800 HP = 84mph! Is this true?!

[Fltplan]

Just reading through a few threads that were older, but recently updated. New jet boat ran 84 mph. I thought that was pretty cool. Then I saw that it was using 800 hp to do it. I know that jet boats aren't the most efficient vehichles around. Used to have a 19' Miller with a stock 454/325hp that would do 60mph. Does it really take an extra "475" hp to get it to 84mph?

How much would an 800hp motor cost to have built? Not in parts, but just pick it up, 800hp.

What's the fastest you could go with a "small" 500hp motor?

 

[djunkie]

I'm sure it depends on the boat. My 22 schiada v-drive only runs 70ish with 660hp.

 

[Fltplan]

I'm sure it depends on the boat. My 22 schiada v-drive only runs 70ish with 660hp.

That's a prop though, that makes since. That's pretty fast for a bigger boat like yours. My dad used to have a boat similar to yours in your sig, but with a jet and I think it topped out at about 40 mph with a stock 455 Olds, very low on the hp.

 

[Riverbound]

Our stoker 224 was clocked right at 100mph with a merchant 500hp. During the hotboat evaluations.

Sent from my Droid using Tapatalk

 

[Fltplan]

Our stoker 224 was clocked right at 100mph with a merchant 500hp. During the hotboat evaluations.

Sent from my Droid using Tapatalk

jet?

 

[Riverbound]

jet?

No. Jets only do 100 on eBay I/O

Sent from my Droid using Tapatalk

 

[Fltplan]

I get the "hot rod" part of jet boating. Pretty cool to sit in front of the big motor n all. Just can't imagine having someone building me a 800hp motor and getting 84 mph and being happy with it. Different strokes for different folks I know. I would rather have that boat with a 450 hp motor that would do 65ish mph maybe?

I still wanna know how much that motor would cost?

 

[Sleeper CP]

Jets = inefficiency, but it very much depends on the boat and set-up.

820 hp ( observered) at 6,200 = 99.8 with lots of wetted surface:

This was before bottom "blueprinting" boat had hook in it.

If boat were aired out a bit it would run 102+ or so off the bottle. Bare hull weighs 780 lbs, 990 lbs with pump and interior, approx 1,800 lbs running weight.

Look at this pic on the Nos at 109 mph. Approx 1,150 hp @ 6,800. You can see the boat is aired out a bit more:

Boat could be a bunch faster if aired-out, just never wanted to run the boat loose.

S CP

 

[Riverbottom]

Most of my boats are v-drives or outboards, but I raced a comp jet circle boat ( Advantage / Rogers ) it runs around 95 to 98 m.p.h with about 600 H.P.

What kind of boat was it ? How big and how heavy?

Newer Jets are pretty efficent if set up correctly. I have never owned a jet, but after 29 boats, my next purchase will be one. I have explored most of the west coast, and off shore already. I want to spend my time on the rivers in the northwest. I am thinking an aluminium Eagle with a roll cage will be my 30th boat.

 

[white tortilla]

my fam has the same type boat as sleeper cp for the river, it has 830hp and ran 104 on NJBA clocks with me @190 lbs, and full interior and 15 gal of gas.

so 800 hp at 84 sounds like an innefficient hull.

my dads race boat thats a jet ran 124 with 820 hp.

 

[Fltplan]

Jets = inefficiency, but it very much depends on the boat and set-up.

820 hp ( observered) at 6,200 = 99.8 with lots of wetted surface:

This was before bottom "blueprinting" boat had hook in it.

If boat were aired out a bit it would run 102+ or so off the bottle. Bare hull weighs 780 lbs, 990 lbs with pump and interior, approx 1,800 lbs running weight.

Look at this pic on the Nos at 109 mph. Approx 1,150 hp @ 6,800. You can see the boat is aired out a bit more:

Boat could be a bunch faster if aired-out, just never wanted to run the boat loose.

S CP

wow, great info! so what does said motor cost approx? you can send me a pm if it hurts too much!

 

[OCMerrill]

Stopping for Gas, Beer, Ice, and cows slows down the speed average.

Plus side - you get to hear the engine.

My ex BIL Carrera with 550 hp ran 65 mph.

 

[Faceaz]

I'm sure it depends on the boat. My 22 schiada v-drive only runs 70ish with 660hp.

Our 23' cat O/B does 70ish with 300hp.

 

[Sleeper CP]

I get the "hot rod" part of jet boating. Pretty cool to sit in front of the big motor n all. Just can't imagine having someone building me a 800hp motor and getting 84 mph and being happy with it. Different strokes for different folks I know. I would rather have that boat with a 450 hp motor that would do 65ish mph maybe?

I still wanna know how much that motor would cost?

Best bang for the buck on a BBC would come from Rherer and Morrison. 540" at $ 14,000k either 680 hp street engine or 900 hp race engine both at $ 14,000.

http://www.rehermorrison.com/rmEngines.htm

Go to engine section and look at the 540"s

The price to go from 80mph to 90 is a bunch, the cost to go from 90 to 100 mph is just stupid. Ask me how I know

S CP

 

[Fltplan]

The "boat" was the Ultra in the thread still up on "new threads". 22 stealth, not knocking it at all, it's a great looking boat. It's definitely not a race boat, but a family cruiser!?

C'mon someone tell me about the cost of these motors. 20k? 40k? more?

 

[Fltplan]

Best bang for the buck on a BBC would come from Rherer and Morrison. 540" at $ 14,000k either 680 hp street engine or 900 hp race engine both at $ 14,000.

http://www.rehermorrison.com/rmEngines.htm

Go to engine section and look at the 540"s

The price to go from 80mph to 90 is a bunch, the cost to go from 90 to 100 mph is just stupid. Ask me how I know

S CP

Cool link, that actually seems pretty reasonable. How much would the pump behind it have to cost to use that hp?

 

[Sleeper CP]

wow, great info! so what does said motor cost approx? you can send me a pm if it hurts too much!

If you had to build an engine like our 565" 950+ hp single carb Ford today from scratch you're looking at better than $ 18k. It's basically the same engine I've had since '93. Same rods, crank, block. I have two sets of heads. The high compression set has Ti intake valves ( $ 140 ea) and shaft rockers. Stuff like that runs the cost up a bunch as does a killer set of heads flowing 450 cfm's.

I could build a 800 hp Ford for less than $ 12k +/- and still have a pretty stought piece. It might cost a bit more if someone wanted 800 hp on pump gas.

S CP

 

[Sleeper CP]

The "boat" was the Ultra in the thread still up on "new threads". 22 stealth, not knocking it at all, it's a great looking boat. It's definitely not a race boat, but a family cruiser!?

C'mon someone tell me about the cost of these motors. 20k? 40k? more?

22's are big boats for a jet. Big and heavy boat.

There are quite a few jets you could get to run over 100 mph with an honest 800 hp. Set-up is key.

I'm not sure what a complete pump costs today........ maybe $ 4,000 for a super dooper pump ? I'll look at some of my old pm's and see if I saved them.



S CP

 

[Nordie]

my jet with 550 hp, and not really set-up ran 74 mph...its a tahiti to boot!

 

[riverratmike]

gettin' 60mph with 160 hp

 

[Fltplan]

well, I'm trying to get a hold on the cost, not the hp now. I've got a 300XS that is on my 21' Daytona. It goes 92mph with a 28p prop. Could easily pull a 30p, just to drop rpms a little for longevity. I've probably got close to 20k into the motor, hydraulic steering and install.

So, sounds like the cost would be almost the same to get a jet to go the same speed. Obviously, fuel efficiency is another topic. I guess the real test would be what kind of hp would it take to get my Daytona to go 92?

I'm thinking it wouldn't be able to get outta the water so easy with a motor inside. Probably need that 700-800 hp to get it to the same speed, maybe a little more.

 

[woodagain]

Just reading through a few threads that were older, but recently updated. New jet boat ran 84 mph. I thought that was pretty cool. Then I saw that it was using 800 hp to do it. I know that jet boats aren't the most efficient vehichles around. Used to have a 19' Miller with a stock 454/325hp that would do 60mph. Does it really take an extra "475" hp to get it to 84mph?

How much would an 800hp motor cost to have built? Not in parts, but just pick it up, 800hp.

Less than a 300 Merc !!

 

[Fltplan]

Just reading through a few threads that were older, but recently updated. New jet boat ran 84 mph. I thought that was pretty cool. Then I saw that it was using 800 hp to do it. I know that jet boats aren't the most efficient vehichles around. Used to have a 19' Miller with a stock 454/325hp that would do 60mph. Does it really take an extra "475" hp to get it to 84mph?

How much would an 800hp motor cost to have built? Not in parts, but just pick it up, 800hp.

Less than a 300 Merc !!

Looks to be about the same, 15k. Of course that didn't include the prop ($800). That's what I was getting at.

 

[woodagain]

well, I'm trying to get a hold on the cost, not the hp now. I've got a 300XS that is on my 21' Daytona. It goes 92mph with a 28p prop. Could easily pull a 30p, just to drop rpms a little for longevity. I've probably got close to 20k into the motor, hydraulic steering and install.

So, sounds like the cost would be almost the same to get a jet to go the same speed. Obviously, fuel efficiency is another topic. I guess the real test would be what kind of hp would it take to get my Daytona to go 92?

I'm thinking it wouldn't be able to get outta the water so easy with a motor inside. Probably need that 700-800 hp to get it to the same speed, maybe a little more.

Actually, a 21 Eliminator Daytona with a stock 460 Ford 1979 model bone stock from Eliminator would run 65 mph loaded with interior and full motor cover.As you know , once you start airing out ,things will happen.

Built a 20 ft Eliminator open bow tunnel with a pump gas 760 hp BBC that would ski my son at 85 to 88 mph depending on chop or wind.
Still running that motor in my 22 DCB, 12 yrs old since motor built.
Probably spent around $12,000.00 at original motor build.

21 Eliminator -You have the best hull out there!
Hard to out engineer Chevy.

 

[Fltplan]

really like the way mine drives with the 300 on it. I would like to drive a high hp jet in the same hull, just to compare. I haven't really found anything to complain about with my boat and I like "hot rods" too.

 

[Wayne Zighter]

it also does'nt take too many things out of adjustment (timing curve, fuel/air, cam timing, and so on) to make an 800hp into a 400hp

 

[obnoxious001]

Most of my boats are v-drives or outboards, but I raced a comp jet circle boat ( Advantage / Rogers ) it runs around 95 to 98 m.p.h with about 600 H.P.
.

I will state that you are fairly low with your 600 HP estimate if we are talking about Louis' engine in Moyle's boat, based on my hands on knowledge of that engine and previous dyno work before it got into our hands.

On the other hand, I know someone who had a 600 HP 468 in a Bahner that ran just over 100 mph,, so it does come down to how the boat is set up.

 

[Sleeper CP]

On the other hand, I know someone who had a 600 HP 468 in a Bahner that ran just over 100 mph,, so it does come down to how the boat is set up.

It would be great to build a 700 hp 6,400rpm pump gas 500" engine in a couple of boats and see what they could do.

Efficiency beats HP every time, it's cheaper too.

S CP

 

[Sleeper CP]

.

21 Eliminator -You have the best hull out there!
Hard to out engineer Chevy.

Go sell crazy somewhere else. :blah: :blah: :blah:


S CP

 

[rivermobster]

I looked into this a long time ago. I wanted to build a CP hull that would do 90+ easily on pump gas.

It all boiled down to needing about 700ci, to have enough touque to turn a A impelller in a blue printed jet.

How much would that cost??

Lets just say it would be cheaper to buy a nice Stoker.

 

[Sleeper CP]

I looked into this a long time ago. I wanted to build a CP hull that would do 90+ easily on pump gas.

It all boiled down to needing about 700ci, to have enough touque to turn a A impelller in a blue printed jet.

How much would that cost??

Lets just say it would be cheaper to buy a nice Stoker.

You were going to build a 700ci monster

Yikes, I think 700hp would get the job done. My open bow CP ran 86 with a 710HP 513" Ford with a AA AMT impeller spinning 5,400 or so.

S CP

 

[rivermobster]

You were going to build a 700ci monster

Yikes, I think 700hp would get the job done. My open bow CP ran 86 with a 710HP 513" Ford with a AA AMT impeller spinning 5,400 or so.

S CP

On regular fuel?? I'm think'n not.

I did say pump gas. I shoulda claified. I wanted it to run on good ol low octaine. No lope at idle, just a nice sleeper, to have some sunset fun in.

 

[obnoxious001]

It would be great to build a 700 hp 6,400rpm pump gas 500" engine in a couple of boats and see what they could do.

Efficiency beats HP every time, it's cheaper too.

S CP

A few years ago I built a 548 cu in pump gas (hydraulic flat tappet cam) engine that dynoed 700 HP,, went into a Southwind Tahiti. It peaked at 6100 and I know he was getting close to 100 mph with it last time I talked to him after bottom work, etc.

 

[white tortilla]

On regular fuel?? I'm think'n not.

I did say pump gas. I shoulda claified. I wanted it to run on good ol low octaine. No lope at idle, just a nice sleeper, to have some sunset fun in.

the boat in my avatar is a 19' cp, 572 that runs in the 104-105 range, all on 91 octane from chevron

 

[Outlaw]

well, I'm trying to get a hold on the cost, not the hp now. I've got a 300XS that is on my 21' Daytona. It goes 92mph with a 28p prop. Could easily pull a 30p, just to drop rpms a little for longevity. I've probably got close to 20k into the motor, hydraulic steering and install.

So, sounds like the cost would be almost the same to get a jet to go the same speed. Obviously, fuel efficiency is another topic. I guess the real test would be what kind of hp would it take to get my Daytona to go 92?

I'm thinking it wouldn't be able to get outta the water so easy with a motor inside. Probably need that 700-800 hp to get it to the same speed, maybe a little more.

I have less than $20K in my engine and pump. Including the EFI and blower
Have not dynoed it but should be north of 800 Hp @6300 on pump gas
It's a 8.4 to1 compression engine
At cruise it gets great fuel efficiency at WOT not so good
It takes a certain amount of fuel
To make 800+ ponies

Jets are not for everybody or for every situation

My last boat was a 21 open bow jet
Very heavy and would run 65 with
Around 550hp and I didn't have to worry about my young kids getting hurt on a prop

Sent from my iPhone

 

[460]

im 80 in my boat went 75 and some change with 450+/-( estiment) hp. Havent got a number since i added the silly gas. Its all about how you set it up and how efficent it is.

 

[Sleeper CP]

On regular fuel?? I'm think'n not.

I did say pump gas. I shoulda claified. I wanted it to run on good ol low octaine. No lope at idle, just a nice sleeper, to have some sunset fun in.

You typed 700ci not 700hp. Nearly any dip-stick can now build a pump gas 700hp engine ranging from a 512"-572" quite easily ( Ford or Chevy) and power a CP or Daytona and a few other boats to 90+ on pump gas no problem.

Now to do it on 87 octane and 700hp the range would be 9:1 compression and 540-572" engines, it would take some more thought process but it could be done.

S CP

 

[scottietwohoty]

My boat is pretty heavy and I have never touched the motor so as far as I know it's all STOCK from 1979 460 (330hp?) with I'm sure more hours than I care to know about. It runs about 56-57 mph on GPS with me and the wife, Bimini top up, 54 gal of fuel (87 oct), and I'm sure a pretty worn out pump. I would love to get it just even into the 70mph mark. Jet boat works GREAT for me.
I will run it till it won't run anymore then look into building a new motor (ford) and hopefully get where I want to be.

 

[Bense]

No. Jets only do 100 on eBay I/O

Guess you havent been boat races in about 45 years. Ask Tony how well the jet boats are doing in 7.0's lol

 

[toon]

Since it is my boat I will answer some of your questions. Motor is 800 hp @5800 rpm on pump gas made about 20 or so pulls on Westech dyno. Didn't cut any corners on build callies,dart,isky,je,arp etc... You can contact the motor builder for exact price but lower end of the range you listed is about right. And that price includes everything. I didn't have to supply a starter, alt, carb, headers, ignition or anything else. Boat is an open bow 22' stealth which weighs about 3000 lbs before anyone gets into it. When Greg Shoemaker lake tested the boat and ran 84 that was just a short run. He was impressed that it ran that well for such a big boat and said he could mess with the setup alittle more but why. Pump has a AA ss in it and has shoe, rideplate, inducer imp etc. I have had the boat up to 87.3 gps at 1350' of altitude and 80 gps at 5800' of altitude. Put this motor in a small light v or a tunnel hull and you are over 100 easy. Could most likely get a 21' tunnel over 100 easily. I had this boat built to be a family boat first, and a hot rod second. It runs like a dream. Doesn't load up, pulls skiers and the kids on tubes without bucking and barfing. I could tunnel ram and huge cam the motor and cut the impeller to get more top speed but thats not what I want. Let me know if you or anyone else has any questions about the boat, motor, or setup.
Tim

 

[460]

Guess you havent been boat races in about 45 years. Ask Tony how well the jet boats are doing in 7.0's lol

I wasnt going to go there.

But it would seem there are a few JETBOATS that have been eating vdrives for lunch as of late.

 

[BarryMac]

Since it is my boat I will answer some of your questions. Motor is 800 hp @5800 rpm on pump gas made about 20 or so pulls on Westech dyno. Didn't cut any corners on build callies,dart,isky,je,arp etc... You can contact the motor builder for exact price but lower end of the range you listed is about right. And that price includes everything. I didn't have to supply a starter, alt, carb, headers, ignition or anything else. Boat is an open bow 22' stealth which weighs about 3000 lbs before anyone gets into it. When Greg Shoemaker lake tested the boat and ran 84 that was just a short run. He was impressed that it ran that well for such a big boat and said he could mess with the setup alittle more but why. Pump has a AA ss in it and has shoe, rideplate, inducer imp etc. I have had the boat up to 87.3 gps at 1350' of altitude and 80 gps at 5800' of altitude. Put this motor in a small light v or a tunnel hull and you are over 100 easy. Could most likely get a 21' tunnel over 100 easily. I had this boat built to be a family boat first, and a hot rod second. It runs like a dream. Doesn't load up, pulls skiers and the kids on tubes without bucking and barfing. I could tunnel ram and huge cam the motor and cut the impeller to get more top speed but thats not what I want. Let me know if you or anyone else has any questions about the boat, motor, or setup.
Tim

Badass. Sounds like the perfect River boat... :thumbsup

 

[Fltplan]

Since it is my boat I will answer some of your questions. Motor is 800 hp @5800 rpm on pump gas made about 20 or so pulls on Westech dyno. Didn't cut any corners on build callies,dart,isky,je,arp etc... You can contact the motor builder for exact price but lower end of the range you listed is about right. And that price includes everything. I didn't have to supply a starter, alt, carb, headers, ignition or anything else. Boat is an open bow 22' stealth which weighs about 3000 lbs before anyone gets into it. When Greg Shoemaker lake tested the boat and ran 84 that was just a short run. He was impressed that it ran that well for such a big boat and said he could mess with the setup alittle more but why. Pump has a AA ss in it and has shoe, rideplate, inducer imp etc. I have had the boat up to 87.3 gps at 1350' of altitude and 80 gps at 5800' of altitude. Put this motor in a small light v or a tunnel hull and you are over 100 easy. Could most likely get a 21' tunnel over 100 easily. I had this boat built to be a family boat first, and a hot rod second. It runs like a dream. Doesn't load up, pulls skiers and the kids on tubes without bucking and barfing. I could tunnel ram and huge cam the motor and cut the impeller to get more top speed but thats not what I want. Let me know if you or anyone else has any questions about the boat, motor, or setup.
Tim

Yes, your boat was the basis of the thread I was reading. So, if you have 20k into the engine and pump setup, our boats stand pretty equal speed wise, which is what I was trying to figure out. Lack of storage and fuel efficiency are a couple things that I would lose if I were to put a jet into mine. That would require a different/bigger hull to get the same usefulness.

Now, about that ILMORE IO for my hull with about 700hp, that would be a fun ride too!

 

[Sleeper CP]

Since it is my boat I will answer some of your questions. Motor is 800 hp @5800 rpm on pump gas made

Boat is an open bow 22' stealth which weighs about 3000 lbs before anyone gets into it.
Tim

That's the second choice to a TPR 21' deck boat.

Nice boat, I have only ridden in a steath with an I/O and 6ltr engine. Nice running boat. I don't think I ever rode in a jet.

S CP

 

[woodagain]

That's the second choice to a TPR 21' deck boat.

Nice boat, I have only ridden in a steath with an I/O and 6ltr engine. Nice running boat. I don't think I ever rode in a jet.

How bout an open bow 22 with outdrive. I think it curled your hair!!

Go sell crazy somewhere else.


S CP

How bout an open bow 22 with outdrive.
I think it curled your hair!!

Go sell crazy somewhere else.

Is that FORD back at Gregs again ?
WHAT NOW !?

 

[rivermobster]

You typed 700ci not 700hp. Nearly any dip-stick can now build a pump gas 700hp engine ranging from a 512"-572" quite easily ( Ford or Chevy) and power a CP or Daytona and a few other boats to 90+ on pump gas no problem.

Now to do it on 87 octane and 700hp the range would be 9:1 compression and 540-572" engines, it would take some more thought process but it could be done.

S CP

I meant to type 700ci

The ONLY jet boat i would consider owning would be the exact same hull you have (without the open bow though).

 

[Outlaw]

How bout an open bow 22 with outdrive.
I think it curled your hair!!

Go sell crazy somewhere else.

Is that FORD back at Gregs again ?
WHAT NOW !?

I want a ride


Sent from my iPhone

 

[RACER J]

The rough cost to run over 100mph in a jet boat. Keep in mind no labor is included.
New Place Craft bare hull 10,000
Old engine out of race car 496ci 8,500ish (700-750hp)
Lo pro intake and pump 4,500
Jet Away 1,300
Pop-Off 1,800
Plus a bunch of other shit!!!! Gets you 110mph

 

[TRG]

My 500# 19' TPR stealth Family four seater Jetboat is equipped with a 540 CI Chevrolet, engine made power at 6600 rpm and made 800 hp on the nose with 91 octane pump gas dyno'd @ Westech performance group, in the boat I I would not say that the spin 64-6600.
I recently tried out the NJBA and found that it ran 10.46 @ 101mph, mind you this was with the shoe buried to the intake and hardly any inlet pressure, I would not say that the boat is too efficient! (Not yet anyway)
I will be doing some testing here in the next couple weeks and find out if there is any more left.
At the track, my boat was GLUED to the water, so......ya, it was pretty safe!

 

[DaveC]

I had a 21 daytona jet and needed 750 Hp 540 to go high 80's. Thats with a ton of bottom and jet work. I converted it from an OB. Heavy boat

I sold it after 1 year because using race gas in a jet is insane. Lol

I could build just that motor for $11k without rigging. Rigging for a jet is a couple grand plus the jet

If I were to do it over again I wouldn't do it. There is a guy running around in a 21 daytona with an IO and that thing runs hard (120++)

You would need so much less power with the IO to go fast. Plus the lighter hull would be easy on the OD. All around the IO would be better. It would cost more but its only $$