Do we really need a 6l to get 409hp?

[Jefverstrom]

When F1 reduced their engine size from V8 to V6 this year to reduce fuel consumption of the cars I was thinking why the boat companies don't do the same to our boats?

 

I think i speak for most of us here when I say we want those 409 (450 sometimes) horses for both slalom and jump but isn't there a better way to get the same amount of power from a smaller engine, like a turbocharged V6 or likewise.

 

Are they doing any testing with this? anyone know why it would work or why it wouldn't?

[Boat030]

A smaller displacement motor wouldn't necessarily give you better fuel consumption if you were trying to get the same HP. The new F1 V6 is a turbo motor, I'm not sure if the speed control on a ski boat could handle keeping the boat from pulling the rope out of your hand when the turbo kicked in?

[skierjp]

Turbos, one more thing to break or go wrong, just ask anyone who has owned a Ford diesel truck or the ecoboost engine.

[GOODESkier]

Doesn't the 409 hp get better fuel economy than the 343 hp? I mean if you are just skiing at 34 or 36 all the time? I have little experience with the 409, but that is the rumor I have heard.........

 

Still waiting for toyota to give me the marine engine of my dreams in a new Nautique 200..........

[Skoot1123]

I believe it is a combination of HP and Torque that the challenge comes in. Torque for getting the skier up and out of the water and HP for that speed for jumping. If I am not mistaken this is one of the main reasons that MasterCraft went to ILMOR engines. Someone please correct me if I am wrong or misinformed.

[skier2788]

I dont think a turbo or super would work well in a boat. The speed control we have is trying to adjust the speed every second? Turbo and super have too much lag time for what we want. As a drag racing friend always says "there is no replacement for displacement."

[Jody_Seal]

@Jefverstrom, $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$Do you realize how much a Marine Small cubic inch supercharged/turbo engine will cost? Right now the Blown 550 package is a $12,000.00 up charge on wake board boats.

Don't these boats cost enough as it is?

We should start seeing in the future some 5.3 L LS engines and maybe some v-6 platforms that will pack a compact reasonable bit of HP.

[ral]

For slalom, for sure we do not need 409 HP either.

 

I like 5.7-340HP engines far more. More buoys and less sore back...

[oldjeep]

A 15,000 rpm F1 engine in a boat - that would be pleasant to listen to.

[E_T]

The problem is R&D theses are SBC motors. Ask @Horton the price if a F1 motor... I can tell you a nascar cup car motor that puts out 900 HP and is a 6L? Cost up to 100k. Turbos are wacky and create to much heat. I could put a blower on a 5.3L and it would get the job done and cost around 5k. I would go on but I'm on a cellar device. I'll rack your brain at a later date

[Boat030]

A supercharger or pro charger would probably work ok, but not sure what the advantage would be over bigger displacement except maybe you could save some weight. After I typed my first response I got to thinking more about a turbo, the R&D would be ridiculous but if you could tie in waste gate management to the speed control you might be able to come up with a pretty small motor that could produce the torque & hp you need.

[boarditup]

The Porsche flat 6, without boost, can and will produce over 400 hp. To do this it spins fast, requires premium fuel, and has a lot of computing power. The torque curve is at much higher rpms that what we are used to for a ski boat. Premium fuel is an issue in a boat. Most manufacturers plan on 85 octane fuel for the boat motor. So a motor with a very high state of tune and high compression may not run well in the real world of boating.

 

That said, when they get a CVT that will hold 350 ft lbs of torque and can be coupled to the speed control, then we have the potential of a smaller motor making it all work. Imagine a flat 4 or flat 6 completely under the floorboards of a slalom boat....

[Texas6]

Love V8 horsepower but still feel today's smaller diesels could do this job reliably and effortlessly - with plenty of torque and good gas mileage - someone please refresh my memory on why this won't work?

[E_T]

@Texas6‌ to get the power from a diesel you need a turbo....they have lag and would be wacky with zero off. You need room for all the plumbing. And with high EGT's I don't see it being a good thing.

[Horton]

@DW‌ ?

[oldjeep]

A hemi 5.7 puts out just under 400HP in pickup trim. Doesn't seem like a big block is needed, just a better small block ;)

[Waternut]

No we don't need 6L power but we do need reliability and low cost. F1 engines are mind blowing expensive and don't last very long either. Miilions of dollars in the budget and two world champions made it 5-6 laps without engine failure in the first race of the season. There are plenty of people on here with over 1000 hours on their boat engines. Good luck getting a cheap, high powered engine to last that long with considerably less displacement. The other issue is smaller displacement engines inherently have less torque at lower rpms and usually produce optimum power at a smaller range in the spectrum. Could be a big problem keeping the boat on plane at trick speed while still providing optimum power at slalom speeds.

 

Unless someone can figure out how to incorporate gear changes into a watercraft, we're kinda stuck with big displacement engines.

[Boat030]

Gear changes would be relatively easy, we use Owens or Lenco type transmissions in the race boats without any issue. The real issue is as you stated the cost, the v8 small block is easy and pretty inexpensive so no real point in going through all the energy and expense to come up with something new. Fun to think about though.

[MattP]

@SkiJay‌ you race cars too right? Any input?

[Texas6]

My primary driver is a turbo diesel p/u. I agree @ET that without turbo there can be some lag, but it isn't like it used to be in the early days. I can watch the turbo gauge on my pickup to see how much boost is being used when I accelerate. When its at speed, it uses very little if any turbo to accelerate, and still lots of torque (i.e. holding a PP speed). I'm sure @DW can set me straight if I'm off base and I very well could be.

[Craig]

The hp rating is given at some speed, rpm, that is also typically peak hp, which is not the same rpm as peak torque.

 

Imagine two engines a 6L and a 3L which we have magically been able to make identical in every way (all of the inefficiencies, heat losses, leakage, and etc.). If the 6L generates 409 hp, peak at some rpm, the 3L would need to spin at twice that speed to generate the same hp. In reality this does not happen for a variety of complicated reasons (e.g. the friction of a piston oscillating at twice the speed would go up dramatically). Additionally, It is far more difficult to get something to reliability run at 6000 rpm than 3000 rpm.

 

It is not an impossibility, but I suspect the cost of this is far too high at this point for such a low volume market. The auto industry has the massive advantage of volume which allows them to incorporate more advanced systems, engineer the cost out, and amortize that cost over the many millions of units sold annually. The marine industry, particularly the inboard marine industry, does not have this so they have to be a bit more risk adverse.

 

Pure speculation, but I suspect the marine engine industry relies on the pre-engineered solutions that trickle down from the automotives to make big changes. Smaller displacement engines would be a good place to start. Technically, a diesel solution would be a good one but it seems like that is an even bigger cost hurdle to overcome than spark ignition.

[skier2788]

@Texas6 I think the big issue with a diesel and I am a semi mechanic is

1. Turbo lag would be hard for ZO to deal with. Even you pickup when you slam the throttle down doesn't accelerate like a gasoline pickup until the turbo builds. Hard to pull a skier up when waiting for turbo to spool and tricking could be interesting.

2. Small power band. When I slalom behind a 200 with a 6l I can make it tach over 5k. Diesel will be well out of its power band before then. Could gear it different or prop different but what about hole shot and tricking then?

3. Exhaust gas temps when a diesel is under a load can reach easily 900 degrees. Fiberglass is very flammable. Could be a bad mix. Plus all the extra piping for a cooler would take up room.

The picture below is what happens to a fiberglass truck when the exhaust gets too close to the cab.

Just my opinions.

[skier2788]

Almost forgot diesel hates water in fuel. Could become a big maintenance item for some. How many times have you seen the gas can with a rag stuffed in it.

[SkiJay]

The main reason for using big V8's is that they produce lots of cheap reliable torque. Diesel would work, but no matter how clean and efficient they've become, they still don't sound great or smell very good. Getting V8 power out of a smaller engine is easy enough, it just costs more. The near future is probably going to be big efficient V6s because they're cheap to build and reliable.

 

Even smaller engines with a turbo or supercharging would be my preference for the weight benefits. Turbo-lag is simply not an issue for a tug, and water cooling and intercooling couldn't be easier than in a boat. The only time momentary turbo-lag would occur is during the start which would actually be an improvement over some ham-fisted drivers who insist on hitting the skier too hard at the start. And for Zero Off slalom and jumping, the engine and turbo would already be in the sweet spot for instant power response when needed. Super charging is also a great option for smaller engines, offering less power but no lag. It all comes back to cost. You can get over 1,000 bhp out of a 1500 cc four banger with turbos, but it aint cheap.

 

No matter what happens, I'm going to miss the big warm song of our V8s when they're gone.

[Dacon62]

Here is an earlier thread that covered similar topic

 

http://www.ballofspray.com/forum#/discussion/7211/outboard-motor-in-a-direct-drive/p1

[GOODESkier]

I have a snowmobile engine that is 1049cc and 130 hp stock. After adding the turbo I have 270 hp at any elevation........ yup, money can do most anything.........

[skifan]

As many people mentioned it's not just HP but torque as well. Plus you have to consider where in the RPM curve these values are maximized. Most new vehicles with smaller engines making greater power do so at a higher rpm, > 5,000. This is not conducive to skiing where you need almost maximum torque at lower rpm's to get the skier out of the water and you also need solid HP and torque around 3,500 rpm for slalom skiing and jumping. That's why the 6.0 liter small block is ideal for this application. This motor paired with Zero Off is the perfect combination to give a great pull.

 

Unfortunately there is not a more efficient way to produce that kind of power. As many people said turbo engines will be hard to predict and control with the lag, gas or diesel. They already offer a supercharged engine that is big $$, lots of power but not necessarily more efficient.

 

I wish Nautique would finish designing their Electric 200.

[Texas6]

I could be wrong, but I think the electric Nautique was a gimmick, akin to a concept car. Good for showing technical prowess and forward thinking, but not all that practical.

[ForrestGump]

With a properly sized turbo(s), boost response is immediate in a prop driven boat at speed. We've done fuel injected, turbocharged race boats for years, so I do have some background here.

[skier2788]

I agree with the lag not being a big problem at apeed. What about the hole shot? 2000 foot lake or shorter. I Dont think you make 36 mph. Try starting a turbo car in 4th gear. Unless you have some really expensive magic its gutless until the turbo spools. I agree the biggest problem in a boat is having a single gear to do it all.

[ForrestGump]

And this is where my practical experience differs. I also have a significant amount of experience in drag racing a 1500+hp turbocharged drag radial equipped car. I've actually foot braked the car into the beams in high gear and launched it(with dual rear calipers, I could see 7-9psi of boost out of my 98mm turbo on the footbrake and 3step). Guess what, it went damn near as quick using just one gear. Like a 7.85 at 194mph instead of a 7.70 at 191mph(which would be about normal for leaving in low against the transbrake). To the point that on marginal tracks, I'd a lot of times only use high gear. Now, it wasn't as consistent. But it still went wicked fast using a single gear. As far as our drag boat, it would be at full boost in the amount of time it took you to roll into the throttle. Again, it's all about the setup and the turbo sizing.

 

I'm not saying that a turbo motor is the answer. Especially due to the complexity and simplicity requirements for our types of boats. But a turbo motor works really, really, really well in boats.

[E_T]

@ShaneH‌ I will disregard your remarks and replace the word turbo with supercharger. They sound better boosting :)

[Dusty]

They tell me cold fusion is only a decade away- THEN we'll see some torque! Anyone else hearing those voices?... :-)

[MAD11]

@shaneh Not sure anyone but hard core drag racers will understand that last post. By the way, I could of eaten a turkey sandwich during a pass if my old car only ran a 7.70. I did have a little more tire than you though. Anyway, glad were both away from that racing disease. Too dam expensive.

 

Mercury Marine just released some really cool new diesel engines that VW is producing for them. When I saw these during a project I'm doing for them now I immediately thought this could be great for a wake board board boat and maybe even a ski boat someday. Would have to solve all the speed control issues and turbo issues for sure.

 

http://www.mercurymarine.com/engines/diesel/tier-three/4.2L/

[JJVDMZN]

I looked at the specs of the 4.2L but could not compare it with a Mercruiser Gasoline engine (Mercuiser data does not show all the info) so I used the 4.3L MPI (220HP) and compared it to the 3.0TDI (230hp).

The 3.0TDI is 46kg (12%) lighter than the 4.3MPI and gives 10HP (5%) more.

I'm wondering if this would be the case with the bigger engines as well.

 

With the advancement in Turbo Technology, I think that in future the smaller engines will take over.

 

With regards to EGT being high on Turbo engines, the boat is in water, a lot of water, use it to cool it down. A car can only make use of the water in the radiator and ambient air to cool the engine and is doing it successfully.

[pumpinpete]

A few years back (1997? )GM in Australia released a supercharged version of their Aussie v6 similar to 4.3l MPI pumped similar power & torque to a MPI v8. Local marine conversion guys (rolco I think) did a ski boat version.

Saved about 10% on fuel as I remember

Plenty of holeshot. No lag with a supercharger but higher loads on bearings than naturally aspirated

It never really caught on though I don't recall any problems with the engines .

[MAD11]

@JJVDMZN‌ The turbos on those engines are water jacketed and I believe use the same cooling source as the exhaust. The rest of the engine uses closed cooling. They seem to be lightweight and I was impressed by the small size. I'm not an expert on diesels at all. Ski/wake board boats just came to mind when I saw them as a potential application. They are built and completely made marine ready by VW at their factory to Mercury's specs and meet US emission standards. Just thought it was interesting.

[DanE]

@MAD11‌ Diesel engines are dominant in Europe due to our high fuel prices.

The engine you are referring to would probably fill the need of a ski tug perfectly.

Turbo lag is not something you feel in todays modern diesels and there is plenty of power in the right rpm range.

Should use up to 30% less fuel than a gasoline V8 also.

Almost afraid to ask though- what's the price tag on that VW diesel?

[skifan]

Not to mention that diesel in the northeast averages 30-40 cents more per gallon than gas. That seems to negate the better fuel economy.

 

@ShaneH I understand that you can set up a turbo to provide power at the lower rpm range but don't you sacrifice power at the top to do so? Isn't that why many of the small engine turbo guys give it a shot of NOS off the line to get the power up and have the turbo kick in big power on the top? I know that turbos work as the most efficient power adder to an engine but do you think that a 6 cylinder with a turbo has the chance to pull as good as the 6.0 L 8 cylinder?

[ForrestGump]

@skifan Your understanding is old school. With today's technology, that is not the case. Can a 3.0L turbo engine make 400hp and still have good throttle response from off idle to the top of the rev range? That's so easy it's silly. Making 800hp with that 3.0L enginee makes the driveability suffer a bit and making 1000hp makes it suffer even more, but that's not what we're talking about. Making the power with the driveability and skiability would be super easy. But the downside is the upfront cost and complexity, and the backend maintenance and serviceability. This is where the 5.0-6.2L engines shine.

 

Here's my old 4.6L DOHC powered hooptie with a 105mm turbo which made well over 1500hp and still could be driven just about anywhere I wanted. I would drive this to work a few times a week when the weather was nice. I would routinely drive the 40 miles to the track. I even once drove it 200 miles to a race track, raced, and then drove home. Surprisingly enough, I never got pulled over for the parachute blocking the license plate. :)

http://i155.photobucket.com/albums/s320/2gofaster/Race%20Car/turbolx2.jpg

[ForrestGump]

@MAD11 Yes, I extended my retirement age to about 85 thanks to drag racing. LOL

[Texas6]

@ShaneH, That looks really fast sitting still. Is the hood optional with a setup like that or is it just off so you could wrench on it more easily? For the record, I'll take a parachute on my car long before I'll take one on my back - pretty sweet

[SkiJay]

@ShaneH‌ That turbo looks big enough for a Peterbuilt living in the mountains!

[Boat030]

driveability in a car and being able to pull a skier through the course well are very different. I still think unless you could control the waste gates with the speed control to keep the boost exactly the same it wouldn't be a pleasant pull. And by the way, forget the chute on the car or on your back it gets exciting when it's on the back of the boat!

[Greg Banish]

We covered this before... I know I could put together a 400hp supercharged V6 pretty easy. With Electronic throttle, I doubt any of you could tell the difference between it and a naturally aspirated V8 with the engine cover closed other than the exhaust note. Using the giant intercooler resevoir that you're floating on is uber-tempting to the powertrain engineer in me.

 

I'd actually like to put together a ~320hp 4 cylinder that's even lighter and see how that pulls. I'm doing the automotive equivalent of this right now for a training project. I took the 4.6L 4v engine out of a Mustang Cobra and replaced it with a turbocharged 2.5L four cylinder that makes the same (or greater) power. https://www.facebook.com/ecoboostcobra Turbo lag is not an issue with modern turbos and proper system design.

[E_T]

@eficalibrator‌ I'm impressed! but at the end of the day.. its still a 4 banger.. and a ford

[Waternut]

Curiosity has me here. For all you big engine builders...I know a few have mentioned turbos, intercoolers, and V6's. My curiosity starts to peak because I'm wondering if there would even be any difference in weight between a naturally aspirated V8 of today and a V6 with forced induction on a boat. Power, efficiency, and proper power band are a product of design so it's hard to compare apples to apples in that regard...I'm just focusing on weight alone.

 

In a car, I can certainly see the V6 being lighter assuming the engines are made of similar metals. (aka not a steel block and heads on one and an aluminum block and heads on the other) When you start having to cool extra parts that are generating more heat, you're pumping extra water onboard and water isn't lightweight. Sure there is an infinite supply outside of the boat but you do have a finite flow from the raw water pump so the water jackets have to be large enough to cool the intercooler, engine, and exhaust without the water boiling over before it even reaches the exhaust. Heck even in 80-85 degree water, I can smell my old boats exhaust manifolds getting quite hot after running a 1-2 minutes above 4500 rpms.

[gsm_peter]

Technically it is feasible to save on gas using smaller engines not loosing in performance.

Gas cost, environment rules etc will sooner or later will drive us in this direction.

A suitable very small engine with a small compressor plus turbo in serie and efficient steering will be sufficient.

A ball park figure (wild guess) would be type 180 gram per horsepower hour.

 

A waterski boat is designed to run in-efficient in the water.

It takes type 2200 pounds force to run the boat at 35.

An efficient hull could reduce fuel consumption to half......

..... BUT unfortunately lose tracking performance emensly.

I would guess large savings can be done here.

 

Our club boat consume type 10k usd per season in gas so yes we would consider a more efficient boat to save on gas.

Gas is expensive in Sweden....

[Greg Banish]

@E_T I still own a twin turbo 6.2L Corvette too. Does that make me an OK guy in your book?

 

@Waternut The 5.7 that everyone is used to seeing in ski boats is iron block and heads, so there is invariably a lot of weight associated with it. All of the modern DHOC V6's are aluminum block and heads, with both being shorter in length, and often coupled with a plastic composit intake, so there are significant weight advantages to be had. Modern V6's also reliably make 300+hp now too. The addition of a supercharger, intercooler, and its water is really only about 40# difference if it's done right. Cost is the biggest factor in this industry. There's no way to avoid the fact that newer engines cost more than an old 5.7L, but there are undoubtedly advantages to be had in weight, power, and fuel economy.

[Waternut]

@eficalibrator Very good point on the iron blocks. I changed to an aluminum intake when I swapped to gt40p heads. The stock intake on my 86 was insanely heavy! However, I do remember someone discussing somewhere that aluminum heads would be bad on a boat but honestly don't remember his reasoning...or if he even knew what he was talking about. At the time it made sense though. Maybe I can find that again.