Estimating CG Shift with Heavy Engines

[Capt Terry]

Originally Posted by jorgeinmiami

So on a 20 master angler with the original 70 gallon tank a smaller center console batteries up under the console t top etc.... What would I need to move console up if I put a 140 Suzuki 140 4stroke. Hanging on the transom? Seems like somewhere around 5"????

Jorge- Hey man, I put the CG estimating tool together, you want the answer at the back of the book too? This tool took more time than I will admit; my wife kept asking me if I was still working on it. The math & science part of it was the easiest, then the writing/rewriting to try to get it simple & clear, followed by the time & trouble to get it into CSC without fouling up the formatting of the tables.

SIMPLE ANSWER
Don't know what your engine weighs (check the internet). But let's say it's 200# more than the original & without a bracket assume it's CG is 0.5' aft of the transom, This results in a negative 100 Ft.Lbs. about the reference point of the transom. To compensate for this you want an additional positive 100 Ft.Lbs. added forward of the transom. If the console weighs 100# and that's the only thing you will relocate then you will move it forward 1' If two batteries are moving with the console, let's say that's another 100# (you can weight them), then the total 200# would only to need to move 0.5'. Without a bracket the change is not so severe, probably better off with a cooler of beer between the console & the bow.