New Cummins/Mercruiser Project
 

New development with Eliminator...500+hp with 1000# of torque...

http://www.performanceboats.com/html...cummins_01.jpg

http://www.performanceboats.com/html...cummins_03.jpg

http://www.performanceboats.com/html...cummins_02.jpg

Motors are going into this 43' Eagle...
http://www.performanceboats.com/html...4/43rbw_01.jpg

Target delivery is the Ft Lauderdale Boat Show...:cool:

Looks like a great design...also looks like a modified 24v.

I think it will a great start. The 43 Scarab/Eliminator is a good platform. What top end number (80mph) are you guys looking for.:cool:

I wonder what the fuel burn is at a steady 60 mph cruise?

ASD's or #6's?

Can you stagger a diesel boat......never seen it done.

If the engine is 500hp the fuel burn rate is easy to calculate. It takes 1 GPH of diesel fuel for every 20hp. So 500/20= 25 GPH per engine at WOT. I would take a guess that it would burn about 20 GPH per engine @ 60 mph.

how does that compare to say, a 525 at those speeds?

Not sure, but my 6.2 in the sea ray will burn about 25-36gph at wot, I would venture to say the 525 would be 50-60gph

60mph:
Diesels @ 40gph
525s??? will they even push that 43 @ 60mph cruise? @ 60gph? (figuring 1g/mile burn rate, which may be optimistic.)

Fuel consumption averages about .36-.38 lbs per Hp hour. The GPH is based on how many horsepower your using at any given time.

The 25 GPH is close, it most likely will be as high as 28 (dyno) but that "1 GPH of diesel fuel for every 20hp" is probably more representative of what you will see in the actual boat.

Maritime_Eng - that's a very good quick little gauge of fuel consumption, thank you!

Your welcome! After three years of engine development and this is still the most useful thing I have learned.

What transmissions and drives? Also gear ratios?
Ed

NXT

Yes and its been done.

OUCH

cool, a cumminapart :drink:

ok, dumb question. I've just never seen it...even on boats that are always staggard gas setups.

Sure would be neat to have a diesel speed boat that sounded like a loud pipe peterbilt.

Another geezer's 2 cents
 

Joe wassup! Now the top end may be 500 ponies your not gonna cruise with the sticks jammed wide open. For cruise your gonna back it off to a tad under 3200 rpm. Went through the data captures on my laptop. Found one for a QSB 480 cruising at 3175 rpm it was sucking up 20.3 gph. :drink:

So at 60+ mph it would get about 1.6 - 1.8 mpg. Not bad. My Black Thunder at the same speed gets about 1.0 and I always thought that was pretty good for a boat that size.

Is there more info on the engine on a mercury website somewhere?:readinghelp:

That Cumings engine looks cool in that boat.

Thanks Rik

Awesome. 1000lbs of torque each.

I think you guys might be comparing the wrong engines. The 525 ony makes 550 lbs of torque I think. In a boat, the torque number is way more important than the HP #.

IMO, and this might be just a little off, 2 of those mills in a boat would be comparable to 4 - 525's, not 2.

THerefore, the fuel savings numbers would be off the charts.

You don't really see torque numbers like that with engines under 1000HP, and those things drink fuel like it is coming out of a garden hose.

Cummins Mercruiser Diesel Site: www.cmdmarine.com

:drink:

Cruise might be a relative term.. :D I'd love to se some performance specs on that thing, it looks awesome.

Although the diesels are more efficient then 525's they're still only 500hp. The huge torque at low rpm can only be exploited through gearing and propeller selection. The 525's have more hp and are therefore capable of doing more work then the 500hp diesels which will translate into more speed on the top end. Torque aint nothin, without rpm. :cool-smiley-027:

thanks , i saw that site but didn't see these particular engines listed yet ????
Is there a model #, etc??

29 firefox - wazz-up!!!

Nice to have that laptop!!!

I know CMD doesn't have a 500hp, it's a 480 but do they still use the plus/minus 5% or with all the electronics are they able to keep them closer to the 480? I just wondered how they said they're 500's (was it the 5% factor)?

Jeff1000man - I have to back up HaxbySpeed here, I write abut it and have proven it in fact several times with our own diesel race boats Hp = Hp regardless of the source. Why are the turbine boats so much faster? If you went by torque numbers they should be very slow, the fact is they have more Hp and less weight - hence speed.

Torque is controlled through the gearing to give you the optimum propellar speed you need to achieve the mph you want to attain.

Thanks for the info/input....:cool:
Gary

I am understanding.

theres a guy doing it with duramax eng's,and i saw pics of a ''gale banks'' duramax setup

Dan at Team Archer marine built a 43(modified to a 47 due to the attached bung allowing the surface drive) Scarab a few years ago with twin cummins .It has been a great success holding the title for the quickest time from San Francisco to Marina del rey (L.A. basically) . Boat runs about 75 all day long....and great fuel milage.

Who what where & when?:hitfan:

Nice Project Shueman, Keep us updated !!! :drink:


Jon

On that site look up under recreation inboards. QSB 480 hp. The ECM template could be tweaked enough to get 500 ponies but you could only use em for a matter of minutes and Cummins would tear up your warranty.:drink:

Torque is controlled through the gearing to give you the optimum propellar speed you need to achieve the mph you want to attain.[/QUOTE]


Sorry to hyjack the thread Shueman

Joe , I bought 2 ZF 110 TS transmissions with 1,30 in 1 th gear and 1:1 in 2 th gear ,I,m using Yanmar 440 ,s with a pulsedrive unit ,do you think I have made the right choiche in gearing ? Now I can have 3450 rpm propshaft speed in 2 th gear ,oh the boat is a Baja 40 outlaw poker run light weight.
I do not know any weight ,but guess about 10000-11000 lbs ready to go.

According Supertermoli ,he had those yanmars turned up in fuel to make 500+ hp and used them for thousand+hours or so ,with no problems at all.
,I,m going to install pyro,s to keep an eye on things.

I,m still busy with trying to put this whole puzzle together,and hope to be ready next year june .

The props i have bought to start with are Rolla 19 inch diameter and 26 pitch 4 blades cleavers,they are probably to big in pitch ,but I need to make a baseline to start with .

I don,t no nothing about these setups with diesels /ratio /slip etc , what I do know is that all I have learned about gasser ratio/slip etc is not comparable with diesel setups .

A.J

stirling,

We chat on here often on the same threads so I'll tell you what I think straight out. Turn them up to 500hp is fine but when you cruise your probably not making more than 380 hp so that's why they last. Run them at the full 500hp and he's full of crap if he tells you they lasted over 1,000 hours!!!

With that 500 hp at 1:1 at 3450 rpm (I don't know to tell you what props to use as they vary so much?) I know you can run 75 mph with that prop speed without breaking a sweat and cruise at 55 mph forever if not 60 mph and get on plane pretty easy.

For an all around pleasure boat you have great gearing and it will run great and very efficent, I have no doubt.

For Top End speed I always go back to simple math and will fight you on your remark till I die because I did it and proved them to be equal.

"what I do know is that all I have learned about gasser ratio/slip etc is not comparable with diesel setups "

You see all these fast gas boats for sale on here that turn 6,000 rpm's with a 1.33 gear ratio which = 4511 rpm of prop speed.

There is no way to equal 4511 rpm's of prop speed except to equal 4511 rpm's of prop speed. In the case of diesels it's through overdrive gears - simple. There is no magic prop dia or pitch or fancy outdrive or 12 step bottom that will change that fact.

I proved it, Buzzi proved it and he showed me the subtle differences where I went astray but the it remains the same today. I can remember Fabio at Key West in 1988 and me telling him all about my diesels and where we were. He said basically, "Joe, how can you be so dumb as to not realize that you need to trun the same propeller just as fast as the gas boat to go the same speed?"

My response was, "When you put it that way - very dumb!"

Joe Gere

ps with high prop speeds on the diesels comes big problems - the ability to plane at slower speeds - gone! the ability to get on plane quickly - gone! Severe overfueling and smoking to get on plane, if you can get around the fuel control for low boost pressure (firefox will tell us how to rest assured!) and etc, etc. Going real fast with diesels is for race style boats, yours is a great pleasure boat.

now that would be bad ass to see a boat blowin smoke like a lot of the diesel trucks. :drink:

My idea was to bring this boat to +-70 mph ,cause I thought that was the speed the boat could run with the horsepower/torque there is .
from there I tried to calculate back to a prop pitch that I could use ,but I didn,t know what slip numbers to expect.

I know its not going to be a raceboat ,and I use it for pleasure only ,but the things that are most important to me is to go in plane fast, even with full fuel/people,around 70 mph topend ,and
a reliable drive system that can handle the torque.

Supertermoli wrote in older post that he had those 440 up to 500+ ,I believe he had 4 of these in a big v bottem.

I understand what your trying to say with cruising at 380 hp ,and that the 500 hp only is been used at fullthrottle /boost
(and create a lot of heat) ,and during acceleration nobody behind me is going to survive the pollution.:cool-smiley-027:

but asside of that ,your basically saying leave the engines for what they deliver ,because its enough for what I need them for ?

A.J

OK, here's one and with the small 560hp engines in it still - that sure looks like lots of black smoke!!!

Fabio wasn't dumb like me, he dumped all the exhaust under water on his boats so couldn't see the smoke getting up on plane.

Look toward the back all BLACK smoke.

Sounds like a very cool project.People look for the HP#s to go fast.Torque is very important to turning a big pitch prop.