Props Vs. Jets...

[Crime Pays]

What is everyone's preferred choice for propulsion? Pro's, Con's. Power, Economy, Safety? My Question is Power. What kind of speeds can I expect out of a 502/dominator powered 21' Essex Genesis? :confused:

[Kilrtoy]

First and foremost
WHERE DO YOU WANTTO BOAT.
That will answer your question

[Havasu_Dreamin]

Propulsion all depends on what you want to do with he boat and where you plan on boating, as Kilr stated.
The holeshot on a jet will be better than the a sterndrive propelled boat. We had a 21 foot Essex Sterling with the 350 MAG and the Bravo III drive and we saw anywhere from 58-65. Given that, the less weight of the Genesis and the increase in HP of the 502 over the 350, I suspect you'll see somewheere between 60 and 65.

[Crime Pays]

Needles,Havasu, Nacimiento

[Kilrtoy]

You need a prop,
A jet would work great for lower water or rivers,
what you mentioned you would be better suited with a prop

[dgie]

Jets shoot water higher :D

[dmontzsta]

V-Drives...there is nothing else.

[ahhell]

needles=jet
havasu=prop
frequent fillups=jet
chance of bleeding profusely=prop (had to)
squirting peeps=jet
:rollside: :rollside: :rollside:

[Mohavekid]

Acceleration is better on the jet.
Jet is safer too.
Low water use is the jets forte'.
Gas mileage should be similar given the same size motor driven at the same RPM's. Maintenance should be less on the jet and is something that can be done by anyone.
The prop has the edge in top speed.
The jet is generally more "fun" to drive despite the slower speed.
I would estimate top speed in the jet as described to be about 55 MPH. The same boat and motor with an prop and I would guess at least 65 MPH.

[ahhell]

Mine has a 454/Domintor set up...full crew(6-8) and fuel , 45+, just me and less fuel almost 55 non-gps

[WUTWZAT]

A jet boat is great fun and a lot less worry when your in shallower waters, but you still got to be concerned with sucking up rocks and sand and in some places seaweed or grass. A jet in a similiary equiped boat may have a great hole shot (may) but in the end will tend to be slower in the top end. There are some exceptions, and these guys jets seem to run with the v-drives in hole shots and top end but I would guess they have a lot of time and money invested in finding their winning combination. Examples of fast jets in my opinion are and not limited to FourQ, Nucking Futs, LakesOnly, Cyclone, Rivertard and a few more who slip my mind right now. But these guys boats stand out as real performance machines that seem like typical jet boats but seem to have that little extra something that makes everyone sit up and take notice.
Now when it come to an I/O type boat they seem to run real well but seem to be associated with more of a family or runabout type, which I've never understood cause the seem to be real effective at turning horsepower into speed.
And then V-drives always seem to be quick, but its one of those things where you have an exposed prop that can be damaged in shallow water or by odd things like stumps or rocks / sandbars.
I built my first boat, a jet with a real mild motor hoping to get something easy on the fuel economy and that would handle fairly well and let me learn how all the systems are to work.
If I was to build another boat, which I am considering. I got two directions I am thinking of going. One is a high HP v-drive, but I think I would be less likely to take this one out just for concerns that I always go shallow places and I have seen what a rock can do to a prop.
The other is really more an experiment. A jet drive with a supercharged or turbocharged import motor. I used to run a class 1 off-road car with an Acura V-6 that did real well. I feel it had more than enough power, but with the constant flow of cool lake water a turbo motor would run great. It would be more of a fit concern in building all motor mounts and connection, basically drive line would be a concern. Not really searching but if I ever happened across a hull I might consider starting that project. I know a bunch of jet boat old schoolers would be against it but, I would have fun because I know the motor whine itself would cause others to look.
Jason

[Dave C]

I totally disagree with some of the statements made here.
Props, especially I/O's, are MUCH MORE efficient. Great for cruising at WOT and mid range. I/O's are great for rougher water too. Good all around, especially top and mid range MPH. (except starting line accelaration)
Jets are less efficient but just plain fun nonetheless due to their acceleration, but they do suck down the gas. they don't work too good in rough water. they have much less efficiency in the mid range and top end.
I have owned 5 boats (3 jets, 2 I/O's various size motors, 2 flat bottom 3 cats) and the I/O's are great for cruising around for a long time at high rates of speed in smooth and rough water.
Also on the I/o as the efficiency and speed of the prop increases it results in lower RPM and a greater MPH for the I/O . Example, my 21 Jet ran 80+ mph @ 5500 rpm, my much HEAVIER 22 MTR I/O ran 80 mph @ 4,000 rpm (BIG DIFFERENCE) Plus the I/O cruised at 65 MPH at 3,500 rpm. Plus the I/O had less HP. (I/O had 470 HP and the Jet had 800 HP)
Like they say... depends on what you want to do, but also how much $$ you got to burn.

[1978 Rogers]

Jets shoot water higher :D
I'll second that motion. Everyone here say "I". "I". :smile:

[Debbolas]

needles=jet
havasu=prop
frequent fillups=jet
chance of bleeding profusely=prop (had to)
squirting peeps=jet
:rollside: :rollside: :rollside:
OMG!!!
I can't believe you brought this up!!
bleeding=prop
LOL :rollside:

[CrazyHippy]

I've been boating for 20+ years now (im only 25) almost all of it behind prop boats (I/O's for the 1st 12-13 yrs, a few v-drives, and outboards :cool: recently) and have NEVER hurt myself on the prop... I also do not drink while i am on the water.
Perhaps you should say Jets are safer if you are accidentally challenged (dont try skydiving BTW), or are a drunk, that tends to do stupid things.
My experiance (comparing w/ friends boats) is that Jets are harder on motors because you are cruising at a much higher RPM (4300 vs. 3200)
Jets do have teh advantage in really shallow water, but once again, there are VERY few times that i've hit a prop or skeg. You just have to be smater than the bottom of the river..LOL
BJH

[dmontzsta]

I am reading this and some of you rattle what YOU feel off the top of your head, but dont really know facts. :skull:

[HammerDown]

Here's efficient > > > Last week I was in a friends 33' Skater.
At 2,800-3,000 rpm we were at + 60 MPH.
At 4000 rpm we busted 80 mph
At 4800 rpm we were in the 90's
It tops out at +130 mph at with a red line of 5550 rpm.
(now thats just sick) :notam:

[Rocket2003]

Power / Efficiency ratio! Hands down a Prop is better! :D Now if you need to shoot a big rooster Tail, Get ya a Jet! :rollside:
My $.02 :coffeycup

[Havasu Hangin']

Here's efficient > > > Last week I was in a friends 33' Skater.
Skater makes a 33'?
The bottom line...if you buy a jet, you are owning the same technology that drives a PWC (or a sprinkler). :notam:
A prop uses the same priniciples that drive an airplane.
Which is cooler...a sprinkler or an airplane? :cool:

[bchbum]

I love my Ultra jet , when I'm towing the kids on the tube I use at least 15 gallons of fuel an hour . With a stock 454 (330) hp I get into the low 50's , but it's a great run at that speed . Our next boat will be a prop & a couple of feet bigger .

[Jeanyus]

Jet=forward and reverse with 1 moving part.
I can and have used my sprinkler to put out a prop boat that was on fire.
High performance boaters are going to tell you they get good fuel economy :rolleyes: :rolleyes:

[dmontzsta]

Jets get the worst fuel economy. You have seen or heard how many rpm it takes for a jet to plane out and cruise?

[Havasu Hangin']

Ever try to back up a jet?
Jet=forward and reverse with 1 moving part.
Yeah...that "one moving part" is about as effiecient as putting your finger over a garden hose.
So if less parts are better, then maybe we should all be riding in horse and buggies ('cuz cars have so many more of those damn "moving parts")? :rolleyes:

[Mohavekid]

Fuel use is relative.
A motor running 3500 RPM will burn the same amount of fuel regardless of the type of drive it is turning.
The difference in mileage from the jet to a prop comes from the efficiency or lack thereof in the propulsion system.

[Havasu Hangin']

A motor running 3500 RPM will burn the same amount of fuel regardless of the type of drive it is turning.
Uh...doesn't load on the engine determine mileage?

[dmontzsta]

Another thing I would like to comment on is "hole shot". I used to think jets had a better one cause of all I read on the boards. But when I had some experience I dont believe it is true, V-Drives can change gears and props for less than it costs to rework a pump. Here is an example, I have 17 gears 12x15 prop, which any prop guy knows is alot of gear and alot of prop for nearly stock 390 Ford. We lined up next to a guy with a worked up pump AB impeller? built and stroked 455 running av-gas, the whole shot was dead nuts until he pulled away at about 25-30mph just because he had around 200+hp more.

[Mohavekid]

Uh...doesn't load on the engine determine mileage?
Yes.
A boat motor at a steady cruise is always under load, so there is no difference in fuel consuption between the same size motors run at the same RPM assuming they are properly tuned.
The mileage difference comes from the different speeds attained by the prop boat and the jet boat at that RPM.

[Mohavekid]

Another thing I would like to comment on is "hole shot". I used to think jets had a better one cause of all I read on the boards. But when I had some experience I dont believe it is true, V-Drives can change gears and props for less than it costs to rework a pump. Here is an example, I have 17 gears 12x15 prop, which any prop guy knows is alot of gear and alot of prop for nearly stock 390 Ford. We lined up next to a guy with a worked up pump AB impeller? built and stroked 455 running av-gas, the whole shot was dead nuts until he pulled away at about 25-30mph just because he had around 200+hp more.
Hole shot is generally better on a jet than most I/O's because the jet can spin the impeller at full RPM regardless of the boat speed, thus taking advantage of all of the available horsepower immediatly. The I/O can not rev to max RPM until the speed of the boat increases to maximum unless the prop experiences cavitation.

[Dave C]

you need to add to this statement ... "all other things being equal"
which of course, they never are! ;) (not true with higher VE or forced induction) Otherwise I would agree.
A motor running 3500 RPM will burn the same amount of fuel regardless of the type of drive it is turning.
but our point is that the gear reduction in the prop boats always net a lower RPM for the same MPH. Therefore it nets a higher MPH for the same RPM. :D

[Havasu Hangin']

A boat motor at a steady cruise is always under load, so there is no difference in fuel consuption between the same size motors run at the same RPM assuming they are properly tuned.
But if a jet pump is less efficient at proividing thrust to the hull, then the engine will have more load at steady cruise, right? RPMs are just one factor.
For example...lets take two equal trucks.
Truck #1- you sit in your driveway and rev the engine to 2,500 rpms.
Truck #2- You pull a 12,000 lb load up a hill at 2,500 rpms.
Same size motors, same tuneups, same rpms. Which burns more GPH?
RPMs are not apples to apples. Load determines fuel efficiency.

[Dr. Eagle]

Hole shot is generally better on a jet than most I/O's because the jet can spin the impeller at full RPM regardless of the boat speed, thus taking advantage of all of the available horsepower immediatly. The I/O can not rev to max RPM until the speed of the boat increases to maximum unless the prop experiences cavitation.
Perhaps true, but I have a friend with an 18' jet with a 454 of about 550 HP or so and my 21' Ultra with a 350 Merc Magnum can out hole shot and top end him...
It is true that the engine RPMs come up quicker on a jet, but with a comparable amount of HP/engine size between a jet and an IO, IMHO the IO will always prevail. :D

[ahhell]

as a jet owner id have to say depends on who your hole shoot (that sounds dirty) ill i know is that at 5k rpm im touching the back side of 49 mph and watching my fuel gauge tick like a second hand (26 gallons per gauge)
lucky fore my the mrs. like to see the sights while were boating...dont worry ill be along shortly :cool:

[Mohavekid]

But if a jet pump is less efficient at proividing thrust to the hull, then the engine will have more load at steady cruise, right? RPMs are just one factor.
For example...lets take two equal trucks.
Truck #1- you sit in your driveway and rev the engine to 2,500 rpms.
Truck #2- You pull a 12,000 lb load up a hill at 2,500 rpms.
Same size motors, same tuneups, same rpms. Which burns more GPH?
RPMs are not apples to apples. Load determines fuel efficiency.
I said 2 motors under the same load at the same RPM and all other variables being constant, would burn the same amount of fuel.
A boat motor at a steady cruise speed is always under load, be it from a prop or a jet.
Is the load the same between the jet and the prop at the same RPM? I don't know.

[ahhell]

is it possible to make a duel jet system??? say a "transfer case" with two pumps mounted side by side...my idea, i claim it :boxed:

[Scream]

is it possible to make a duel jet system??? say a "transfer case" with two pumps mounted side by side...my idea, i claim it :boxed:
Sounds like one of your ideas alright...lol

[Havasu Hangin']

Is the load the same between the jet and the prop at the same RPM?
No.
If you're talking about two identical boats, hull drag will be pretty equal (I won't get into the fact that a jet by nature needs more wetted surface)...
...but it's how efficient the forward thrust is made. Since jets are less efficient, in general, they take more HP to produce the same forward thrust as a prop.

[victorfb]

If fuel economy is your biggest concern about boating, id suggest a differant hobby.

[Havasu Hangin']

If fuel economy is your biggest concern about boating, id suggest a differant hobby.
No kidding.
http://www.***boat.com/image_center/data/520/74the_cig_engines.jpg

[dmontzsta]

Hole shot is generally better on a jet than most I/O's because the jet can spin the impeller at full RPM regardless of the boat speed, thus taking advantage of all of the available horsepower immediatly. The I/O can not rev to max RPM until the speed of the boat increases to maximum unless the prop experiences cavitation.
I was talking about V-Drives. The best of all.

[Kilrtoy]

HH,
So what is the top speed you have reached so far, I remember you said 75 but havent gotten on it yet.....

[77charger]

I have to agree with HH on the gas consumption at 3500 rpm.(I cant believe i said that :messedup: )
Also i think a jet is way better suited for an under 19ft boat.When i go to needles or anywhere where there is current in the water i see 21ft jets trying to get on plane going upriver they just rev and go no where when loaded.I own a 21ft with a 350 mag with a prop it has no problem getting on plane loaded wheter up or down river.It also ges on plane faster than the jets of equal size ask rivercrazy he had a similar hull as mine but with a 390hp jet and also rode in mine.as for speed i can see 60 on a good day and 57 under normal summer heat.
But a jet on an 18ft boat seems to work very well all around if pump work is done they will get good efficiency.Just better suited for lighter set ups.

[Wicky]

Power / Efficiency ratio! Hands down a Prop is better! :D Now if you need to shoot a big rooster Tail, Get ya a Jet! :rollside:
My $.02 :coffeycup
I was in Mission Bay yesterday. If you really really want a big rooster tail, buy a turbined hydroplane!!!

[CrazyHippy]

I was in Mission Bay yesterday. If you really really want a big rooster tail, buy a turbined hydroplane!!!
Know of any dealers in the vegas area?? I hear chicks dig the rooster tail, and now i'm interested...LOL
BJH :boxed:

[Havasu Hangin']

HH,
So what is the top speed you have reached so far, I remember you said 75 but havent gotten on it yet.....
Yeah...that's about it for now. It was still climbing, but the props were slipping bad (20%). I need some chop to loosen it up.
I'm gonna try to switch the outdrives. Somebody said that with 4 blade props, spinning them out (how they are now) creates more transom lift, so it has a tougher time carrying the nose.
We'll see. I think with 5 blades and boxes I should have 85 MPH...but that's a winter project.

[WUTWZAT]

Ok, a lot of you made really good points on everything, and when comparing things you can never apples to apples any of these boats because of so many veriables. here is my quick summary.
Jets, suck fuel, run shallow, = fun, require slightly more hp for the same bang. Good for little boats more weight / length require more HP.
(Advantage runs shallow water with less concern)
V-drives, suck fuel, run normal water, = fun, more hp = more speed.
(Advantage runs faster than jet in apples to apples motor/hull set up in most, disadvantage, prop hangs lower in water, gotta watch out for that odd rock sticking up that'll bend your prop)
I/O, sucks fuel, runs same water as V-drive with same concerns, better suited to turning smaller hp motor set up into speed with bigger heavier boats which = more effienciency. (Advantage for a bigger family style boat cause it handles the weight and length better, might not have the acceleration of a jet / v-drive (hp - hp) but still fun. But still can get to speed or even surpass a jet in speed once past hole shot, which c'mon is a matter of seconds right.
I know my little jet, takes off quick, can get to plane in a relativley short time but then tops out around 60mph. More top end would be nice but that a matter of more rpm, but I am running a small block chevy in b impellor jet boat, very rare, and its under carburated. For fun factor I need a jet-o-vator, for possible speed maybe a larger carb. I'd rather have the fun for the money spent. I feel my set up is real mild and effiecient so far, but then again everything is brand new from fresh rebuilds. We will see how things hold up in the long run.
If I wanna go fast, I can always catch a ride in a V-drive, Dmontzsta or a slow ride with Beautiful Noise (yeah right) Everything is fun on the water and it is now as it has always been, Speed cost, how fast would you like to spend it.
If I had a family, my money would be on a 21' + I/O factory V-8 for the reliablilty. Throw a swim step on that bad boy if you have concerns about getting cut on the prop, and don't hang out in the rear with it running.
Jason

[Dave C]

No sh*t!....... you hit the nail on the head.
we should be worried about BPH (beers per hour!) :D
If fuel economy is your biggest concern about boating, id suggest a differant hobby.

[Dave C]

although I have seen some 21 Daytona I/O's in Norcal that can out hole-shot and out-MPH anything.
Also it doesn't take as much HP as you think to out hole-shot a jet. Just a good repair shop!!!! :hammerhea :)

[dmontzsta]

If I wanna go fast, I can always catch a ride in a V-drive, Dmontzsta or a slow ride with Beautiful Noise (yeah right) Everything is fun on the water and it is now as it has always been, Speed cost, how fast would you like to spend it.
You mean a fast ride in Steves boat and a slow ride in mine right Jason? :D

[BarryMac]

Jets are cheaper to maintain (Less moving parts). They are not fuel efficient at all, but what boat is really fuel efficient??? My 21'er has the juiced 454, 380hp, top speed is about 60mph and it is a whole hell of a lot of fun to drive. Plus it loves shallow water and you can't boat shallow water in a boat with an I/O, I know becasue I've been there to...
gjb

[WUTWZAT]

Don, you know Steve is the "King" of the slow folks.
Did you get that prop all squared away yet, which ones did you like and plan on using?
And FC2, your gonna be there, right?
Jason

[dmontzsta]

Don, you know Steve is the "King" of the slow folks.
Did you get that prop all squared away yet, which ones did you like and plan on using?
And FC2, your gonna be there, right?
Jason
Steve can beat me, so he cant be too slow. :D
Got the prop fixed for $75 almost immediately after and it is soooo much better than before.
FC2 is a negative. I blew the motor at Elsinore squeezing the bottle too hard on the old motor, new motor is going in and I hope to be at Elsinore next weekend...we shall see...my newest project is a 429ci I am getting ready to start building.

[WUTWZAT]

WTF, happened to the I just need a 390.....
Dons doing a little grap for the HP, huh..... is this one going to be bottle feed, of course it is.....
What let go in the motor, where was the problem. Rods, bearing or was it just a catistrophic failure.
Like we used to say in racing, it was an electrical problem. Oh how so? Well, when the piston shot throw the block it knocked the distributor off and we lost all spark to the rest of the motor.
Jason.
I should have the blue beast back tomorrow.

[Kim Hanson]

I am reading this and some of you rattle what YOU feel off the top of your head, but dont really know facts. :skull:
I talk from driving them, Ob Tunnel is fast, smooth, driving and safe. V-drive is crazy shit for beating you up and going straight, okay they pull tubes really good and sink the same way :D
I don't like I/O's, looks like something is missing..example though...same Lake me with my whacker and an I/O, went out for the day and as we took them to the launch...Mine was all shiney, his was all crumpled..$ 700.00 bucks down the drain, he didn't feel anything and this guy has been boating for ever, lives at Loon Lake!
I rode in a Jet that was fast, Rob from Eagle Racing..fast focking boat, when you wear helmets, lifeline jacket and a 5 point harness = fast chit!
Thats all I know........( . )( . ).......I would love a 21" Liberator with a 300 X..thats tits! Got to ride in Havasu Barneys & Havasu Secrets..sweetttttt boatsss! My humble opinion! ;)

[396_WAYS_TO_SPIT]

This is why i dont own a prop LMFAO! :D :D
http://www.***boat.com/image_center/data/521/239outdrive.JPG
http://www.***boat.com/image_center/data/521/239outdrive2.JPG
http://www.***boat.com/image_center/data/521/239outdrive3.JPG

[460 jus getn it]

thats a nice 2x4

[Kim Hanson]

Another thing I would like to comment on is "hole shot". I used to think jets had a better one cause of all I read on the boards. But when I had some experience I dont believe it is true, V-Drives can change gears and props for less than it costs to rework a pump. Here is an example, I have 17 gears 12x15 prop, which any prop guy knows is alot of gear and alot of prop for nearly stock 390 Ford. We lined up next to a guy with a worked up pump AB impeller? built and stroked 455 running av-gas, the whole shot was dead nuts until he pulled away at about 25-30mph just because he had around 200+hp more.
I don't think he is looking at holeshots Tweety, looking at different types and which are best. Or did he say he was going to race it? :confused: ........( . )( . ).........If you have enough power in it, you will catch them....no matter what! :sleeping:

[Kim Hanson]

This is why i dont own a prop LMFAO! :D :D
http://www.***boat.com/image_center/data/521/239outdrive.JPG
http://www.***boat.com/image_center/data/521/239outdrive2.JPG
http://www.***boat.com/image_center/data/521/239outdrive3.JPG
I think thats the Park Brake, new option......( . )( . ).......Did you skeeg it! :p

[Kim Hanson]

I was talking about V-Drives. The best of all.
Please stop talking or typing.........( . )( . )......... :yuk:

[Kim Hanson]

Ok, a lot of you made really good points on everything, and when comparing things you can never apples to apples any of these boats because of so many veriables. here is my quick summary.
Jets, suck fuel, run shallow, = fun, require slightly more hp for the same bang. Good for little boats more weight / length require more HP.
(Advantage runs shallow water with less concern)
V-drives, suck fuel, run normal water, = fun, more hp = more speed.
(Advantage runs faster than jet in apples to apples motor/hull set up in most, disadvantage, prop hangs lower in water, gotta watch out for that odd rock sticking up that'll bend your prop)
I/O, sucks fuel, runs same water as V-drive with same concerns, better suited to turning smaller hp motor set up into speed with bigger heavier boats which = more effienciency. (Advantage for a bigger family style boat cause it handles the weight and length better, might not have the acceleration of a jet / v-drive (hp - hp) but still fun. But still can get to speed or even surpass a jet in speed once past hole shot, which c'mon is a matter of seconds right.
I know my little jet, takes off quick, can get to plane in a relativley short time but then tops out around 60mph. More top end would be nice but that a matter of more rpm, but I am running a small block chevy in b impellor jet boat, very rare, and its under carburated. For fun factor I need a jet-o-vator, for possible speed maybe a larger carb. I'd rather have the fun for the money spent. I feel my set up is real mild and effiecient so far, but then again everything is brand new from fresh rebuilds. We will see how things hold up in the long run.
If I wanna go fast, I can always catch a ride in a V-drive, Dmontzsta or a slow ride with Beautiful Noise (yeah right) Everything is fun on the water and it is now as it has always been, Speed cost, how fast would you like to spend it.
If I had a family, my money would be on a 21' + I/O factory V-8 for the reliablilty. Throw a swim step on that bad boy if you have concerns about getting cut on the prop, and don't hang out in the rear with it running.
Jason
You forgot " OB's"........( . )( . )........ :hammer2: :D

[dmontzsta]

Please stop talking or typing.........( . )( . )......... :yuk:
You fag hanson, stop replying to everything I say, you are like a stalker.
:hammerhea

[dmontzsta]

I talk from driving them, Ob Tunnel is fast, smooth, driving and safe. V-drive is crazy shit for beating you up and going straight, okay they pull tubes really good and sink the same way :D
I don't like I/O's, looks like something is missing..example though...same Lake me with my whacker and an I/O, went out for the day and as we took them to the launch...Mine was all shiney, his was all crumpled..$ 700.00 bucks down the drain, he didn't feel anything and this guy has been boating for ever, lives at Loon Lake!
I rode in a Jet that was fast, Rob from Eagle Racing..fast focking boat, when you wear helmets, lifeline jacket and a 5 point harness = fast chit!
Thats all I know........( . )( . ).......I would love a 21" Liberator with a 300 X..thats tits! Got to ride in Havasu Barneys & Havasu Secrets..sweetttttt boatsss! My humble opinion! ;)
How about turning?
BTW: There are LOTS of V-Drivers wearing helmets and 5 point harnesses too. I think Jim (UCLAHATER) said it best "At the end of the day, the fastest boat is the fastest v-drive". Come to SoCal, there are guys here that would make your whacker their bitch. :argue:

[canuck1]

Jets get the worst fuel economy. You have seen or heard how many rpm it takes for a jet to plane out and cruise?
Yep I have to push it all the way to 3000 to jump on plane, and cruising around at 2500 is just pushing it too hard
And if you think you can out turn a sprint boat.....

[dmontzsta]

Yep I have to push it all the way to 3000 to jump on plane, and cruising around at 2500 is just pushing it too hard
And if you think you can out turn a sprint boat.....
We are talking lake boats here and we know that your standard jets dont turn that well.
If you want to talk competition boats look at all the Ks.

[canuck1]

Mine is a lake boat/standard jet and it turns real well
As for comp boats a K boat will not out turn a sprint

[rivercrazy]

I had jet boats for many years. Still like them. However, from an efficiency standpoint, an I/O comes out on top.
Say your cruising at 3,500 rpm in a 21' jet with a big block 454. That might get you 30-35mph with a taller impeller. In my former boat, I'd get about 2mph at best with this setup.
Say your cruising at 3,500 with an I/O with a 496. At least in my 25'er I'm crusing in the high 40's. I've clocked my I/O at almost 4mpg at that rpm. Plus your traveling at a higher rate of speed at the same rpm. The increase in speed alone significantly adds to MPG.
Plus the ability to carry the nose with the prop boat will make for a much more comfortable rough water conditions. A jet will plow into wave that you fly over with a prop.....
Plus my 2,600lb 21' jet boat with a 390HP 454 would do at best 57-58mph and cruise about 42-43mph @ 4K rpm.
My 25' 4,300lb deep V 496 driven boat (425hp) tops out at 72mph and cruises 55mph at 4K rpm.

[canuck1]

I had jet boats for many years. Still like them. However, from an efficiency standpoint, an I/O comes out on top.
Say your cruising at 3,500 rpm in a 21' jet with a big block 454. That might get you 30-35mph with a taller impeller. In my former boat, I'd get about 2mph at best with this setup.
At 3500 I'm in the mid/high fortys with a 'B'ish imp
Say your cruising at 3,500 with an I/O with a 496. At least in my 25'er I'm crusing in the high 40's. I've clocked my I/O at almost 4mpg at that rpm. Plus your traveling at a higher rate of speed at the same rpm. The increase in speed alone significantly adds to MPG.
I do the same with a mild 350
Plus the ability to carry the nose with the prop boat will make for a much more comfortable rough water conditions. A jet will plow into wave that you fly over with a prop.....
Wedge/diverter? and a 20' bottom don't ride that bad and waves are made for jumpin
Plus my 2,600lb 21' jet boat with a 390HP 454 would do at best 57-58mph and cruise about 42-43mph @ 4K rpm.
at 4k cruise I'm over 60
My 25' 4,300lb deep V 496 driven boat (425hp) tops out at 72mph and cruises 55mph at 4K rpm.
My 16' 1400lb deep V 350 driven boat (355 hp) tops out at 78 and cruises at 45+ at 3500 rpm and never saw a gravel bar that it was scared of :wink:

[rivercrazy]

But your comparing a 16' boat made out of recycled beer cans to a 4,300 pound boat made of glass....J/K about the recycled beer can comment!

[canuck1]

But your comparing a 16' boat made out of recycled beer cans to a 4,300 pound boat made of glass....J/K about the recycled beer can comment!
It is a recycled beer can and Jungle Boys numbers are about the same in his 19'.
I think the hull/drive tech in the newer boats makes the biggest difference, now if you compair a 70's i/o with a 70's jet?