Inboard alighnment

Hi, I have a 25' Delta with a 9'6" beam made in Port Canaveral Fl that is just I'm converting into a inboard. The boat weighs in at 6600 without the engine which is a 454 Crusader (1100 lbs). I'm trying to determine two things: How do you determine the center of gravity of the boat so that I avoid mounting the engine to far forward which will cause the boat to plow through the water? Second question is how do you determine the down angle of the shaft, i.e engine angle? I have a Velvet Drive Transmission that is directly coupled to the Crusader.

Thanks

 

On that 25 foot hull, you're going to be pretty well limited by the length of the drivetrain as far as engine placement goes. On my 26, I have transom mounted rudders, very short shafts, MAYBE 3 inches from the stuffing boxes to the coupling flange. The front of the engines are about amidships, right up against the aft cabin bulkhead (I presume your Delta is a flybridge? All the ones I've seen are). Anyway, this results in the boat being a little "squatty", but a little trim tab takes care of that. Mind you, I have twin screws, small blocks at about 800# a piece, so 500 more than yours, but an identical boat to mine has a single mounted exactly the same as mine and runs well. Hope this helps, and good luck with your project! Keep us posted!

 

Inboard Alignment

Thanks Craig, I was able to look at another Delta today that has a inboard 351 and the front of the engine is about 8' from the transom, dead center. He said his boat planes nicely with the flybridge setup. I have a forward cuddy but no flybridge so it's a little lighter. I also have 12"x24" tabs that will help. I think your right about engine placement. Thanks

 

most inboards are 10-12 degrees. (hydros get it down to 7 or so.) the angle will be determined by what strut you use. the tranny flange coupling SHOULD align within 0.003 to the shaft flange or you'll have a vibration problem and premature wear.