High performance diesel

Comanche3Six · 05-01-2006, 01:52 AM

With the rising cost of high test gas in the USA, I have been considering converting to diesel power for the Comanche. Since this is not a common practice in the USA, I feel this question could be better answered by the crew of BoatMad.

What high output diesel engines do you recommend?

What transmissions?

What Sterndrives, gear ration etc?

The Comanche is currently fitted with Big Block Chevrolet power. Borg warner transmissions.
Mercruiser SSMIII drives 1.50 gear ratio

Thanks
Ed

I have got my eye on these konrad 540 drives

http://aolsearch.aol.com/aol/redir?s...e+In+The+Water

Jon Fuller · 05-01-2006, 09:02 AM

Ed,
It's going to be hard to emulate your current Gas setup, at least it is with motors that are cost effective, and that will fit in your existing engine compartment.

Yanmar do some very nice 5.7 litre, in-line six diesels, which are a tad heavier than your BB's, but are only 440hp stock, and maybe 500hp 'tweeked'. You may be able to get them to work with Konrads & Borg Warners, but you're gonna be taking a sizable pay cut in performance.

Seatek build monster power diesels, up to around 1300hp, but they are huge, and heavy (around 1700lbs each). they also produce transmission crushing torque, and and low RPM's, so you 'might' get away with #6's! but III's, #4's, Konrad's etc. would crumble at the sight of one. they're also hugely expensive, and sinse their exclusion from UIM Class1 racing, the company's future is I believe unsure.

Also, most of the big power diesel (read, racing type) are relatively high maintainance, noisy (in a diesel kinda way) and smelly/smokey, I really can't imagine it would be much of an exchange for blown gas V-8's

So to be honest, replacing 800hp, half ton, compact V-8's aint gonna be easy.

A 25oz 'beak' with some lightweight diesels like mine, or from Yanmar might go ok, but I shouldn't think that'd be 'your bag'!

With diesel, there seems to be a critical mass, beyond which there's little from the regular engine makers that will cut the mustard.

I have a dream of building a 33' version of my boat (keep getting promises from the builder, of drawings for said boat) which if it ever happens, and we maintain our tax exempt diesel here, would get the yanmars, or the supercharged 410hp versions of my GM's, and would probably manage around 70mph, not enough I suspect for you, but my point is, as soon as you go above this size and weight, the options disapear for practical diesel motors.

Sorry I can't be of more help.

Jon

Adam · 05-01-2006, 09:08 AM

Not much help at the moment - but it is going to be very interesting to see where diesel power is leading.

There have been so many developments in recent years from the Automotive side.

See that Audi are trying to win the Le Mans 24 hours with diesel power this year!

Lars T · 05-01-2006, 03:14 PM

Quote:

Originally posted by Adam See that Audi are trying to win the Le Mans 24 hours with diesel power this year! [/B]

With Tom K at the wheel they would win it with a LPG car

Comanche3Six · 05-01-2006, 09:44 PM

John
How durable are the yanmars?
Would a two speed trans help?
Engine price?
What is the best gear ratio for the outdrive?
Thanks
Ed

Is this the unit?

http://www.yanmarmarine.com/products...A_TechData.pdf

Comanche3Six · 05-01-2006, 11:32 PM

Well Jon,

I just received a lesson in economics! I called Tom at Warlock Marine and discussed Duramax diesel marinization, torqueflite 2 speed trasmission marinization and two new Konrads. Not to mention a total refit of the Comanche. And here is what I learned.

High test gasoline really isn't that expensive after all!

Thanks
Ed

Jon Fuller · 06-01-2006, 12:42 AM

Quote:

Originally posted by Comanche3Six
Well Jon,

I just received a lesson in economics! I called Tom at Warlock Marine and discussed Duramax diesel marinization, torqueflite 2 speed trasmission marinization and two new Konrads. Not to mention a total refit of the Comanche. And here is what I learned.

High test gasoline really isn't that expensive after all!

Thanks
Ed

Interesting!

What power/torque are they getting from the Duramax?

Matt · 06-01-2006, 12:52 AM

That's amazing the variation in power dependant on FUEL temperature!

Quote:

Originally posted by Comanche3Six
John
How durable are the yanmars?
Would a two speed trans help?
Engine price?
What is the best gear ratio for the outdrive?
Thanks
Ed

Is this the unit?

http://www.yanmarmarine.com/products...A_TechData.pdf

rama · 06-01-2006, 01:09 AM

Matt You pick up on a very valid point here, My 200's were aparently onlu producing just over 175 hp you have also to read a lot into the small print + different speed ratings to realise that they can sell you engines that dont do what you think they will.!!!!!!! (but i still like the yanmars anyway)

Comanche3Six · 06-01-2006, 01:20 AM

Quote:

Originally posted by Jon Fuller
Interesting!

What power/torque are they getting from the Duramax?

Tom stated "800 hp easy"
He has achieved it already...and it makes a nice replacement for the Big Block Chevy. He is a very knowledgable man on this topic.

http://aolsearch.aol.com/aol/redir?s...tle=WPM+RACING

Jon Fuller · 06-01-2006, 01:30 AM

Wow, that's big power from a 6.6 litre diesel!!

there's no mention on the website of Duramax, or indeed of diesels at all. did he give any idea of prices for various HP duramax's?

I know the base engine is costly, and that currently, Peninsular have no intention of going over to Duramax for that very reason.

I wonder how much a pair of 500's would be?

Comanche3Six · 06-01-2006, 02:46 AM

Quote:

Originally posted by Jon Fuller
Wow, that's big power from a 6.6 litre diesel!!

there's no mention on the website of Duramax, or indeed of diesels at all. did he give any idea of prices for various HP duramax's?

I know the base engine is costly, and that currently, Peninsular have no intention of going over to Duramax for that very reason.

I wonder how much a pair of 500's would be?

He said if you provided the engines....marinization is $5000. He also stated that they did a conversion for GM. and it was very successful, but because of the popularity of the Duramax in the trucks GM just had no interest to take it further. If you get the opportunity call Tom...it is one hot diesel!

Here is a good start!

http://cgi.ebay.com/DURAMAX-DIESEL-6...QQcmdZViewItem

Link is not working...Ebay Item number: 8027432598

Matt · 06-01-2006, 09:17 AM

That's very interesting!!!!

I guess in the short term it's a shame GM aren't interested, but if it's that popular, the production run is gonna be huge which hopefully means the cost, availaibility of spares, and lifespan of the engine in production is going to be decent.

"Obvserving" the european manfr's (Myself and Jon have been taking a look at the VW Touraeg V10 motor), any given engine design seems to have a very short life - plus, they won't sell spares for it. "Not field serviceable" was the phrase used.

Jon Fuller · 06-01-2006, 09:33 AM

Amazing.

We did some research here on boatmad a while ago on the Duramax, and it's definitely one awsome diesel engine, the biggest problems I can see are, because it's a very, very low revving engine, almost back to how diesels were 20-30 years ago, the torque figures are scarey. as standard, 605 ft/lbs at 1600rpm

that's drive breaking torque, even as standard.

For higher outputs, 4, 5, 6, 7> x100hp, imagine the torque! you'd need speedmasters surely?

This low rpm factor also causes trouble with getting gear ratios and prop pitch suitable for high speed.

My GM's rev to virtually 4000 rpm, and I only need to gear/prop for 70 mph. I still have to use the lowest standard ratio Bravo (1.36:1) and props of over 30" pitch. Imagine needing to do 80, or 85 or more, and only having 3000 rpm to play with!

Still, it sounds great!

Another option, was the Volkvagen Touareg V-10. this is also 300hp in standard automotive form, and a far higher revving motor, also very light and compact.

here's the vital statistics listed for the Duramax:

Number of Valves
32

Displacement
6.6L (6,600 cc)

Compression Ratio
17.50:1

Camshaft Configuration
OHV

Horsepower
310 @ 3000 rpm

Torque
605 @ 1600 rpm

Fuel Delivery Name
EFI

Bore x Stroke
4.10 x 3.90

Matt · 06-01-2006, 09:46 AM

Overdrive in the gearbox?

Otherwise, as you commented the other day, even if the drive holds up, the prop pitch is so huge it becomes a paddlewheel! Or you have to increase the diameter a lot, which I guess means even higher x dims are possible, but you still have the mega torque to contend with - oh, and probably custom making your props. Ouch.

Jon Fuller · 06-01-2006, 01:22 PM

Quote:

Originally posted by Matt
even if the drive holds up, the prop pitch is so huge it becomes a paddlewheel!

A feature i've become familiar with this morning

Matt · 06-01-2006, 02:41 PM

Skeg on the propshaft?

Comanche3Six · 06-01-2006, 11:58 PM

These are some very innovated guys.....4 speed transmissions for diesels!!
http://www.weismann.net/offshore.html

Nice drives!
http://aolsearch.aol.com/aol/redir?s...+Transmissions

Toffen · 08-01-2006, 01:16 PM

Hi!

Nortech V3900 with twin Merc EFI 525 and XR drives runs 93 mph
Nortech V3900 with twin Yanmar 480 and Arnesons runs 75-78 mph...

Cheeeers, Toffen G

Comanche3Six · 08-01-2006, 03:12 PM

Yesterday I spoke with Pat at Weismann and he said that they where teaming up with Cummins to get a V8 Diesel to go in front of their multispeed gearbox and sterndrive. That should be a monster combination! Considering the WMD drive is $40,000 apiece, I guess my only alternative is to hit the Lottery to be able to afford the drivetrain. Still interesting nonetheless. Three of those units in a 47' McManus Apache and I'm good to go!