engine heights. Overall the boat spins out and the props seems to ventilate gettin on plane, from my understanding so far. I wish it jumped on plane and 2x300hp should be plenty of power, but it just doesn't. it spins out and slips and revs up.
hydromotive 4 blades 30*, lowest engine mounting
Spins out, hard to plane, low speed, bad match
Bravo 28 std
Decent grip on plane, tops out at 65kn ish, a but unstable, porpoises some. Max rpm
Bravo 32 lab finish, short tube, lowest engine mounting
Spins out, hard to plane, chine walks above 45kn, undriveable
Surprised these didn't work when the 28 std did and I was hoping these would beat the Max 5s.
Cutting edge 5 blade, 14,75 dia, 30. Lowest engine mounting and second lowest.
spins out, hard to plan, Best cruise speed,
Max 5, 29,5 short tube, lowest engine mounting and second lowest
Spins some, but gets boat on plane ok
Best overall, best acc, Highest top speed with 68-70kn and full boat, max rpm.
From all of these the max5 are the only useful ones with engine height on second hole.
Seems the boat needs bigger diameter and/or more blades to get on plane.
The standard bravo provided this and with a longer tube and flare, and the max5 gives better grip.
Trimtabs
its mounted tabs after the boat was raced with the 350scis. I do not know why.
But to me it seems they just add more back on the back and disturbs water flow to the lowers.
Now..
Were thinking about adding manual or hydraulic jackplates to at least adjust height easier. But that will add even more weight on the back. It's obvious now it needs to come up from the lowest setting.
Should the engines come even higher?
On the picture below its on the lowest, and been driven one notch up with max5s.
Should trim tabs be removed, at least test without, in case they are disturbing water flow a lot?
Mod the lower units and make nose cones?
Change engines back to merc or go from twin to singel 400hp+?
Remove outboards and go back to innboard?
Not many outboard activators and maybe the balance is just wrong as is.
Thanks in advance
Im the current owner of the blue 28OR posted here some years back.
Bear with me and read through if you interested and might be able to help.
I started to rig this boat this year with 2x300 Evinrude g2.
Lots of engine faults, steering faults etc during the year, boat coming up and down from the water for repairs and adjusting.
Long story short... boat was on the water again this week, But still does not operate as it should or could.
I do not have any info from previous owners or drivers from the 2x350sci setup, how that handled.
So now I'm reaching out to you, your expertise and hopefully some other activator owners who can provide some inputs that might help.
From here on im not sure at all if its the boat itself that's not handling outboards getting to heavy on the ass, wrong balance, engine heights, trim tabs disturbing the water flow, engine mounting and height and center distance between them or what.
The hull has 10¨¨setback built in.
The evinrudes has a 6´´setback bracket originally.
I'll list what's tested so far and what's not working and working to some degree.
Engine height:
Lowest and second lowest have been tested. On works, one does not obviously.
lowest mounting, provides cooling but makes the boat chine walk like crazy above 45-50kn and torque steers some. NOT drivable at this height, tho it shouldn't be "Too" low?
From pictures the 350SCI engines were boltet like this, but has a different gear case than the g2s.
Lift it one hole up makes it drivable, but cooling do become a problem on one engine until trim tabs and ballast is dialed in perfectly. And then has to be left with these "settings".
A water pickup will probably solve this tho.
Propellers:
Tested some different props with two different engine heights. Overall the boat spins out and the props seems to ventilate gettin on plane, from my understanding so far. I wish it jumped on plane and 2x300hp should be plenty of power, but it just doesn't. it spins out and slips and revs up.
hydromotive 4 blades 30*, lowest engine mounting
Spins out, hard to plane, low speed, bad match
Bravo 28 std
Decent grip on plane, tops out at 65kn ish, a but unstable, porpoises some. Max rpm
Bravo 32 lab finish, short tube, lowest engine mounting
Spins out, hard to plane, chine walks above 45kn, undriveable
Surprised these didn't work when the 28 std did and I was hoping these would beat the Max 5s.
Cutting edge 5 blade, 14,75 dia, 30. Lowest engine mounting and second lowest.
spins out, hard to plan, Best cruise speed,
Max 5, 29,5 short tube, lowest engine mounting and second lowest
Spins some, but gets boat on plane ok
Best overall, best acc, Highest top speed with 68-70kn and full boat, max rpm.
From all of these the max5 are the only useful ones with engine height on second hole.
Seems the boat needs bigger diameter and/or more blades to get on plane.
The standard bravo provided this and with a longer tube and flare, and the max5 gives better grip.
Trimtabs
its mounted tabs after the boat was raced with the 350scis. I do not know why.
But to me it seems they just add more back on the back and disturbs water flow to the lowers.
Now..
Were thinking about adding manual or hydraulic jackplates to at least adjust height easier. But that will add even more weight on the back. It's obvious now it needs to come up from the lowest setting.
Should the engines come even higher?
On the picture below its on the lowest, and been driven one notch up with max5s.
Should trim tabs be removed, at least test without, in case they are disturbing water flow a lot?
Mod the lower units and make nose cones?
Change engines back to merc or go from twin to singel 400hp+?
Remove outboards and go back to innboard?
Not many outboard activators and maybe the balance is just wrong as is.
Thanks in advance
