Engine change out ballast problem

[glueman90]

1987 Carver Mariner 36'. In 2008 the engine were replaced with rebuilt twin Detroit's 4-53 140 hp,rebuilt trans and V-drives. New shafts, cutlass bearings and genny. The old owner lost interest and sold it to a guy who know nothing about boats he screwed up a lot of stuff. He only put on 400hrs on the boat moving at 10 mph. The props were way out of pich. There now set as 4 blade 22" X 25 pitch with a med cup. I have spent the last year putting the boat in working order.

My questions is the rebuilt Detroit's are a lot heaver the the gas engines and it sets very heavy to the Stearn. The bow sets pretty high from what it should be. I am guessing about about a 12 to 15" to where the water line should be. When I try to get the boat up on plane the tabs are all the way on for bow down and the bow just keeps on rising and the Stearn just digs a hole.
I am pretty sure I need to add ballast to the bow but I don't know how much to add and do I need to increase the size of the trim tabs?
I am hoping that some of you old salts can help me with this issue.
Thanks
Dave
Palm Coast Fl.

[bud37]

Welcome to the forum....I don't know about an old salt...but, IMO you only have 280 HP total, fairly heavy boat ,I don't think there is enough raw power to plane regardless of what you do, ballast would equal more weight. Sounds like the original owner was creating a real low cost trawler like set up.....7 or so knots, trouble is , you have a planing hull and hull speed is somewhere around 7knots so anything past that is pushing water.....you could check with a prop shop and maybe optimize what you now have.Hope this helps, remember just my opinion here........

[nightsky]

First off make sure the engines are able to achieve WOT. If not, re pitching props in order. Ballast and larger trim tabs will help. You can try moving weight from stern to bow such as batteries or empty the stern water tank and add water tank or bladder up forward of equivalent size. These can change trim without adding extra weight to a boat that may be already under powered.

[mjk1040]

All chain rode on the windless will help some for forward ballast. Water tanks are mid-ship on that model I do believe. Not much more you can move that I can see will help. Maybe the hot water tank to the galley?

[waybomb]

Does your boat still have the stainless steel exhaust assembly on the outside?
On my boat, with full fuel on the 3 tanks and us sitting in back, about half of the stainless exhaust pieces are under water.
How low does yours sit?