Diesel Refit Dreaming

todd brinkerhoff · Post by **todd brinkerhoff** » Sat May 05, 2012 12:11 pm

About every 6 months, I daydream of refitting my 1991 10.8 Meter International Express with a set of diesels. Because the boat is a V-drive configuration, I need the engines to be the same weight or lighter than the current Crusader 7.4 Liters, because the boat is already stern heavy. The set up is run through a velvet drive transmission and a remote Walter V-drive. So with the new Yanmar 8LV motor, which is a Toyota 4.46 Diesel, I thought I would compare some numbers of my current motor, and two lightweight diesels that I would love to put in its place. I also listed the Torque, Horsepower, and Fuel consumption in gallons per hour with the corresponding RPMS. These are not exact, as I am getting them off a power and torque curve. The most amazing number is the fuel usage. Check it out:

Crusader 7.4L Yanmar 6LP Yanmar 8LVMax HP 350@4400 rpm 315@3800 rpm 370@3800 rpm
Dry Wgt. 1150 lbs 899 lbs 992 lbs

Torque in FT.LBS/HP/Fuel Burn in Gallon per hour.
1500 280/75/Unk 291/50/1.8 368/110/2

2000 345/125/9.6 442/125/3 538/220/3.5

2500 380/175/12.5 516/125/6 590/280/6

3000 415/240/17 501/220/8 583/340/10

3500 420/275/19.1 457/305/12 545/360/15

3800 ------------------ 435/315/16.2 501/370/18

4000 420/325/22.5 NA NA

4400 405/350/25.8 NA NA

todd brinkerhoff · Post by **todd brinkerhoff** » Sat May 05, 2012 12:25 pm

Sorry, the numbers all ran together, I'll break them down:

Crusader 7.4L
Weight - 1150 lbs
Max HP - 350@4400

Torque in lbs/Horsepower/Fuel Consumption in Gallon per hour:
1500 280/76/unk

2000 345/125/9.6

2500 380/175/12.5

3000 415/240/17

3500 425/275/20

4000 420/425/22.5

4400 405/350/25.8

Yanmar 6LP
Weight 899 lbs
Max HP - 315@3800

1500 291/50/1.8

2000 442/125/3

2500 516/125/16

3000 501/220/8

3500 547/305/12

3800 435/315/16.2

Yanmar 8LV
Weight - 992 lbs
MAx HP 370@3800 rpms

1500 368/110/2

2000 538/220/3.5

2500 590/280/6

3000 583/340/10

3500 545/360/15

3800 501/370/18

Cruising Speed Comparison

Crusader at 3500 rpms is 420 ft/lbs, 275 HP, burning 20 gallons/hr

Yanmar 6LP @2500 rpms is 516 ft/lbs, 125 HP, burning 6 gallons/hr

Yanmar 8LV @2500 rpms is 590 ft/lbs, 280 HP, burning 6 gallons per hour

jefflaw35 · Post by **jefflaw35** » Sat May 05, 2012 4:43 pm

good luck with this Todd, That shoot just hurt my brain!!!! I love to day dream, Im sure you can tell!!! this will be a neat thread to follow, as I really wanna steal your boat, oh I mean l really like your boat!!!

cant imagine the cost to swap out motors on this beutiful floater! Boats are more addicting that drugs! IMO

gettaway · Post by **gettaway** » Sat May 05, 2012 5:29 pm

Have you figured out what it would cost to repower with said engines?

Commissionpoint · Post by **Commissionpoint** » Sat May 05, 2012 9:31 pm

or these.....

http://www.cmdmarine.com/Product2/4.2L/4.2L.html

prowlersfish · Post by **prowlersfish** » Sat May 05, 2012 10:11 pm

VW chain saw diesels ugg

summer storm · Post by **summer storm** » Sat May 05, 2012 10:22 pm

todd brinkerhoff wrote:Sorry, the numbers all ran together, I'll break them down:

Cruising Speed Comparison

Crusader at 3500 rpms is 420 ft/lbs, 275 HP, burning 20 gallons/hr

Yanmar 6LP @2500 rpms is 516 ft/lbs, 125 HP, burning 6 gallons/hr

Yanmar 8LV @2500 rpms is 590 ft/lbs, 280 HP, burning 6 gallons per hour

I love diesels but for me the numbers just don't add up

my 360's burn 20 gal per hour at 2,500 and 27 gal per hour at 3000.

If I take the diesle burn (12 for both) and subtract the high gas burn (27) and subtract the difference I get a 15 gal per hour savings. 15 gallons saved every hour will equal 75 dollars that stays in my pocket, current dollars.

lets say I find a very good deal and the repower only costs me 30K, so to really start seeing the cost benefit I would need to run the boat 400 hours at cruising speed, not idle. For me that equals 6 to 8 years.

I guess you can get those numbers down if you repower with cheaper, used engines but I am not a big fan of spending 15K for something that a week later can cost another 5K in repairs.

Again, I love diesels, the yachts I run (of course) have big diesels, and they run great.

Commissionpoint · Post by **Commissionpoint** » Sat May 05, 2012 10:30 pm

prowlersfish wrote:VW chain saw diesels ugg

http://green.autoblog.com/2010/08/16/cu ... ne-diesel/

prowlersfish · Post by **prowlersfish** » Sat May 05, 2012 10:38 pm

Commissionpoint wrote:
prowlersfish wrote:VW chain saw diesels ugg
http://green.autoblog.com/2010/08/16/cu ... ne-diesel/

Still VW chain saw diesel

And the Cummins Mercrser deal is over . ( that link is old) the have parted .

The latest http://www.cmdmarine.com/
"Cummins Inc. and Mercury Marine have transitioned from their Cummins MerCruiser Diesel (CMD) joint venture to a strategic supply arrangement between the two companies to more effectively serve customers in the global diesel marine market. Cummins and Mercury will each utilize their respective parent company resources to develop, manufacture, sell, distribute and service diesel engines, drives, pods and related parts, accessories and services. For information on diesel engines from 5 to 15 liters click through on the Cummins logo. For information on diesel engines below 5 liters, drives and controls please follow the Mercury Diesel logo.
"

jefflaw35 · Post by **jefflaw35** » Sat May 05, 2012 10:46 pm

fuel cost is killing our fun! Im kinda glad that im just a little boat guy, you guys have issues LOL

RWS · Post by **RWS** » Sun May 06, 2012 8:29 am

I am running the 6 LP's

the refit upgrade only makes sense if you are in need of REPLACING the existing engines.

My engines were tired and the bolt on components had not been properly cared for by th eprevious owner. Heat exchangers, oil coolers, etc would have to be replaced if I chose the rebuild route.

Once adding up those costs, a pair of new Crusaders 8.1 electronic style made more sense, but according to Crusader I would have to replace my shafts and raw water system.

NOW the DIFFERENCE between the NEW Crusaders and the diesels became much closer.

Correct prop selectuin for WOT and Meticulous maintenance is the key to
longevity and long term efficiencies.

a higher, more efficient cruise speed coupled with the increased level of safety are benefits that don't show up on any calculation, as is the higher eventual resale value and the quicker sale once on the market this vessel will command. Of course, I'll be dead by then so that won't benefit me in the least.

RWS

RWS · Post by **RWS** » Sun May 06, 2012 8:44 am

summer storm wrote:
todd brinkerhoff wrote:Sorry, the numbers all ran together, I'll break them down:

Cruising Speed Comparison

Crusader at 3500 rpms is 420 ft/lbs, 275 HP, burning 20 gallons/hr

Yanmar 6LP @2500 rpms is 516 ft/lbs, 125 HP, burning 6 gallons/hr

Yanmar 8LV @2500 rpms is 590 ft/lbs, 280 HP, burning 6 gallons per hour
I love diesels but for me the numbers just don't add up

my 360's burn 20 gal per hour at 2,500 and 27 gal per hour at 3000.

If I take the diesle burn (12 for both) and subtract the high gas burn (27) and subtract the difference I get a 15 gal per hour savings. 15 gallons saved every hour will equal 75 dollars that stays in my pocket, current dollars.

lets say I find a very good deal and the repower only costs me 30K, so to really start seeing the cost benefit I would need to run the boat 400 hours at cruising speed, not idle. For me that equals 6 to 8 years.

I guess you can get those numbers down if you repower with cheaper, used engines but I am not a big fan of spending 15K for something that a week later can cost another 5K in repairs.

Again, I love diesels, the yachts I run (of course) have big diesels, and they run great.

======================================

o.k

let's use that $30,000 number with the following assumptions:

Th eboat will be worth AT LEAST half that difference at resale

i will keep the boat for ten years

Repower cost of $30 less the (assumed dirty number) $15 additional value at resale equals a cost of $15,000 spread out over ten years equals $1,500.00 per year.

add to that the inctreased usage as you will be using this more efficient and reliable vessel more frequently and covering more places to go things to do etc plus the safety factor.......

now it makes a bit more sense, but ONLY if the existing engiones are at the end of thier service life.

RWS

prowlersfish · Post by **prowlersfish** » Sun May 06, 2012 10:49 am

There is more to more to a Diesel boat then the fuel savings a lot more . Safety and reliability to start with . And a feeling and confidence you have with them ,something you can't under stand untill you have one .

Yanmar make a great set up as do Cummins ( not the rebadged VM or VW ) and Volvo and CAT

With that said there are some poor diesels out there Mercury sold and later put the Cummins sticker on VM (Italy ?)based diesels a lot of issues with them an no support . very light duty and pushed to their limits in marine use. The merc dealers where not diesels guys and the Cummins guys did not what to work on them as they where not a Cummins product .And parts take forever to get ( months ) and cost dearly .

That VW diesel faces the same problems with support . Many Mercury dealers won't work on them .hopefully parts will be available .Cummins is no longer involved . Time will tell how the hold up in marine use

todd brinkerhoff · Post by **todd brinkerhoff** » Sun May 06, 2012 11:11 am

jefflaw35 wrote:good luck with this Todd, That shoot just hurt my brain!!!! I love to day dream, Im sure you can tell!!! this will be a neat thread to follow, as I really wanna steal your boat, oh I mean l really like your boat!!! cant imagine the cost to swap out motors on this beutiful floater! Boats are more addicting that drugs! IMO

Thanks Jeff for the nice comment!

As far as costs, the refit costs for diesels will make you either laugh or cry, and as RWS said, it makes little sense if you wee not in need of repowering. To make myself feel better, I needed to do some math.

Suggested retail prices:

Yanmar 6LP is $20,000 plus $5000 vat
Yanmar 8LV is $25,000 plus $5000 vat

Let's for the ease of math say that a repower with the 8LV cost $100,000 after selling whqt I have and having to change out almost everything. And to repower with new gas engines would total $15,000.

Fuel costs:

Gas is $5.00/gallon for non-ethonol
Diesel is $4.50/gallon

Non-ethonol fuel will continue to bring a premium price because it comes from Canada. This will be the biggest question moving forward for gas engines.

For the ease of math, ill assume 100 hours of use in a year and I will use the cruising fuel usage. Obviously, there is some trolling speed, etc. but the difference in fuel burn is still relative.

Gas motor at 40 gallons an hour (2 engines at 20 per). at $5.00 gallon equals $20,000 for fuel for the season.

Diesel motor at 12 gallons an hour ( 2 engines at 6 per) at 4.50 gallon equals $5,400 for the season.

$ 100000 refit minus $ 15,000 refit is $ 85000 more for diesel. With the example burn a year with current fuel costs, gas would cost you $14,600 more a year.

With an $85000 initial coat difference, it would take you 6 years to make up the initial costs.

prowlersfish · Post by **prowlersfish** » Sun May 06, 2012 11:21 am

todd brinkerhoff wrote:
Gas motor at 40 gallons an hour (2 engines at 20 per). at $5.00 gallon equals $20,000 for fuel for the season.

Diesel motor at 12 gallons an hour ( 2 engines at 6 per) at 4.50 gallon equals $5,400 for the season.

Todd I am one of the biggest fan of diesels on the site But the fuel burn Numbers you have are way off . Your not going to go from 40 gals a hour to 12 . Not going to happen .( unless you cut your speed in half ) you may go from 40 to the mid 20s . The Fuel burn hours in your chart are way off .

You can't get 280hp at 6 gal per hour You can get aprox 22hp per gal per hour .