I/O (Sterndrive) Conversion to Outboards

[tpenfield]

I might add that going stern in and departing with a 15 mph crosswind was a bit challenging. The joystick was well worth it.

 

[tpenfield]

Here is a design thought that would have extensions (wings) either side of the engines to provide better stern access.

The Regal OBX is a good example of the design.

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In terms of a bracket with such features, it might look something like this.

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I'll just have to see how the dimensions and geometry all works out.

 

[tpenfield]

Quick update . . .

In my research, I came across a bracket that was made for a Chaparral 327 SSX, which is essentially Chaparral's version of my boat ( mid-cabin bowrider). The Admiral and I looked at a 327 SSX when we were shopping for the CY338. The Chappy got a thumbs down from the Admiral because of an awkward cabin layout which would result in frequent head-banging. I gave it a thumbs down for the raw water cooled engines.

Anyway . . . here is a link to the bracket and some pictures . . .
https://weldingworldinc.com/collect...m-high-flotation-twin-outboard-engine-bracket
About $9K with shipping, which is a good reference point for my planning/budgeting.

The Chappy bracket is a bit small for my boat, but the concept is about the same, except for attaching the top of the bracket to the underside of the platform.

I'm not sure if there is a significant reason that one would not want to provide some attachment to the swim deck, but something to consider pro's/con's of doing such. Perhaps an issue of trapping water in between the top of the bracket and the underside of the swim deck. I might alter my design accordingly and go with an easier approach.


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About a 2-3" air gap between the swim deck and the bracket . . .

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I also noticed in the description, that 6061 T6 and 5052 H32 aluminum were used in fabricating the bracket. It seems like 6061 is a step up from the 5083 aluminum used in some brackets. @Scott Danforth , any comments on the type of aluminum and the air gap?

 

[Scott Danforth]

5083 / 5086 is marine plate. 6061 is cheaper industrial plate. 5052 is soft for covers and non structural stuff.

5083 is preferred as it looses less strength in the HAZ (Heat-Affected Zone) from a design standpoint. however the material is 2X the cost of 6061.

Not until entering the recreational market would I ever have considered 6061 in a marine environment. however its cheap.

 

[dingbat]

Not until entering the recreational market would I ever have considered 6061 in a marine environment. however its cheap.

Copper is added for strength and improve machining properties. No good for saltwater environments.

T = tempered. Don't bend…cracks

 

[tpenfield]

Thanks, guys. 5083 it is.

To me the price of $9K-ish seems pretty steep, if they are using less expensive material.

 

[Scott Danforth]

They are probably making 50 points on margin

 

[Scott Danforth]

Back to my suggestion of finding a local fabrication shop

 

[dingbat]

Thanks, guys. 5083 it is.

To me the price of $9K-ish seems pretty steep, if they are using less expensive material.

You can't bend 6061.

The money you save in materiel using 6061 (roughly 20%) is a drop in the bucket to the difference in fabrication (welding) costs