Rdegeo4140

I've repowered from a 350/260 alpha to a 496/375 Bravo 1. I'm told that I've put the boat out of balance. It has been recommended to add 250#'s under VEE berth. Does anyone have any idea if this is true. So far I've put 16" tabs and 100 #'s in bow. Still not sure it's right.
I get 4500rpm's out of a 22' pitch Bravo 1 after tuning and 54mph.
I'm new to this power. Any help appreciated.
Happy Captain Bob

Bill272

I don't know if I'd have any answer for you, but what's it doing differently from before the swap??

Audiofn

First off I would ask what does the boat handle like? Does the bow come up high? You may not need the weight up there. Personally I would try and run it with out the weight. If you are getting to much lift from the bow then maybe try a clever prop. This will give you more stern lift and less bow lift. I would play with props a lot before I sarted to add weight to the bow. But then again I have driven Hydrostreams since I started to boat so I like the bow to be light

Jon

mcollinstn

Do NOT add 100# to the bow, unless she is wearing a thong. Boat should perform better AND you should enjoy the ride more if she sits next to you, though.

Rdegeo4140

The boat was pounding alot, landing on stern. I've added the 16" tabs and they seem to help alot.
I put 100#'s of lead in the water bottle. Boat seems to sit better in water.
Also I tried the 100pounds in a one piece. Became a real pain in the ass. Wife wouldn't be happy either if she knew.
I'm new to this power and speed. I need to find someone with experience to show me what this boat can do.
Thanks Everyone,
happy Captain Bob.

Audiofn

Are you pounding because you are light in the bow or becaue you are going faster

Rdegeo4140

Pounding caused by stern dropping first. Hitting amidship instead of slicing with bow. This has improved. Use to keep 9" tabs @full deflection, now only 6-7% w/16". I was told by a supposed offshore racer that he used a water bladder in bow to adjust attitude.
Also I can trim drive out out only 2.5 - 3% before she starts porpoising. I don't know if this is just a step to higher speed and will stop so I trim in again. Again ....lack of experience.
I'm told that Formula would have put a smaller fuel tank moved forward( a 110 vs my 133gal). My boat is rare. It's a 242 LS Hull with a SportFisherman Deck. A242 LS had a 110 gal fuel tank and in later years even had twin 350/260 engines.
Because this setup wasn't available in 1984 Formula has been little help.
Thanks Again
Happy Captain Bob

boatinbill

I would definetly try some different props, the Hydromotive props have the most stern lift, or you can add cup to the Bravo props to get more stern lift. Four blades generally have more stern lift than three blades.

You could also try moving the battery(ies) up under the V berth as this not only puts weight up front, but takes weight off the stern.

If you have a water tank up front, try filling that and see if that makes it ride better.

Its all about the Center of Gravity in the boat, moving existing things forward should have an overall better effect than adding weight.

THings such as the anchor, cooler, etc could be put in the cuddy when under way.

my .02

Rdegeo4140

Thanks for input Boatinbill. I have a Bravo1 4blade on the boat now. It was during blueprinting of prop($450) that it was recommended to add weight to bow. He increase rpm's by 500 without changing pitch. Great job.
I stripped boat of all excess weight and do keep everything still onboard in cuddy. Please note water is only 30#'s for 5gal....Lead 720#'s.
Thanks
Happy Captain Bob

blown formula

I would think there was some similarity between your hull and my 93 252SS....includes swim platform making it a true 24 footer. With a 300hp BB it ran only 52 mph max & was kinda heavy in the bow. Added more HP (650 total) used a Bravo 26" & it carried the front end very good. The stern got a little lite at max speed (75) but the ride was much improved cruising from 45 on up due to a higher bow attitude. I only had 12" Bennet tabs. I think your trouble may be in the prop selection not in the engine change.