Bertram 20 remod question???

[Outcast]

I am looking for some info from someone that has some qualified answers to my weight distribution questions for a redo on a 20 Bertram:

Here is what I have done

Removed V-8 and outdrive approx 840lbs

Adding bracket and 225 4 stroke approx 520lbs motor and 185lbs bracket (keep in mid that the bracket is a positive flotation bracket that allows 250 lbs flotation)

Moved batteries to front (100lbs)

enlarged fuel tank from 50 to 85 gal and moved 2 feet forward

added 12 gal fresh water tank forward of fuel tank


ANy ideas or thoughts will help

Kurt

[jsh]

Kurt:

The weight distribution is managed with the weight estimate, measured in ft-lbs,based on a common origin. When you know the position of the center of gravity for and aft (LCG) you can compare it to the center of buoyancy and get a feel for your static trim.

Determining the center of buoyancy requires the designers knowledge or you must measure the hull and do some calculations. There is a method described in Dave Gerrs Propeller Handbook.

Once displacement , center of buoyancy, and longitudinal center of gravity are known then you can quantify your changes.

I am working on an inboard conversion to a stretched version of the bertram 20.They were built on license here in the 70's someone splashed the original and stretched the 20 to 22 and the 25 to 28.
john