X dimension=Square root of:

(Camshaft to Crankshaft^2)*(Crankshaft-Propshaft^2)-(keel to oil pan^2)+(lenght of waterline+windsheild Height)/(lenght of boat trailer +number of wheels)-(Tounge weight in kilos+name plate capacity in lbs-saftey equipment weight)+(minum octane rating * % of solid fiberglass of hull+amount fuel burn during 90 second wot blast)

Haha.

looks Like DerekandKathy nailed it? With all the talk about drive to keel I never thought about it that way. Good to know...

I always wondered why it was dubbed X-Dimension and not Y-Dimension. Conventional wisdom would imply that any measurement along an X axis would be one that is lateral. The Y axis is most commonly associated with a vertical dimension or measurement.

Sq. Rt. of (5.150^2)(21.8125^2)-(17^2)+(312+18)/(32+4)-(409+2400-113.72)+(89*86.3+1.99) = 131.63049

Asuming it's a bravo boat, trailer full of blinker fluid, and ceramic muffler bearings

No,,,,, that's the sex-dimension. Sometimes also refered to the boats entertainment value, as measured pr. square inch.

It's called x- dimension because an azzhole like me dubbed it that.....

Yes, the X dimension is controlled by the engine height.
If you put on a shorty drive, the actual X dim does not change, but he propshaft height does change.

Thanks Griff. So on a twin how would one go about measuring? From crank to bottom of keel? V hull no notch.

And what might be the optimal measurement for propshaft to bottom no boxes?

J you measure from crant to the bottom of the hull directly under the crank, not the keel. It is always measured perpendicular to the crank, no matter the number of engines ect. There is no optimal x as such, it depends on what you want to do. Many twins today run between 17" and 19" in B1 applications. Some a bit less, some a bit more. It also depends on whether the manufacture set it up with shorties and/or boxes from the beginning. When talking drive x-dim, it refers to the distance from input to output shaft.

See some expereinced boaters are learning somthing. From reading what others have talked about in the past I thought it was tottally related to prop shaft height but turns out prop shaft height is just relalted to x dimension and it depends on the length of the drive.