Sonic30 ss

My boat does 50miles/hours at wot.

but I usally drives at 40-45 miles/hour.

I dont like to push the engine to hard..



In the manual for the engine, it says: do not run the engine at 3600rpm or more for a long periode of time.
it might harm the engine.

I am not sure that that is just a cover your ass claim or...

Another
the great thing is that the engine uses a mercruiser stick to the elsystem, so al the original gauges will work even the tachometer.

and the engine dont smoke at all !! Even when I start her up in the morning.

but she gets a bit dirty in the rear when I have driven for some time, but if you wash rigth after you stopped then it goes off with cloth and water.

I have eddiemarine silent choise, when the exhaust is going thru the transom It rumbles like a big mean gasoline V8.

everybody things it is a V8 gasoline, and is really chokked when I fill diesel on her.

My engine is a Hammer head 300hp
and the price up in Norway is 22400$

the tigershark costs aprox 30000$

this is just for the engine, then you need outdrives and transom.


compare that to a

complete mercruiser pagages up here

Mercruiser 496 MAG.H0,Bravo 1, 425 HP
cost 38857$ in Norway

Mercruiser 5,0 MPI, Bravo 1, 260 HP
cost 24850$

You Know what we buy.

http://www.dbdmarine.com/download/DBD_scarab_256k.mov

here is a link where you can see and hear the engine runs

Kjetil

Thanks for all the info.
That sounds like a great set up.

Im a bit confused. suppose you have a 400 hp diesel and a 400 hp gas engine. given all the weight differences and so forth will top speed be approximately equal? i understand you arent supposed to floor a diesel engine, but even at 80-90% power doesnt the diesel have more torque?

Yes the diesel has more torque.

but the rpm is much lower than on a gas engine.
I am not a an expert on this, but since the rpm on a diesel is much lower you have to put on a much bigger propeller, and the bigger prop is much hevyer to turn in the water. Therefor you will need more torque to turn the propeller.

I think.Thats why it would not go much faster.

As A Said.. Correct me if I am wrong..

There must be a proppeller experts in here who can explain this...

K.J

If the gas engine makes 400 hp at 5200, then it is making roughly 404 ft-lbs. Run that through a 1.50:1 drive, and that give you 606 ft-lbs at the prop at roughly 3470 rpm, but still 400 hp.

If the diesel engine (by coincidence) makes 400 hp at 3470 rpm, then it is making roughly 606 ft-lbs. Run it through a 1:1 drive, and you get, hmmm.... 606 ft-lbs at the prop at 3470 rpm, and still 400 hp.

It can all be equalized with gear ratios.

And: A diesel engine is MUCH more suited to being run closer to it's maximum rating than a gasoline engine is.

Cobra- even if you get the same speed , the economic advantages are clear , less fuel and more longevity.

C-spray,
EXACTLY!!!!!!! Now if you played with the gear ratios on the diesel, say 1.2:1 you get 727 ftlbs and so on, AND you can run @80-90% all day with great fuel economy and many many hours of use.
I'm sorry but a 50 hour tear down( on a big gas blower motor) for an inspection is just not my idea of fun.
It won't be long before we will see lighter weights and higher power from the diesel industry. They see the market and will respond.

As Super Termoli has mentioned before, Hustler has been doing diesels in performance boats for some time, and in a number of their models. The Hustler 40 is a good example. This boat in '95 with triple 350 HP Yanmars 6LY & surface drives ran over 75 MPH; cruised at over 60 MPH at 3000 RPMS; and only burned aprox 37 gph, or 1.7 mpg. This was pushing a 14,000 lb. package. Granted, this same boat with triple 500HP's & Bravo's will push it to a lot more top end. Cruising at 60 MPH with those diesel fuel numbers is something to consider.

It will be interesting to see if diesel becomes more of a popular configuration in the future.

Maybe someone from the insurance companies should add some input here, but the future has to look greater for Diesel powered boats in that the fuel is far less explosive, and the fact that “CURRENTLY” the diesel powered boats are slower than their gas counterparts.

This should make the Diesel boats more attractive in that aspect alone as there is less exposure to problems than with their gas counterparts.

It is a valid issue with the process of the boat insurance companies charging more and more and more. But, if the insurance is as it should be less expensive, it adds even more to the lowered operating cost of a Diesel powered boat.

Sunseeker delivers its XS 2000 with two yanmar 420 hp. This boat did a few Rekords here in Europe.

Twice the amount of torque as a Mercruiser 502...with just under 1000 foot pounds of torque...for starters.The 440 replaced the 420 over a year ago, but is basically the same engine with the boost/fuel pressure raised. Ed