Q. Factory : 2022 Mercury 565 racing engine.) & ( Mercury 496 Mag H/O bravo one ) boat spd (Q).

[Askem]

Say Hello to my new friends out there. I could use a little help !!! I'm repowering a 2005 campion 700 chase. ( serial # ZBI70001G405.) motor removed Mercury 496 Mag H/O SERIAL#( OWO60052 ) Ok, here's what Ive been told by two seperate engine suppliers. repowering your boat with the the new Mercury 565 engine will still only give you about 60 - 63mph ????? well, what I dont see, is how an engine producing another full 140hp more, than the 496 engine at 425hp " How could this not give you more top end speed" Look forward to any replies Thanks for your time! "Askem"

 

[Scott06]

What does it do with the 496 currently in it?

 

[Bondo]

Ayuh,..... Welcome Aboard,..... When ya get into that range, 140 hp is a tiny jump,......

 

[tpenfield]

140 HP increase from 425 HP would get you about 10% increase in speed by my calculations. So, if you were getting high 50's (mph), you will probably get low 60's with the HP increase.

BTW - you forgot to tell us what the top speed is/was with the 425 hp.

 

[todhunter]

Ayuh,..... Welcome Aboard,..... When ya get into that range, 140 hp is a tiny jump,......

Yep, it costs exponentially more to go incrementally faster

 

[racerone]

It is difficult for some folks to understand what power it takes for boats to go faster !!

 

[Askem]

What does it do with the 496 currently in it?

Hello Scott06, thanks for responding, anyway when I first purchased the boat a 2005 new in 2011. I was getting 70-73 mph driver with full tank of fuel & required vessel safty gear. perfect with scratchless waxed hull! today, or I should say last season, the boats top speed as above mentioned, including hull condition all the same, boat was now permorming at 60-63mph. (note) I had tried effortlessly to regain perchase speed to no avail! injectors replaced, plugs, wires, hull still scratchless waxed & polished, dehumidified inteirior each off season. as well as indoor keeped.

 

[Askem]

Yep, it costs exponentially more to go incrementally faster

Hi, todhunter, is the "reasoning for alought more hp required" do to the amount of weight envolved with both the boats wieght in addition to the engines weight, Hull design or plainly all the above? look forward to your response. Thanks for your time

 

[Askem]

It is difficult for some folks to understand what power it takes for boats to go faster !!

Hi racerone, thanks for the reply. with the expotentail power needed to increase mph is this do to the overall, wet wieght of the boat, motor, & purhaps hull design?

 

[Askem]

Hello Folks, I am repowering my boat hopefully for this season. I'm also trying to pick up more top end speed while im at it, so far I'm unable to put a much larger engine in the boat do to compartment size. My next thought is it relistic to go with a smaller engine that would allow building up that motor with supercharger, procharger what ever else the engine may need internally, with the correct drive attached to handle the increased hp or is this the wrong way to go about it? current boat is a ( 2005 24" campion 700 chase ser # ZB170001G405 ) removed engine was a( 2005 Mercury 496 Mag Ho Bravo one ser# 0W060052 ) Look forward to any replies from all my new friends Thanks again "Askem"

 

[Askem]

Yep, it costs exponentially more to go incrementally faster

What does it do with the 496 currently in it?

60-63mph one person, full wet wieght, flawless well maintained hull.

 

[Bondo]

Hello Folks, I am repowering my boat hopefully for this season. I'm also trying to pick up more top end speed while im at it, so far I'm unable to put a much larger engine in the boat do to compartment size. My next thought is it relistic to go with a smaller engine that would allow building up that motor with supercharger, procharger what ever else the engine may need internally, with the correct drive attached to handle the increased hp or is this the wrong way to go about it? current boat is a ( 2005 24" campion 700 chase ser # ZB170001G405 ) removed engine was a( 2005 Mercury 496 Mag Ho Bravo one ser# 0W060052 ) Look forward to any replies from all my new friends Thanks again "Askem"

Ayuh,..... To save confusion, let's keep all of this in one thread,......

Thank you,....

 

[Bondo]

Hello Folks, I am repowering my boat hopefully for this season. I'm also trying to pick up more top end speed while im at it, so far I'm unable to put a much larger engine in the boat do to compartment size. My next thought is it relistic to go with a smaller engine that would allow building up that motor with supercharger, procharger what ever else the engine may need internally, with the correct drive attached to handle the increased hp or is this the wrong way to go about it? current boat is a ( 2005 24" campion 700 chase ser # ZB170001G405 ) removed engine was a( 2005 Mercury 496 Mag Ho Bravo one ser# 0W060052 ) Look forward to any replies from all my new friends Thanks again "Askem"

Ayuh,...... You'll need a full blown BBC, 'n possibly a different drive to get to the speeds yer lookin' for,.....

To start, you oughta go through the boat, 'n remove any clutter that's gathered over the years,......
Then moisture check the transom, stringers, 'n flotation foam,....

with the expotentail power needed to increase mph is this do to the overall, wet wieght of the boat, motor, & purhaps hull design?

Yes,.... All of it matters,.....

 

[Askem]

Ayuh,..... To save confusion, let's keep all of this in one thread,......

Thank you,....

Sorry about that sir, "computing" is not one of my strong points! I could use a tip or two if possible, the last thing I want to do is irratate anyone involved in this forum. Management team, or it's Members! Sincerly, "Askem"

 

[Scott06]

Ayuh,...... You'll need a full blown BBC, 'n possibly a different drive to get to the speeds yer lookin' for,.....

To start, you oughta go through the boat, 'n remove any clutter that's gathered over the years,......
Then moisture check the transom, stringers, 'n flotation foam,....


Yes,.... All of it matters,.....

Yeah What he said... if you legitimately lost 10 mph you have either added a bunch of weight via stuff (generator or batteries?) or waterlogged hull, or you must have very low compression on engine. I assume the initial 70 mph speed was accurate via gps?

 

[Askem]

140 HP increase from 425 HP would get you about 10% increase in speed by my calculations. So, if you were getting high 50's (mph), you will probably get low 60's with the HP increase.

BTW - you forgot to tell us what the top speed is/was with the 425 hp.

I had purchased a 2005 boat new in 2011. (initially I was getting low 70's ) new injecters wires, plugs, compression test, as well as indoor keeped, radically dehumidified each season. couldnt regain that 10mph! any way before droping a piston last season, the boats top speed, full wet wieght one operater & saftey gear topped out at low 60's

 

[Askem]

Ayuh,...... You'll need a full blown BBC, 'n possibly a different drive to get to the speeds yer lookin' for,.....

To start, you oughta go through the boat, 'n remove any clutter that's gathered over the years,......
Then moisture check the transom, stringers, 'n flotation foam,....


Yes,.... All of it matters,.....

Hello Bondo, Thanks for your reply, could you please give me little more information on what a fully blown BBC, actually is?

 

[Bondo]

Hello Bondo, Thanks for your reply, could you please give me little more information on what a fully blown BBC, actually is?

Ayuh,..... The usual stuff,..... Forged balanced internals, the best heads, tuned headers, super charger, etc,......
probably 'round 50 grand these days,......
Scott Danforth probably could give ya a recipe to build upwards of 1000 hp or so,....
Definitely in the custom machine shop, custom builder category,....
Ya might wanta cruise over to off shore only, 'n see what the go-fast guys are buildin',.....

 

[Askem]

Yeah What he said... if you legitimately lost 10 mph you have either added a bunch of weight via stuff (generator or batteries?) or waterlogged hull, or you must have very low compression on engine. I assume the initial 70 mph speed was accurate via gps?

 

[Askem]

Ayuh,..... The usual stuff,..... Forged balanced internals, the best heads, tuned headers, super charger, etc,......
probably 'round 50 grand these days,......
Scott Danforth probably could give ya a recipe to build upwards of 1000 hp or so,....
Definitely in the custom machine shop, custom builder category,....
Ya might wanta cruise over to off shore only, 'n see what the go-fast guys are buildin',.....

Thanks for the heads up Bondo. I'll let you know how it turns out!