Transome height

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Hi
What should transome height be for an XL shaft outboard?
Keel to engine support.
transome angle is 14 degrees

[tom28571]

The cavitation/ventilation plate on the lower unit should be approximately at the level of the hull bottom. Lower than the hull works fine but introduces more drag. Higher than the hull introduces a greater possibility of ventilating the prop in waves and turns.

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Originally Posted by tom28571

The cavitation/ventilation plate on the lower unit should be approximately at the level of the hull bottom. Lower than the hull works fine but introduces more drag. Higher than the hull introduces a greater possibility of ventilating the prop in waves and turns.

Thanks for respond but is there a standard height on L or XL shaft outboards and a standard height for transomes on production boats?
What is the effect of performance between a L or XL on a particular same hull.
In style a XL be high and looks more powerful but will it affect stability in turns?
Cutout at transome be also smaller.

[marshmat]

Short: 15" nominal.
Long: 20" nominal.
X-long: 25" nominal.
Some bigger OBs also offer a 30" shaft.
The motor shaft will actually be about 1" longer than nominal, from bracket to plate. The transom should be about nominal, measured vertically.
Any given transom configuration will only work with one length. You can usually play with the mount height an inch or two to get things set up smoothly, but you can't use a short shaft engine on a long shaft transom. (If you mount too short a shaft, you will at best ventilate the prop and have no useable power; at worst, you will suck air into the coolant lines and blow the engine.) Too long a shaft will still run, but there will be a lot of extra drag and the boat will perform very poorly.