I/O (Sterndrive) Conversion to Outboards

tpenfield

tpenfield

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I got the 5 gallon pail of VE resin, but the delivery person must be holding my 1708 cloth hostage or something. Awaiting a ransom letter. . .

Meanwhile . . . I have taken a look at the transom. Flatness, height, bolt positions, etc.
.
Honda-BF350-Flatness-1.png
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Flatness: I am thinking that I could use the cut-out pieces of Coosa from the transom along with some fiberglass putty to make/form a flat area (red dotted line)

Transom/Engine Height: By my best measure . . . the top of transom is 30.5" above the planing surface at the mounting point of the outboards. The spec. of the shaft length is 30.1" . . . making the ventilation plate a wee bit (0.4") above the water stream. There is a 'rule of thumb' when extending the outboard on a bracket . . . 1" of engine height for every foot of bracket extension. I asked about the science behind this 'rule of thumb' on another forum and a bar-room brawl ensued. :ROFLMAO:

My splashwell bases block the lower position on the top series of holes. That should not be a problem, as the upper holes are what matters. FYI - The BF350 gets 2 top bolts on each side (i.e. 4 bolts) and then 2 lower bolts in the slotted area.

In my on-water testing after 'splash day', if it looks like I need to raise the engine, I can probably get 0.5-1.0" inch without any problem.
 
alldodge

alldodge

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tpenfield said:
I got the 5 gallon pail of VE resin, but the delivery person must be holding my 1708 cloth hostage or something. Awaiting a ransom letter. . .

Meanwhile . . . I have taken a look at the transom. Flatness, height, bolt positions, etc.
.
View attachment 415305
.
Flatness: I am thinking that I could use the cut-out pieces of Coosa from the transom along with some fiberglass putty to make/form a flat area (red dotted line)

Transom/Engine Height: By my best measure . . . the top of transom is 30.5" above the planing surface at the mounting point of the outboards. The spec. of the shaft length is 30.1" . . . making the ventilation plate a wee bit (0.4") above the water stream. There is a 'rule of thumb' when extending the outboard on a bracket . . . 1" of engine height for every foot of bracket extension. I asked about the science behind this 'rule of thumb' on another forum and a bar-room brawl ensued. :ROFLMAO:

My splashwell bases block the lower position on the top series of holes. That should not be a problem, as the upper holes are what matters. FYI - The BF350 gets 2 top bolts on each side (i.e. 4 bolts) and then 2 lower bolts in the slotted area.

In my on-water testing after 'splash day', if it looks like I need to raise the engine, I can probably get 0.5-1.0" inch without any problem.
Click to expand...
Maybe discuss with NA but I'm thinking the drive height might benefit higher

Why

Using Crap----erall insight, they have the motor height higher than bottom of hull. The forward power is good, reverse not so much. The motors are set back further so water will come up prior to making contact
 
P

Pmt133

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Jan 6, 2022
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1,460
I watched a guy from bluewater talking about mounting height, he was saying every 10 inches back from the end of the running surface they move them up an inch or so as a "rule of thumb" Since the running surface is being extended here, they may not end up being "up" all that much.

I'd imagine you want the AV plate around the surface. My drive is completely buried at wot but I can't easily fix that... tis a wee bit more difficult with an I/O.
 
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