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Old    Adam R (wakecumberland)      Join Date: Oct 2007       03-15-2011, 8:15 AM Reply   
This article discusses runabout specfically but our towboats would really benefit from these clean, efficient and powerful diesels. Would you pay another $50 a month on your boat payment for a diesel powerplant? I know I would!

http://www.boats.com/blog/2011/03/ma...for-runabouts/

Old    Baitkiller (baitkiller)      Join Date: Jan 2010       03-15-2011, 8:21 AM Reply   
It would be silver though, not white.
http://www.yanmarmarine.com/theme/ya...K3047B_web.pdf
Old    Adam R (wakecumberland)      Join Date: Oct 2007       03-15-2011, 8:26 AM Reply   
I wouldnt be picky!
Old    Jeff D (Jeff)      Join Date: May 2010       03-15-2011, 8:37 AM Reply   
Quote:
Originally Posted by wakecumberland View Post
Would you pay another $50 a month on your boat payment for a diesel powerplant? I know I would!
I'd have to know more specific terms. $50 for 6 months, yes. $50 for 15 years, no.
Old    Lorrin E (Kaikane)      Join Date: May 2010       03-15-2011, 8:46 AM Reply   
I have this motor in my daily driver...would be an unreal upgrade for any wakeboard boat. It sounds and acts like a gas motor with the low end power of a diesel...and there is almost no odor with the exhaust.
Old    Adam R (wakecumberland)      Join Date: Oct 2007       03-15-2011, 9:24 AM Reply   
Jeff, I'm just referring to the idea of $50 additional payment suggested in the article. Not sure the parameters they placed on a loan but the implication was a few thousand more than a similar gas engine. Maybe $50 on a 5 year loan? That would be $3000 for the diesel upgrade.
Old    Adam R (wakecumberland)      Join Date: Oct 2007       03-15-2011, 9:25 AM Reply   
A few years ago at a Donzi dealer meeting, the company was showcasing one of its 22 Classics powered by a Yanmar inline six-cylinder diesel and pushed along with a little Arneson surface drive. I couldn’t wait to drive it. I thought it would be great with the diesel powertrain.

VW’s TDI 265-6 three-liter V6 diesel will be mated to MerCruiser’s Bravo 1 and Bravo 3 sterndrives.
And it was. Top speed was greater than the 60-mph benchmark for performance boats, fuel consumption was as miserly as you can get in a 22-foot runabout, and smoke was minimal — and that was before low-sulphur diesel was mandated.

But it still wasn’t ready for prime time. Back then, there wasn’t a sterndrive that could handle the torque of the diesel, even the small six-cylinder in the Donzi. Yanmar didn’t make a sterndrive then—though it does now—so the Arneson was about the only thing available to spin a prop. As robust as these drives are, they’re not for everyone.

For starters, the Arneson is a surface-piercing drive, which requires a deft hand to operate. What’s more, it extends far beyond the transom, which can create problems: Surfacing propellers are sharp, and you don’t want your kids to get cut while they’re supposed to be having fun swimming. The props are expensive, and because the Arneson drive is so long, they’re in harm’s way while towing. And docking isn’t as easy as it is with a sterndrive. Like I said, that powertrain in a Donzi 22 Classic was a great idea, but it had its limitations.

Now, I think the industry has advanced to the point where small diesel powertrains are not only possible in a runabout package, but maybe even preferable.

At the 2011 Miami International Boat Show, Cummins MerCruiser debuted a new line of diesel engines produced in a strategic partnership with Volkswagen Marine: an inline four-cylinder, a 4.2-liter V8, and a 3.0-liter V6.

The V6 caught my attention because it’s the same engine used in the Volkswagen Touareg TDI. Having driven a 2010 Touareg TDI for a weeklong test, I fell in love with the 3.0-liter diesel. It’s a real gem. Foremost, it is efficient. The 5,300-pound SUV netted 25 mpg on the highway, and 20 mpg while towing a 4,300-pound trailer. What’s more, it’s torquey, quiet, and clean, already meeting EPA Tier 2 emissions standards. Here’s the best part: It now can be mated to MerCruiser Bravo One and Bravo Three drives, or used in inboard applications with a ZF transmission. That means all those limitations present on that Donzi 22 Classic are a thing of the past.

Available in 225-, 230- and 265-hp output levels, all three TDI V6 engines achieve maximum torque at 2,000 rpm. That means you can twirl a higher-pitch propeller, and that translates to higher speeds at lower rpm. Fewer rpm means lower fuel consumption, something every boater can appreciate. The TDI V6 also is compact. It will fit under the same engine cover as a regular small-block Chevrolet or 90-degree V6 engine.

From my perspective, there’s no downside to installing the TDI V6 in any manufacturer’s runabout. Whether the consumer bites? Likely that will come down to pricing. Unfortunately, Cummins MerCruiser doesn’t release retail prices for its products, in part because it’s largely boat manufacturers that buy them, not general consumers. Now might be the right time for diesel to make a splash in the runabout and tow-boat markets, as long as the powertrains aren’t overpriced.

But consider this: The retail price for a 5.0-liter V8 with a Bravo One drive starts at $19,700, and with catalyst exhaust, closed cooling, and other options it can total as much as $24,400, according to Steve Fleming, communications director for Mercury Marine. It’s difficult to imagine the TDI 3.0 liter costing that much more. If it’s just a few thousand dollars, it would be worth it, particularly if you plan to finance the purchase. Who wouldn’t pay $50 or so more a month to have an efficient diesel under the “doghouse?”

I’m curious what real-world boaters think. Would you pay a little extra up front on the sticker price for diesel power to save on fuel costs every season?
—Brett Becker
Old    Jeremy Byrom (wakerider111)      Join Date: Jul 2006       03-15-2011, 9:25 AM Reply   
The gear guide 2011 alliance magazine mentioned a small tidbit about diesel power. pg81, Rick Correll of Tige says "We are currently in development of diesel power as well as exploring other advanced options"
Old    Cory D (cadunkle)      Join Date: Jul 2009       03-15-2011, 9:30 AM Reply   
I don't finance toys since I think paying interest on a toy or something I can pay cash for is wasteful. I'd be curious to see the dollar cost difference between a 454/496/etc. vs a diesel, and the price difference after 10-15 years when it would presumably reach a price point I would be content with. Then factor in the GPH with the price of gas vs. diesel along with the annual maintenance costs. Where is the break even point in hours of use when new and where is it when buying used? What are the projected major maintenance intervals and the associated costs? I know I can freshen up or rebuild a gas motor for fairly cheap, but I'm not a diesel mechanic so there would be a learning curve and I don't know what parts and maintenance cost though I assume it's more expensive.
Old    Jason (jason95gt)      Join Date: May 2006       03-15-2011, 9:31 AM Reply   
The Diesel option has been an option for years in wakeboats, but the price tag is crazy. The VW TDI in an XStar was a $35k option. Ilmor has a new Diesel coming out and I guess we will just have to see what happens.
Old     (67King)      Join Date: Feb 2011       03-16-2011, 5:47 AM Reply   
I think Master Craft had an Audi branded (doubtlessly the same engine) TDI as an option for some of their boats a few years ago? I remember seeing them while checking out their website.

To answer the question, though, I'd take a diesel in a second. I'm a big car guy, my toys are all gasoline, but my daily drivers (MB R320 and Ram 2500) are both diesels. The family truckster (MB) weighs in at about 6000 lbs, and I can still get 28 MPG on the highway. I've gotten 22-ish in the Dodge, and 19 while towing the track car. Same car towed with a 2007 F-150 with a 5.4 was getting about 15.

How that translates into the boating world, I don't know (yet - I'm in the market). If the baseline is 6GPH, and 100 hours per year, that is 600 gallons, say $2400. Well, I'd estimate that would go to about 4.5GPH, so 450 gallons and $1800. $600/year savings in gas which is $50 a month. Seems it would perhaps pay for itself while financing, and one would reap the benefits after the boad was paid off. If cars are any benchmark, resale should be significantly greater. And that is in today's economy - if fuel gets more expensive, it will only tilt more in that favor.
Old    Adam R (wakecumberland)      Join Date: Oct 2007       03-16-2011, 6:40 AM Reply   
All good points 67King. The MC offering was a VW TDI and the price was astronomical ($25K). My guess is that option was really only intended for the Europe market and maybe the exchange rate and fuel taxes over there allowed that upgrade to be a little more palatable? Who knows, but one of these manufacturers ought to be able to source a Yanmar, VW or Cummins for a reasonable premium and offer it for a couple years to see if the demand is there.
Old    Art (rallyart)      Join Date: Nov 2006       03-16-2011, 12:27 PM Reply   
I wouldn't buy one. They smell, are noisy, and can't accelerate as well as a spark ignition engine. It's nice that options exist. It's just not one for me.
I guess that means I'm not getting a lifted diesel truck either, but I can live with that.
Old    Adam R (wakecumberland)      Join Date: Oct 2007       03-17-2011, 6:30 AM Reply   
Art, when was the last time you were in a diesel powered passenger car or truck? Smelly? Noisy? Slow acceleration? Obviously not anytime in the last decade....
Old    Pete (petrey10)      Join Date: Apr 2010       03-17-2011, 8:03 AM Reply   
haha the new diesels are cleaner... just as quiet... more acceleration... and more efficient than gasser... Art ur comment is out dated
Old    Pete (petrey10)      Join Date: Apr 2010       03-17-2011, 8:07 AM Reply   
Two things are holding diesel wakeboats back....

1) Price.... if it costs an extra 5, 10, 15, or 20k then you can take that engine and shove it.... I would pay an extra couple/few thousand...

2) Availability... you gotta be able to have a convenient place to refuel... if there is no place to refuel on the water then you could be in trouble... I tow my boat to the lake and there are 2 stations where I could get diesel on the way to the lake so this doesn't bother me. What does bother me is once im on the lake if I am there for say the weekend I am going to need fuel at some point. As of right now to the best of my knowledge I do not have a way to refuel with diesel on my home lake.
Old    C.I.E. J-Rod (jarrod)      Join Date: May 2003       03-17-2011, 8:14 AM Reply   
The 50$ a month payment should easily pay for itself in fuel savings, if the VW motor delivers the efficiency that I would expect.
Old    Greg Taylor (gregtay)      Join Date: Aug 2008       03-17-2011, 4:51 PM Reply   
I just wish they were using the VW/Audi 4.2TDI motor vs. the 3.0TDI... and an added bonus is these things are heavy!! I have the 3.0 in my wife's Q7 and the old V10 TDI in my Touareg.. great motors that would rock in a wakeboat.
Old    Art (rallyart)      Join Date: Nov 2006       03-17-2011, 11:01 PM Reply   
It was Thursday last week Adam. Slow acceleration is a fact, that is part of my business. Smelly, much less than in the past but still more so than a gas vehicle. Noisy, they can dampen the injector noise and ignition noise but it's still louder. They are efficient as their tuned RPM because that's inherent in the design. They are also heavier because that's inherent in the design. Great strides have been made in diesels but the same applies to gasoline engines.
Old     (67King)      Join Date: Feb 2011       03-18-2011, 4:41 AM Reply   
Quote:
Originally Posted by rallyart View Post
It was Thursday last week Adam. Slow acceleration is a fact, that is part of my business. Smelly, much less than in the past but still more so than a gas vehicle. Noisy, they can dampen the injector noise and ignition noise but it's still louder. They are efficient as their tuned RPM because that's inherent in the design. They are also heavier because that's inherent in the design. Great strides have been made in diesels but the same applies to gasoline engines.
What year and model diesel? I find your observations to be completely counter to what I have experienced as a professional, as a diesel owner, and as a follower of motorsports (e.g. LeMans winners are now diesels, and you hear the wind from those cars, not the engines as you do on their gasoline counterparts). But there was a HUGE change in technology, very recently, that has enabled all of this. Before that change, what you stated was largely true.
Old     (Thrall)      Join Date: Oct 2010       03-18-2011, 7:37 AM Reply   
Quote:
Originally Posted by rallyart View Post
It was Thursday last week Adam. Slow acceleration is a fact, that is part of my business. Smelly, much less than in the past but still more so than a gas vehicle. Noisy, they can dampen the injector noise and ignition noise but it's still louder. They are efficient as their tuned RPM because that's inherent in the design. They are also heavier because that's inherent in the design. Great strides have been made in diesels but the same applies to gasoline engines.
Hahahaha, if it's part of your business then you're doing it wrong, unless we're talking garbage trucks or busses.
My diesel is louder for sure, but only because I straight piped it, took the silencer ring out of the turbo and puleed all the baffles out of the intake. Heck the new pickups you can hardly hear them run and the exhaust just hisses going down the highway.
The little VW diesels are even quieter.
Slow acceleration???? Yeah compared to your everday run of the mill Z06 and Ferrari I suppose.
Old    Greg Taylor (gregtay)      Join Date: Aug 2008       03-18-2011, 9:44 PM Reply   
Quote:
Originally Posted by 67King View Post
What year and model diesel? I find your observations to be completely counter to what I have experienced as a professional, as a diesel owner, and as a follower of motorsports (e.g. LeMans winners are now diesels, and you hear the wind from those cars, not the engines as you do on their gasoline counterparts). But there was a HUGE change in technology, very recently, that has enabled all of this. Before that change, what you stated was largely true.
I agree... if he jumped in my v10TDI the words "slow acceleration" wouldn't come to mind... at all! and loud? My wifes' Q7 TDI is super quite. Smelly?... not at all.. can't even tell the Q7 is a diesel (my V10TDI doesn't use adblue.. so there is alittle bit of a different smell if you start it up in the garage.. not smelly.. but i'll admit there's more than a petrol motor (the V10TDI is a much older design.. the new V8TDI would be more like my wifes 3.0 TDI.
Old    Greg Taylor (gregtay)      Join Date: Aug 2008       03-18-2011, 9:53 PM Reply   
Oh.. and i PROMISE "slow acceleration" doesn't apply here... the Q7 V12 TDI would hold it's own against most sports cars out there... not C06 fast.. but 5.5 0-60 and 112 in 15.7sec is impressive for a 6000 pound production SUV. My V10TDI isn't quite as fast.. but it's still quick and the power is instant.

http://www.caranddriver.com/reviews/...t_drive_review
Old    Joe (ilikebeaverandboats)      Join Date: Jul 2007       03-19-2011, 12:24 AM Reply   
diesels are awesome.
bottom line.... if you dont love torque, you like slow things and most likely drive a smart car.

torque is what will move a heavily weighted boat and a diesel will produce that torque efficiently. We will all use less fuel, the motors will last longer, and we will be able to run even more weight....as long as we pair that turbo diesel with a Variable geometry transmission....but thats an entirely different story and will be the coolest most badass combo for a wakeboat EVER.
Old    Art (rallyart)      Join Date: Nov 2006       03-21-2011, 9:48 AM Reply   
See what happens when you poke a bear. I never said diesels were awful, just that I did not like them and I gave my reasons. If you look at car and boat sales you'll find most people agree with me.
The car I last drove was a GL350 by Mercedes so it was pretty current on technology. I also drove a 500 but it's a gas engine. The Audi is built to different rules than gasoline engines at LeMans and they are intended to make a diesel competitive. Audi does a good job of imaging their car as different by accentuating the quieter nature of a turbo engine. My hats off to them. I've owned several Audis, but none were a diesel. My comments on slow acceleration have to do with equal build factors. You don't have to believe me but I assure you I do know a few things about engines.
Smart Car is a cute comment. Most in Canada are the older smaller ones and they are all diesels. The gas engine was installed because they thought the US market would not want the diesel so when the market opened up to sell to the US the gas motor came to Canada too. Also, it is actually horsepower that moves the boat and not torque. You can multiply the torque of any engine by simply changing gear ratios. To push water over time you need to do work, and that is horsepower.
I think the comment on the turbo and variable transmission are really good. Those factors play extremely well into matching a diesel with a boat. But I bet i'll still have a gas engine.
Old    Adam R (wakecumberland)      Join Date: Oct 2007       03-21-2011, 10:57 AM Reply   
Quote:
To push water over time you need to do work, and that is horsepower.
This is true and relevant for offshore racing boats. Will a diesel powered boat be the fastest boat on your lake? Probably not. Will it be the best tow boat in both pulling power and efficency? IMHO...... ABSOLUTELY.
Old    Joe (ilikebeaverandboats)      Join Date: Jul 2007       03-21-2011, 10:12 PM Reply   
but you are spinning something....that is torque you need....NOT horse power.... the logic of "pushing water over time" is not valid.
Old     (67King)      Join Date: Feb 2011       03-22-2011, 4:26 AM Reply   
Quote:
Originally Posted by rallyart View Post
See what happens when you poke a bear. I never said diesels were awful, just that I did not like them and I gave my reasons. If you look at car and boat sales you'll find most people agree with me.
The car I last drove was a GL350 by Mercedes so it was pretty current on technology. I also drove a 500 but it's a gas engine. The Audi is built to different rules than gasoline engines at LeMans and they are intended to make a diesel competitive. Audi does a good job of imaging their car as different by accentuating the quieter nature of a turbo engine. My hats off to them. I've owned several Audis, but none were a diesel. My comments on slow acceleration have to do with equal build factors. You don't have to believe me but I assure you I do know a few things about engines..
I drove a Mercedes with the same diesel engine yesterday. And the day before. And the day before. Matter of fact, I drive one every day. And before we bought it, I drove a gasoline one. Under hard acceleration, the diesel was quieter and MUCH faster. There is a certain speed/load point where you can hear the diesel, but overall, it is much quieter. Of course, Mercedes dropped teh V8 in the R-class because the market went to diesels. And it is quieter at every level than the A6 Avant (3.0L NA gasoline) it replaced.

Almost all diesels are turbocharged nowadays, not sure what point you were trying to make. As for turbocharged gasoline engines and their "quieter" nature, that applies to anyone behind the car, but the whine of the turbo makes them significantly louder inside the car. N
Old     (67King)      Join Date: Feb 2011       03-22-2011, 4:45 AM Reply   
Quote:
Originally Posted by rallyart View Post
See what happens when you poke a bear. I never said diesels were awful, just that I did not like them and I gave my reasons. If you look at car and boat sales you'll find most people agree with me.
The car I last drove was a GL350 by Mercedes so it was pretty current on technology. I also drove a 500 but it's a gas engine. The Audi is built to different rules than gasoline engines at LeMans and they are intended to make a diesel competitive. Audi does a good job of imaging their car as different by accentuating the quieter nature of a turbo engine. My hats off to them. I've owned several Audis, but none were a diesel. My comments on slow acceleration have to do with equal build factors. You don't have to believe me but I assure you I do know a few things about engines..
Hey, you don't have to like diesels. And as with everything, there are tradeoffs. But your reasons were rhetorical balderdash based on 20 year old stereotypes that are most assuredly not true.

I drove a Mercedes with the same diesel engine as yours yesterday. And the day before. And the day before. Matter of fact, I drive one almost every day. And before we bought it, I test drove a gasoline one. Under hard acceleration, the diesel was quieter and MUCH faster. There is a certain speed/load point where you can hear the diesel, but overall, it is much quieter. Of course, Mercedes dropped teh V8 in the R-class because the market went to diesels. And it is quieter at every level than the A6 Avant (3.0L NA gasoline) it replaced. Virtually everywhere diesels are offered, their sales numbers are VERY strong. Take rate on diesels for the F-250's and F-350's exceeds 70%, for example. What do you think it is for Jettas, Passats, and Rabbits?

Almost all diesels are turbocharged nowadays, not sure what point you were trying to make. As for turbocharged gasoline engines and their "quieter" nature, that applies to anyone behind the car, but the whine of the turbo makes them significantly louder inside the car. Never owned a turbocharged Audi, but I currently own two turbocharged (gasoline) cars, and three others prior to those (I've geranally owned a lot of cars, currently have 5 of mine, plus the wife's DD, or 6 in the family).

The point of the LeMans cars was their noise level, but the sanctioning body didn't change the rules to make diesels more competitive, they did so to level the field. Diesels have smaller fuel tanks to counter their improved economy, but within 2 years, it went from all gasoline to all diesel.

As for which is faster, that ALL depends on what build factors you choose. At the end of the day, diesel fuel has more heating value than gasoline, which is why for an equivalent amount of fuel burned, they make MUCH more power. How you transfer the energy from the fuel burned is a-whole-nother set of factors that you can use and tweak any way you want to fit your argument. But at the most elemental level, the fuel itself, diesels have more potential.

I trust you know a lot about engines, it is evident from a few things you've posted. That's all well and fine. I assure you that I do, too, and will be happy to share with you what I've done (all gasoline, interestingly enough). That does not change the fact that each of us is also human, and inherently prone to our own prejudices. Like I said, diesels have their drawbacks. But resorting to calling them smelly and noisy is resorting to old, defunct stereotypes that, quite frankly, make you seem quite ignorant.

On edit - crap, sorry for the partial double post. Hit the tab, didn't reazlied I hit enter earlier, obviously wasn't finished with my thoughts.

Last edited by 67King; 03-22-2011 at 4:46 AM. Reason: Clarification.
Old    Bill Montanye (bill)      Join Date: Feb 2001       03-22-2011, 5:06 AM Reply   
well i heard Epic already has a Hybrid Boat with Diesel as the power plant back up which charges the batterys. They havent released it in a wakeboat yet as it is so heavy they have to test iot in an IO first..they also have an all electric as well.

i dont remember the details but i got the info from epic rep Greg smith i think at the dallas boat show. pretty cool stuff..
Old    Adam R (wakecumberland)      Join Date: Oct 2007       03-22-2011, 6:58 AM Reply   
Quote:
Originally Posted by 67King View Post
What do you think it is for Jettas, Passats, and Rabbits?
I'm pretty sure that in 2010, that 50% of Jetta Sportwagen sales were TDI. Here is a recent media release from VW:

http://media.vw.com/press_releases/v...february-sales

57% of Golf sales in Feb 2011 were TDI

19.6% of all VW vehicles were TDI in Feb '11 (not all models have the TDI Option)

IMHO, diesel will continue to take more market share as people relize its benefits and overcome the 1980's thinking of "slow, noisy and smelly".
Old    Art (rallyart)      Join Date: Nov 2006       03-22-2011, 7:42 AM Reply   
Good post 67King. You are probably right that I could have phrased my first post a little less controversially. I'll stay with gas for the foreseeable future but I really don't have anything against most diesels. I just prefer the characteristics of gasoline for my use. I know a guy who competes in autoslalom very well in an older Golf diesel and does very well. He's fun to watch because he has tuned it to pour black smoke while he runs. It's that poke the bear thing again for him as he knows it's not quite as fast tuned like that. He just wants everyone to be sure they know they got beaten by a diesel. It's all good
Old    Joe (ilikebeaverandboats)      Join Date: Jul 2007       03-22-2011, 8:40 AM Reply   
So for those that still dont think a diesel is a good solution... you probably dont run much weight in your boat, and thats fine, but for me and many others running completely slammed boats a diesel would be the best solution.

If you still think diesels are loud, clanky, slow and smelly, hop in any one of Chevy, Dodge, or Fords new diesels....they are insanely quite, typically produce double the amount of HP in Torque (Look at the numbers on any Tuned diesel in a magazine) and I promise you will be surprised at the acceleration, sound, and how smooth these motors actually are.

Secondly, do all you guys that are against diesels and especially the guy that said you need HP to move water, think that Semi Trucks are used to tow huge heavy trailers for *****s and giggles? TORQUE is what gets things moving, TORQUE is what will spin your propeller, TORQUE is what SPINS things. All your motor is doing is spinning, and on the output there is a force that is resisting that spinning....so a higher twisting force (torque) will overcome a higher resistance to spinning (A heavy trailer pulling back on a steep incline...a propeller spinning through water) and a diesel will do this efficiently. Its why you guys towing with a Gas engine will get less MPG than a guy pulling the exact same boat at the exact same speed with a diesel.
Old    Art (rallyart)      Join Date: Nov 2006       03-22-2011, 9:47 AM Reply   
Joey, you are going to have to take a physics class. I can generate 700 ft. lb. of torque with my lawnmower if it goes through a gear set. As 67King said (in different words), diesel has ha higher BTU content per volume of fuel and hence less fuel needed to generate a particular amount of power. As for heavy trucks you will find that the ones with 500 hp go up hills faster than the ones with 300 hp if they're pulling the same load
Old    Joe (ilikebeaverandboats)      Join Date: Jul 2007       03-22-2011, 10:39 AM Reply   
Quote:
Originally Posted by rallyart View Post
Joey, you are going to have to take a physics class. I can generate 700 ft. lb. of torque with my lawnmower if it goes through a gear set. As 67King said (in different words), diesel has ha higher BTU content per volume of fuel and hence less fuel needed to generate a particular amount of power. As for heavy trucks you will find that the ones with 500 hp go up hills faster than the ones with 300 hp if they're pulling the same load
ill admit to having a prejudice towards torque and diesels, but dont start telling me to take physics classes man! in physics classes, HP is never discussed, only Torque is discussed...because how do you measure HP? You calculate it from Torque.

Its not the same comparison, your 700 ft. lb. lawnmower will not cut anything because it will go so slow due to gearing. You could get a gasser in your boat, gear the thing down to get the torque, but you wont be able to go fast enough to surf or wakeboard. that motor will be wound out and inefficient.

When you look at a HP # it is at the Max RPM or very close to it, on a gas engine if you look at the torque HP curve, this max HP is attained when the torque has already begun to fall off.
Would you rather have a motor that will produce more HP and less torque at a High RPM (more fuel consumption) or would you rather have a motor that will produce more torque with a lower HP at a lower RPM? The lower RPM will allow for greater efficiency and less wear on the motor.


you cant blindly compare HP like this as an argument against torque. Torque is used to calculate HP. here is the equation. Google it if you would like, youll find the same thing.

HP= [(RPM)(Torque)]/5252

it all comes down to the torque curve..... and where torque peaks in terms of rpm.

read this excerpt from this website.
http://www.yachtsurvey.com/GasNdiesel.htm

"Horsepower Vs Torque Another consideration, which many people find difficult to understand, is the relationship of torque to horsepower. Horsepower alone is not the sole criteria of how powerful an engine is. Torque is the amount of kinetic energy the engine builds up as a result of the rotating components -- crankshaft, flywheel and pistons. Torque is measured in the number of foot/pounds of power that is required to stop a running engine at differing speeds (In brochures this is often stated as the "power curve"). Most engine manufacturers provide torque/horsepower curves to illustrate the power range. Diesels, being heavier engines, as well as having more power with each stroke of the pistons, develops more torque lower on the torque curve. Gas engines develop their maximum horsepower toward the top of the curve, meaning the greatest power develops at maximum engine speeds, where it is least useable.

Torque is not a constant, but varies over the power curve, as shown in the graphs for a diesel engine below. Notice how there is a steep rise in the curve, and then how it flattens out near the top of the RPM range. Gas engines have curves that are the opposite of diesels, rising gently along the bottom, and then the curve shoots up sharply.

For heavier boats, the best engine is the one that develops its maximum torque lowest on the curve, meaning that the engine is developing more power at lower speeds. Since lower speeds mean less strain, heat and friction, these factors will translate into longer engine life, just as you will probably live longer with a regime of moderate exercise over a life of hard labor."
Old    Art (rallyart)      Join Date: Nov 2006       03-22-2011, 12:10 PM Reply   
Be confident that, while I can be sarcastic and do make mistakes, I do not 'blindly' compare horsepower and torque. When i make mistakes I admit them. It is the horsepower available at any given point that allows acceleration and a specific amount of horsepower is required to move any given boat at any particular speed.
My lawnmower will pick up a freight train but it would take a very long time. A 300 hp CAT diesel will also pick it up much faster. A little 900 hp F1 engine will actually pick it up the fastest. Now you aren't going to want to do that too often with the F1 engine or the lawnmower but those are the facts.
Power is a force applied for a distance over a period of time. Torque is one part of the equation and, as you stated in my lawnmower example, not necessarily the critical factor.
Old    Art (rallyart)      Join Date: Nov 2006       03-22-2011, 12:15 PM Reply   
Back to Adam's original post...
I think it will be nice when there are a significant number of engine choices. Right now everything for most of our boats is based on the Chevy small block. While it has been a great engine for many years there are other options.
Old    Joe (ilikebeaverandboats)      Join Date: Jul 2007       03-22-2011, 12:54 PM Reply   
Quote:
Originally Posted by rallyart View Post
Be confident that, while I can be sarcastic and do make mistakes, I do not 'blindly' compare horsepower and torque. When i make mistakes I admit them. It is the horsepower available at any given point that allows acceleration and a specific amount of horsepower is required to move any given boat at any particular speed.
My lawnmower will pick up a freight train but it would take a very long time. A 300 hp CAT diesel will also pick it up much faster. A little 900 hp F1 engine will actually pick it up the fastest. Now you aren't going to want to do that too often with the F1 engine or the lawnmower but those are the facts.
Power is a force applied for a distance over a period of time. Torque is one part of the equation and, as you stated in my lawnmower example, not necessarily the critical factor.
I do agree partially, but HP is calculated, based on Torque and RPM which means it is directly related to Torque. If Torque changes, HP will Change, if RPM changes HP will change. HP is a product of manipulating torque, rpm, and a derived constant (5252). Algebraically, yes, you can move the equation around so you are solving for Torque, but what I am saying is that HP itself, is calculated based on Measured Torque and RPM. And HP number you read has been calculated based on the Torque.

Power is a force applied for a distance over a period of time, so how would you utilize that value when talking about the force needed to spin a propeller through water? its Torque that matters here, its spinning and overcoming the drag force in the water.

We are getting into an area where linguistics matters haha, so maybe we can just agree to disagree?
Old    Jeremy Byrom (wakerider111)      Join Date: Jul 2006       03-23-2011, 11:32 PM Reply   
found this http://www.boattest.com/engines/Engi...aspx?ID=440026
Old    Adam R (wakecumberland)      Join Date: Oct 2007       03-24-2011, 7:17 AM Reply   
942 ft. lbs! More ballast please!

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