454 in a 21' bowrider

[chambers1517]

So I have a Mariah with a 454mpi and bravo 3. I was thinking since the 454 has 310hp and a 350mag has 300 would my boat actually perform better with the 350 mag since it is lighter? Am I actually gaining anything with the 454 and why would Maruah offer this in a 21' boat?

 

[alldodge]

If you have a 454Mag MPI then you have 385 HP at the prop

If it's a 454 MPI which would be 310 HP L29 at the prop

A 350 Mag MPI is 300 HP at the prop

So if your going from a L29 to a 350 MPI then the less weight will help regular running around. If you pull skiers or haul heavy loads you will have trouble getting up. Even with lighter loads you will still be slower getting up.

HP is great for over all speed, but nothing belts low end torque for getting it up (so to speak)

 

[chambers1517]

If you have a 454Mag MPI then you have 385 HP at the prop

If it's a 454 MPI which would be 310 HP L29 at the prop

A 350 Mag MPI is 300 HP at the prop

So if your going from a L29 to a 350 MPI then the less weight will help regular running around. If you pull skiers or haul heavy loads you will have trouble getting up. Even with lighter loads you will still be slower getting up.

HP is great for over all speed, but nothing belts low end torque for getting it up (so to speak)

It's the 454mpi not the mag.

 

[04fxdwgi25]

I have the carbed 454 Mag w/ B3 in my 220 cuddy. To be perfectly honest, I believe the boat is way over powered, for what it is. The big plus is ability to pull a large load behind (like more than 1 skier or a big tube) and get up on plane very quickly.

It's fun, but can only "have fun" with the power when the Boss isn't with me. After hitting 45 mph, she freaks and there is a whole lot of throttle left.

 

[jimmbo]

I would go for the Big Block, as It is easier to get Torque with Cubic Inches than trying to make it with Cams, Compression, Carbs, etc. Plus it is making the Power at a Lower Rpm. Higher Horsepower for a Given Displacement, means weaker Low and Mid Rpm Torque

 

[Scott Danforth]

if you want more power, there is a whole lot that can be done to the L29 to get you about another 75hp easy for not a lot of money.

 

[JASinIL2006]

What's the weight difference... about 200 pounds... Equivalent to one large, full grown adult male?

My 19' bowrider has a 350 Mag and can pop a skier up out of the water like nobody's business. I can't imagine what a 454 in 21' boat could do.

 

[Scott Danforth]

remember, its torque that gets the boat out of the water, not HP.

Torque is how fast you get out of the water
HP is how fast you get down the lake

 

[stresspoint]

there is no replacement for displacement , go with the big block depending on boat weight and what you do with it..

if you want economy then you cant go past a 5.7,

a stroker 383 small block will get you in the same hp region as the big block but the torque is not as muck, however the compensation of less engine weight would probably just about round it off , cant help with fuel consumption figures, i think the 383 would win hands down on the big block .even with the higher RPM required in situations where the big blocks shine.

sum up , big block is a good choice for heavy boat .
383 is a good all rounder choice IMO.
5.7 350 will get you there and back with good economy.

horse power = how fast you hit a wall
torque = how far you go into the wall.

 

[chambers1517]

there is no replacement for displacement , go with the big block depending on boat weight and what you do with it..

if you want economy then you cant go past a 5.7,

a stroker 383 small block will get you in the same hp region as the big block but the torque is not as muck, however the compensation of less engine weight would probably just about round it off , cant help with fuel consumption figures, i think the 383 would win hands down on the big block .even with the higher RPM required in situations where the big blocks shine.

sum up , big block is a good choice for heavy boat .
383 is a good all rounder choice IMO.
5.7 350 will get you there and back with good economy.

horse power = how fast you hit a wall
torque = how far you go into the wall.

So I have a Mariah with a 454mpi and bravo 3. I was thinking since the 454 has 310hp and a 350mag has 300 would my boat actually perform better with the 350 mag since it is lighter? Am I actually gaining anything with the 454 and why would Maruah offer this in a 21' boat?

 

[Scott Danforth]

unless the BBC needs a complete rebuild, I would just go boating.

when it does, look into the 6.3 aluminum heat exchanged LS / LT variants out there. 430+ hp and 400# less weight than the BBC, (200# less than the iron SBC)

or build a 550hp BBC

 

[chambers1517]

unless the BBC needs a complete rebuild, I would just go boating.

when it does, look into the 6.3 aluminum heat exchanged LS / LT variants out there. 430+ hp and 400# less weight than the BBC, (200# less than the iron SBC)

or build a 550hp BBC

I actually have a jeep that I did an ls3 swap on.