cats & turbo diesels
 

Anyone has done a cat with diesels???

yes, one in st. pete .
old tommy bahama has diesels now.

how was is set up

seems 600's are too small for that size what speed are we talking

keep in mind a 600 HP duramax has almost 1000 ft lbs of torque at its disposal... which is about the same torque as a 1075 merc...... SO its safe to say that the boat ran comparable to atleast 850's or perhaps a bit more..

Should solve the problems of stalling at idle and meeting legal decibel limits...

I've heard the 800's are the way to go but they will be available in one year or so...with #6

Anyone have any clue how much the 600's or 800's will be priced around?

anyone has done seateak with arnesons??

I have some experience with Seateks in a Buzzi cat with Tri-max drives - what's your question?

Also, when people are talking about "Duramax" @ 600 hp, do you mean the little GM diesels from the pick-up trucks?

Yes, this months hot boat magazine has a very interesting article about a conversion by imco.

question is seatek 750s with arneson or what other work best with what tranny and prop to obtain what speed in a skater 40

Where can I find info on the duramax diesels and the marinization process? Are they ready for prime time? What transmissions are being mated to the duramax's?

Thanks,

T

I know there are 3 shops working on this project in all U.S,in florida,ca and another in midwest,its not ready yet til at list one more year and will work with sterndrives.If you're interested in findind out more inovation marine in sarasota is one of the shops.

Matador,

I'll give my 2 cents and I've been accused on here of being "not relevant" but I think the Arneson is as good of a drive as you can get. We built test boats (patrol) with Arneson and Trimax drives, the Trimax's are hard to steer, when you get in the marina you needed to steer the boat with the engines as the steering was non-functioning.

The biggest advantage they (Trimax) had was the built in tube to vent the props that worked much better than anything we could rig onto an Arneson.

As far as gear ratios, I'm going to catch flak here, but our boats were designed to run in the open ocean, top speed not as important as being able to throttle the boat and not loose momentum. We used contrary to common practice very high overdrives and very little props.

The Gancia dei Gancia ran a 1:1.5 overdrive and a 14 1/2" dia prop.

I personally do not attest to the diesels have more torque theory and therefore you use different gearing and props based on torque. I believe HP is HP no matter what the engine you have. If a particular gas boat runs well with a certain prop turning a certain RPM, in order for the diesel to make the boat perform equally as well you need to gear the engine to turn that same prop at that same speed. Once you adjust the gearing so the prop speed is the same then a 750 hp gas has the same torque at the prop or into the drive as a 750 hp diesel!

I know that doesn’t answer your question exactly, but take how fast the skater runs with 750 gas engines and figure how much speed you would loose for the added weight and that is speed with 750 diesels.

The Seatek engines, we had the protos to what they build nowadays. The engine itself was very good, the bad points were the cam belt, with heavy throttling they would stretch, when they stretch the vales hit the pistons and you know the rest – change belts often!!! Also we had oil cooler o-ring problem, engines fill with water because the oil cooler were internal to the oil pans. They (race engines) were very low compression, hard to start and dirty, very dirty. From what I see of the new engines, I would buy them.

My arch rival in V was the Doller Marine Apache 41. She was a non-stepped Apache with 1,000 hp engines (maybe). We ran a twin step bottom with a wing, Trimax drives and twin 850-900 hp diesels. The Apache could run maybe 2-4 mph faster than us in calm water – thus HP = HP, gas = diesel

I hope this makes sense to you?

I'll throw in my opinion about "Duramax" engines. If and I say if they are the same as the pick-up engine they can't be bullet-proof as those engines can not compare structure wise to what aftermarket gas engine builders have available. You hot rod those little engines to 600hp or 800hp and they will blow up faster than your gas engines. Time will only tell about this, but history tends to repeats itself.

How are they keeping the rods in the duramaxes, or the pistons together? 800hp duramx on the dyno chunked rods next one pistons cracked. all with fuel only no nitrous added.

carillo has connecting rods and so cal diesel has pistons that will hold up they also have cnc ported heads and cams

Watch Innovation Marines Progress, Seatek Service Center. Fulltime Guys Doing Dyno Work. Was Just There A Week Ago

ah didnt know that socal had the pistons, knew about the heads,cam, and rods how we fixed up the rod part, but the pistons would just piss us off

I like the idea of going diesels,I think its the future, its just a matter of time.its been proven in europe for a long time,and at the rate things are going in the states there is no way out. Gasoline at 5 bucks ,and big motors not lasting more than 100 hours after paying 80k a piece,I think everybody should be looking to develop some bad ass diesel configurations.....

when you were involved with buzzi how did you guys deal with the gear selector foward neutral reverse apparently that's a problem unless i use a crushbox

You're kidding right?

Michael

Two quick notes:

Buzzi boats ran crash boxes that were oil pressurized from the engine w/suction back to engine sump with the offset drop gears on the tail of them. If anyone else remembers when marine engines used to have the gear box mounted on the front of the engine ie Chris Craft/Paragon? Our boxes were like those just on the flywheel side.

Next, if you think Seatek's ran for 100 hrs or more racing your kidding yourself. Average Seatek race engines were what I called freshened every other race, 2 at the most.

Back in the day the story was the Gancia ran the whole season on the same engines, remarkable, no other UIM 1 boat could make that claim. I argued that point with Bonomi and Buzzi until I just walked away. In my mind it was a marketing ploy not a pactical claim. The same engines to them ment the same castings, crank, rods & pistons. Things like cam belts, rings, bearing, valves were all maintenace items - of course those needed to be changed!!!!

Even with that said, in their time they were technology superior to anything else in their CUI range. Alot of what they did wasn't new it was barrowed form larger engines and scaled down or taken from very small CUI gas engines - they just applied those concepts better because their business model was high priced engines to a select few. They never planned or wanted to build 250,000 of them per year.

I've spent millions of dollars and owned 2 fulltime dynos to do just those same things. Just because something runs on the dyno does mean it will run in real life. Dyno's are just a measure of output. How many of you ever used an electric dyno, most are the water dynos which are really recreational units. Electric dynos can drive the engine, load and unload in milli-seconds, you can replicate the loads a truck see while shifting gears and releaseing the clutch. We never did it well but you could have written a program to replicate racing and jumping off/landing waves. Allot of engines break on those dynos that would run great on a water model!

Duramax - it was said they fixed the psitons. Did they go 2 peice pistons or a dissimilar bonded metal?

As far as diesels the way to go, from a saftey stand point absolutely. From a costing standpoint, it has never paid off for smaller boats for the original owner. You don't use the boat enough to offset the additional costs. When your the second or third owner and you don't have to replace the worn out gas engines they you see a savings but on fuel prices alone you can't from day one.

In NJ, diesel costs more per gallon than premium gas, that to me is crazy!!!

Bottomline, I hope who ever is doing these Duramax's does finally bring the oil burners out of the dark ages!!!

Joe Gere

I have always wondered how the limited rpm band of diesel will allow the high speeds that a cat can run. I would think it is hard to gear and prop a engine that has 50% rpm of a gas engine. How do you get to 150 mph at 3-3500 rpm and stlll plane the boat? I will stick to my gas engines for now.

I always wondered the same until I see the overseas Victory and those other teams in which run Lambos or diesels....and those diesels run hard........ for example Buzzi...his race boats run hard..

Brad or lowblue320

How fast do your boats runs and with what gear ratio and at how many engine RPM?

should run good but wont know till a couple of weeks..

“Duramax” The new Diesel Warrior! Light weight, will rev to 41-4300 rpm but will it last at 750 hp and if so, how long?

Habana Joe is got it pretty spot on.

As for what race teams have accomplished, you must realize what is what so to speak.

Yes, a 1200 hp diesel does run great (for a short period of time) against a 900 hp gas engine. What else would you expect. 1200 vs 900, no surprises there. Buzzi typically held a MUCH larger margin than this.

As Hanaba Joe pointed out the diesels are not more reliable when tweaked either. Every time you tweak something, it is going to break, Diesels are no different.

As for RPM's and boat speed. Well that is why Haban Joe said HP is HP.

1,200 hp @ 3,000 rpm = a WOPPING 2,150 lbs of torque. Before everyone says oohhh and ahhh, look at what we have to do that big # to get the boat to perform.

For a Catamaran application: Overdrive the gear box by 1.75:1 and now we have 1,200 lbs of torque to the propeller.

Naturally Aspirated Gas engine, 900 hp @ 7,000 rpm = a merely 675 lbs of torque. Now we reduce this by 1.32 and we get the torque up to 891 lbs of toque.

A 300 hp difference equals a 309 lb of torque (per engine) difference in the boats.

Now the kicker.... Engine weight affects boat weight.

That 1200 hp diesel (SeaTek) will weigh 2000 lbs when it gets into the boat. Dressed Engine, not bare.

The 900 hp gas engine will weigh 950 lbs (remember no blower) when it gets into the boat.

So 309 X 2 = 618 lbs of torque advantage for the Diesel but it has a 2,100 lbs weight penalty over the gas.

Pleasure boating, and not such extremes with the power or the weight will makes things better and closer. But do you compare that 750 hp Duramax to a 525 Merc?

Thank you RIK!

Your right with our margins, the old Gancia with the small engines had 4 X 600hp ea =2,400 hp

It raced against gas boats with 2 X 850hp ea = 1,700 hp

We better go faster or hang it up!!!!

When we re-power Gancia with the twin turbos it was 4 X 900hp ea = 3,600 hp - funny thing was only maybe 8 mph faster, the boat was at it's limits

Thank you again RIK for your support!

then how do you explain a 46 skater(heavy boat)equipped with 750s seatek and arneson drives hits 101 mph???

I recommend a new engine builder, because they are selling you the biggest bunch of cr@p I've ever heard of. If you can't get 1 hp/cu. in. for over two hours on an engine, then throw it away, and get a different engine. Automotive engines achieve that specific output and much more, and they pass 200 to 400 hour WOT durability tests. Even GM's Marine stock engines pass 300 hour WOT tests, and that's with cast parts.

How many hours of durability testing do these marinized Duramax's have? I'm going to guess "none". Almost no one in the aftermarket has the equipment to run long term dynomometer durability tests. They let the customers do their testing.

Michael

gramp we know who you are

That boat went faster than 101. I ran it at 110.

How fast did tommy bahama run ?

I am looking at this strongly for my next application, when ever that may be. The co. in Mich., from what I've been told, (and it's nobody on this thread), are making great strives, and have tested their product thouroughly. I really enjoyed my Yanmar diesel 43 Nortech except the top end number. I even loved those PITA Arnesons:D...just kidding RIK... I prefer the straight 6's for reliability, but am looking forward to the development of these Duramaxes. Right at this moment it is hard to beat these Merc 700's and #6's that I have. I just dont want to trade for a drop in top speed, or even reliability. Just not certain if like mentioned above does 750hp diesel = a 525 boat in performance...Jeff

call Curtis for more info 626-261-0710

Someone answer two question for me?
 

First, I'm not trying to p*ss anyone off I just want to know why & how because I have been out of this for many years and my kids are dragging me back in now(not that it's hard to do!). The world may have passed me by and I didn't even know it!!!


1) If you take a gas engine and build it with an aftermarket block, heads, crank, rods, pistons, valve train assembly, elctronic ignition, etc, etc. and turn it at 5,5000 rpm to make peak HP.

Then you take a Duramax diesel engine with standard block & heads, install an aftermarket crank, rods, pistons, & valve train all most likely from the same people that built the compenents for the gas engine and spin it to over 4,000 revs (the rotating mass has to be lighter than stock to do this) to make peak HP.

Why would the diesel last so much longer than the gas engine and be able to run at WOT so much longer other than it turns slower?

In my mind you have effectivly taken every advantage the diesel had over the gas engine and gotten rid of it (slower rpm + bigger cui + less Hp per cui = longer life)


2) When you talk about running it on the "dyno", we had 3 different ways to gauge or test output on a dyno (I'll list them below). Do you still use the dyno in these ways or have times changed, because each method could produce different number by 20%.

1 - set dyno with a fixed static load and accelerate the engine from idle to full rpm. The time it takes to accelerate that load gives you the Hp output of the engine

2 - adjust load on dyno and accelerate engine until you reach peak Hp, again this is a series of acceleration tests with varing loads, not a steady state for long periods

3 - set engine at desired rpm and adjust load and throttle until the engine starts to drop in rpm, that is peak Hp and then you can back 5% load off of there and run for as long as you want (or things fly around the dyno room)

Thanks, I just want to know am I oboslete in my thinking?

this is what I'm talking about w/750 on a 46 skater 110??? thats sounds pretty fast for 750...I really dont think you can go any faster with gas motors and I.m sure those 750 were realiable....correct me if im wrong...what was the weight and what rpm did you run with what transmisions...........

Rik,then what happen with your theory power to weight ratio that you explained, if 750 diesels(seatek) run 110mph when I doubt a750 gasoline would do that mind 50%less weight then you guys are contradicting yourselves....

They were not set to overdrive like in a race boat.

The boat was HEAVY, like 18-20K lbs heavy. The engines were Seatek 750's which made some 1,300 lbs of torque.

Are they reliable? That is a relative term.

Would a set of big cubic inch gas engines with a blower push the boat to 110. Probably, straining itself. 750 @ 5,000 with a 1.5 gear puts out almost 1200 lbs of torque and then you loose the extra weight. So yea, it'd do it. It too though would be balls out full time to do it.

My point is, there is not magic. Yea there is a lot of smoke and the girls have the mirrors but no magic to power sources.