What size engine

[tommays]

Fo<br />i dont think you go to big but fitting a big block in your engine area could be a problem<br /><br />what kind of HP do you have now many of the EFI 5.7 motors put out a lot more power than older carb motors without the weight and size problems<br /><br />tommays

 

[formulafisher]

What size engine

Hello i have a 23ft formula center console the boat weights about 5000lbs and has a very deep v hull. I am getting ready to repower the boat and wondering what size engine i should go with. It is currently powered by a 351 the boat isnt performing how i would like so i am prepared to buy a whole new drive and all i just need to know how big i should go. Any suggestions would be helpful

 

[Bondo]

Re: What size engine

My Personal formula for determining How Much Horsepower is to buy All you can Afford.......<br />Then figure out how to Stuff it into Place........ <br /><br />There's No Such Thing as an Over-Powered Boat..........................

 

[formulafisher]

Re: What size engine

Im told the 351 is putting out about 250hp the boat isnt performing it tops out at around 26mph gps

 

[JasonB]

Re: What size engine

My guess is that with that 351, you are running an OMC drive of some form unless this is a '73-'77 boat, all assuming stern drive.<br /><br />Any consideration of rebuilding the 351? They are great engines when in good form. Soundls like yours may need a refresh. I have a 302 that pushes my 19' deep V to near 50 on a good day with 2 large adults. It would save you teh headaches of trying to rig for a GM block motor.

 

[Don S]

Re: What size engine

All you need is this..........and bunches of money <br />I want one myself.......<br /><br /> Volvo Penta 5.7Gxi DP <br /><br />

 

[formulafisher]

Re: What size engine

the engine is coupled to a alpha one the engine has only about 500hrs on it but it doesnt have the power to push the boat to the speed i would like.

 

[JasonB]

Re: What size engine

I like Don's idea, but the price is too steep for my pocket.<br /><br />Your 351 can be built up easily, but it's my understanding that your drive is only rated to 300hp, or if like my pre-alpha, rumor has 275hp. Merc only used Ford engines from '72 to '77 or so.<br /><br />Are you sure your boat hasn't picked up some weight like wet foam or something?<br /><br />I would think 250hp would perform better on that boat as mine weighs about 3200-3400lbs loaded. Have you considered sealing the transom and hanging an outboard on the transom? Just a thought.

 

[waterone1@aol.com]

Re: What size engine

In my opinion there are so many variables that contribute to top end speed on a boat,and the one you cannot get away from is the hull design. Of course the question of any repower/ upgrade.... is it worth it ? I just ask that you really think this through before "diving in". If money isn't an issue, and you don't care if you re-coup your investment, then by all means, upgrade to a new power and drive package like the one Don posted. The truth is packages like that are putting out the same horsepower as a big block did a few years ago. The other thing (you did not state the year of your boat) is the design of the hull, some designs require more power than others to move. 50-60 horsepower more will make an improvement, but will it make enough of one to make you happy ? Perhaps it's time to think of a different boat. Just my 2 cents worth.

 

[formulafisher]

Re: What size engine

this hull is a very deep v the boat rides amazing. Its only 23ft but i have had it out in stuff most people wouldnt take a 30ft boat out in the hull was built like a tank there is no way im getting rid of this boat

 

[tommays]

Re: What size engine

Fo<br />at 26 mph you have a motor problem or a wet heavy boat problem i would try to be sure which before going futher<br /><br />just wondering have you owned the bost a long time and if it was allways this slow<br /><br />tommays

 

[formulafisher]

Re: What size engine

I have had this boat for about 10yrs and it has always been this slow.

 

[paulrfrancisco]

Re: What size engine

10 years of ownership and always this slow... Either the boat is waterlogged, the motor is tired, or the prop is inadequate. It sounds like the motor may not be too bad or at least hasn't gotten worse and worse over 10 years of use... and seasonally, I would thisn the boat would dry out some from fall to spring... <br /><br />Are your RPM's getting to the specified maximum? maybe you are over propped... does the motor sound like it labors at WOT..?

 

[paulrfrancisco]

Re: What size engine

maybe your carb is way too lean...

 

[JasonB]

Re: What size engine

Wet foam doesn't dry very well, even in a warm, dry storage. As others have asket, what are your R's, and have you weighed the boat lately?

 

[formulafisher]

Re: What size engine

the wot rpms are at 4300 rpms. i havnt weighted the boat that is going to be something i do in the spring

 

[paulrfrancisco]

Re: What size engine

I cant say for sure, but 4300prm seem a bit low... you may be over propped... should be probably about 4600-4800. Does anyone know the specs?

 

[16Pilot]

Re: What size engine

How much are they Don?

 

[Don S]

Re: What size engine

I don't do prices, but I think the package alone is $15K +<br />depending on options. But please, don't quote me on it till I find out for sure.

 

[JasonB]

Re: What size engine

4300 is right by factory Mercruiser spec for the 302 and 351. I think the recommended range is 4200-4400.