Detroit with sterndrive?

[Northwester]

Originally Posted by gonzo

A DD does not have more torque than a Volvo Penta of similar horsepower. Look at the specifications before posting.

The issue is the RPM at which the power is delivered.

Go ahead and hook up a lower RPM (2500-2800) diesel like a DD or B series Cummins to a Volvo 280 leg and select a higher pitch propellor than what would be used on an equivalent powered gasoline engine which delivers peak HP at 4500 RPM to acheive the same vessel speed and see how long the upper gear set will last in a planing hull application.

[StianM]

Originally Posted by Northwester

The issue is the RPM at which the power is delivered.

Go ahead and hook up a lower RPM (2500-2800) diesel like a DD or B series Cummins to a Volvo 280 leg and select a higher pitch propellor than what would be used on an equivalent powered gasoline engine which delivers peak HP at 4500 RPM to acheive the same vessel speed and see how long the upper gear set will last in a planing hull application.

Don't start to confuse torque with power.
And the gearing in the sterndrive can also be altered not only the pitch.

[Rik]

It all comes down to the torque of the engine and the reduction ratio in the out drive or marine gear. When converting from a Petrol to a Diesel engine there is also a few more things to factor in as they are not the same thing.

If you want performance, then weight is everything and the DD is not favorable in this area. Look at the Styer, Cummins or Yanmar.

169 kw @ 3,000 rpm is a small motor (225 hp) and thus a Bravo has a higher chance of surviving this but anything more than 250ish in diesel power leads to high maintenance.

[Northwester]

Very well then. I will stop being confused about torque, power and horsepower for the moment.

It would probably be helpful to discuss the intended application of the 400HP DD engine connected to stern drive.

What is the intended application in terms of vessel length, vessel hull type (planing, displacement, semi-displacement) and vessel weight?

[StianM]

Wondering if the 4-53 with larger injectors would be better?
The v6 just weigh a litle too much, but the sound is sweet

I would like a steyr, but they are quite expensive and a litle too ordenary.

[Bglad]

Originally Posted by StianM

Wondering if the 4-53 with larger injectors would be better?
The v6 just weigh a litle too much, but the sound is sweet

I would like a steyr, but they are quite expensive and a litle too ordenary.

What about the GM 8.2 (litre) four stroke diesel. It was used in trucks and was marinized too but didn't last too long due to longevity reasons (my understanding) but in a relativey light duty pleasure application it might be good. I installed a few in place of gas engines when I had my shop in the Florida keys. 220 hp 1560 lbs fully mairinized from DD specs.

[StianM]

Originally Posted by Bglad

What about the GM 8.2 (litre) four stroke diesel. It was used in trucks and was marinized too but didn't last too long due to longevity reasons.

Sounds like something regular. A commer might be a option if I could find one.

[gonzo]

Gears are rated for torque and not horsepower. Horsepower is measured as a function of torque at a certain RPM.

[Northwester]

There's a DD 16V149TIB listed for sale eBay right now with a Buy It Now price of $24,000.00 USD.

That engine weighs 12,000 lbs so at $2.00 a pound that's a pretty good deal.

I'm sure it sounds really sweet too!

http://cgi.ebay.com/ebaymotors/16V-1...item588ac5c5b5

[whitepointer23]

Originally Posted by StianM

1 metric ton!!! From the data I have found they weight 600kg witch is also alot, but I could live with it. 1 ton on the other hand.
I was looking at bravo drives and they deliver diesel drives up to 320hp, but I'm not sure what propeller RPM I should have.
I can't find data for pitch and stuff like that so it's not so easy.

i think 1 ton would be right, i had 2 453 turbos with b/w 72 's and they weighed 750kg each. a 280 should easily handle a 653 , you could get a custom prop made. i put a hardy spicer driveshaft from the engine to leg in one boat which worked well and got the weight off the transom. a dana leg is an option if you can find 1, they are almost indestructible. i know of a seatiger leg here in perfect condition , a bit far away for you though. i love detroits, with a sound that good you ignore the oil leaks.

[Carteret]

I love them too. They are heavy and not as efficient as the newer engines, but they are dependable and tough!

[IMP-ish]

Did you run this by Konrad?
http://www.konradmarine.com/