center of gravity-triple o/b's
 

I'm getting ready to place 8" jack plates on my 37' Midnight Express center console. It initially was an ex- smuggler and came with quad 200's (same bracket 24"). It now has triple 225 Opti's.

It has four fuel tanks in the floor. One bow, one center (runs from transom forward approx 10 feet and two side port and stbd total 1,000 gallons. I usually keep about 100 g in the center tank and keep the others empty.

The center console is placed way back 8' from transom most cc's this size are 10 from transom.

I plan on moving it forward 18" -24" and also moving the batteries forward.

The bracket does have a large cavity which I may fill with foam floation to help keep the stern higher at rest.

Does any one know how this will effect the center of graivity performance handeling etc.?

Thanks

Re: center of gravity-triple o/b's
 

If your boat handles okay initially, then you want to keep the longitudinal center of gravity position (LCG) the same through any modifications. You can account for everything in the planning stages, then update as you go, just like the shipyards do. The required equation is attached as a picture, and is just a sum of first moments calculation. Make yourself a spreadsheet, and add or subtract each weight multiplied by its longitudinal position. You can see exactly how far you'd have to move the console forward to offset the extra setback of the motors, play with fuel loadings etc.

Re: center of gravity-triple o/b's
 

Thanks for the info. I'll give it a try. :eek: I may be re-contacing you if it's okay.