Jassman

I opted for the diesels for a few reasons...#1 fuel economy and I usually cruise more than race around. The problem I had was at 70 to 75 it took longer than I wanted, and top end of 75 was not 80. I had 80 stuck in my head and it was very hard to go backwards from my 04 4300. Also when on poker runs, although the majority of time we cruise, it is nice to know your top end is in the 80's, id always be playing catch up, and that's not what Id want to do is over labor the motors. The mid range was good but you are right, nothing is like these 700's for mid range and top end. I just want my DIESEL cake and eat it too. My point is if the Duramax's are 25-50% more reliable or should I say have appr. 500 hours between intervals at 550-575 hp vs the 750 that Banks is talking about, and is priced like Ive been told, it would be a great alternative.

HabanaJoe

Did you have two speeds in that boat?

What gear ratio did you run?

Michael1

It's not rocket science to determine if an engine will last a certain number of hours. It just takes dynomometer testing, under heavy load for hour after hour. Don't accept anyone's guestimate. Only accept actual durability testing, otherwise you'll be doing the testing.

Michael

vonwolske

Habana Joe:
What is DCA? What do the words stand for? I assume it is a cooling system additive, what brand do you recommend?

Your knowledge is very impressive. Keep posting.

Jim Vonwolske, P.E.
Austin, TX

HabanaJoe

"Diesel Coolant Addititve" - DCA is a borate/nitrite based additive. DCA4 is a phosphate, nitrite and molybdate based additive.

We used Fleetgaurd brand because the trucks had water filters on them and the DCA charges were built into the filters. And yes, diesel should use water filters if they are expected to see a long service life. On marine engines we just used the Fleetgaurd liquid additive.

There are Caterpillar antifreezes that have DCA's in them mixed at the right amount per gallon.

You need to check with your manufacturer and see which you should use also certain antifreezes could be problematic when DCA is added- again check manufacturer first.

Thank you for the compliment, at our peak the combined trucking companies did 17 million miles a month! You learn real fast what works and why or you loose lots of money! One cent a mile savings is an extra $170,000 a month to put toward a race boat, look at ot that way!!!! LOL

Joe

Jassman

I am not sure but If memory serves me right Adib Mastry and Trond had a 1.19 or 1.21 ratio or something like that. No 2 speed trannies. We tried rolla props, 5 blades, and even 6 blades Merc's.
The boat that Nortech brought to the Miami show this year is the same one that was featured in this months PB mag. It is a 39 Nortech which is really a 40.6" boat that weighs approx 11k vs my 07 45' Nortech weighing in at 15k. The speeds of the 39 are now at 82 vs powerboat tested at the time 80. So in all with the weight diff. the speeds of 75 are good. That is why I said 550-575 if the Yanmars were able to be turned up a bit like the mechanical 440's would do the trick. ALSO my 08 45 Nortech is vacuum bagged and has a different layup, and is closer to 13k-13500k with the 700's and #6's. A big weight difference that would possibly gain a few mph. I didnt want to chance it just to gain 2-3 mph so they set me up with the 700's which have been awesome to date. BUT I still am a fan of the diesel program, just trying to mate the right set to another Nortech. Jeff

HabanaJoe

First, I just don't agree with that gearing. All my experience and watching which diesel boats are fast and fast in all conditions says spin the props faster for better performance overall at the higher end of the speed spectrum.

There are trade offs to that which RIK points out and he is right. With small dia props the boat will generally accelerate quicker in the top speed ranges and have much less stress on the drive train when your leaving and re-entering the water. The down side is you won't stay on plane below 50 mph to have midrange you need dia to carry that boat weight.

ex: the 38 Buzzi we ran, 600 hp Seateks (maybe?), 3,100 rpm's, I think .83:1 ratio (17% OD) and 14.5 dia props. The boat could run 92 mph but could not stay on plane under 55 mph, you either idled or hauled ass.

If I read what you wrote correctly the new Nortech is 4K lighter and that is good for 5-7 mph maybe just because of weight/size? I think you had the 440's in your boat and you wanted/needed 550 -575 hp? If that is correct than:

If I were building a boat like you want to, get a pair of Cummins QSC's they're 600 hp, 2 speed trans w/ .87 gear and use like 16" props(?). I don't think you'll gain more than 1,500 lbs over the Yanmars? You have stock engines that are "real" diesel engines and will last thousands of hours at that rating?

That will probaly put you in that 80 mph bracket? - I leave the speed up to RIK if he sees this, his math is good!

Does that make sense or did I miss what you said?

Njawb

Less. The pair of Cs would be 1128 lbs. heavier than a pair of 480 hp Yanmar 6LY3-ETP. For comparison sake, a pair of MarineTech Duramax would be 1350 lbs. lighter than the Cs.

HabanaJoe

There you go the "C's " should work!!!

Njawb - I understand your point about the Duramax and agree with you, it would be nice!

I want to just make one more point about the whole Duramax subject and I don't want to sound like a D**K again.

My argument is that, even if Marine Tech were to be able to make those engines and they had some degree of durability - there will be no warranty centers for them. Should Jassman build a boat with them and decide to go from Fl to OC, MD by boat and it breaks down in NC - who will fix it? The Duramax will be made with special hand made parts that no else in the world has access to.

When you buy a gas engine from any builder including Mercury they all use off the shelf parts. You can argue that they may fitted or clearenced for that particluar engine but non the same - they are start as stock base items off of some large manufacturers shelf.

The Banks engines are literally hand made just like we "made" Cummins hi-pro engines. We made billet rocker arms from a block of alum, we made titanium piston rods from a solid block, we made flywheels, we made piston inserts from 4130, we made manifolds - all of these impossible for almost any engine builder/repair shop to ever duplicate.

All this means is Jassman's $700,000 boat sits in NC for months till it's fixed. Techs fly back and forth, parts are made, etc, etc it takes time.

So, when you ask me why "down" on Duramax, it's there is no existing replacement parts industry to support those or similar custom diesel engines.

I spend $700k on a big diesel boat performance boat, I want to cruise the Bahamas with no worries, I want to run up and down the intercoastal and travel to Poker Runs on my own bottom - if I want to and if it breaks someone can come and fix it in reasonable time. All these things are more than likely never going to be possible with a little local engine shop makeing a hot rod Duramax.

Again, I have no bone to pick with the Duramax itself, it is a great engine!!!

I guess my view having been on the manufacturers side of the table and seeing all the objections, forces me to look at the whole project and not just the point that "it put power out on the dyno so we now have a saleable product" view.

Jassman

http://www.bankspower.com/miami-boat-show-2008.cfm

Doesnt that motor look awesome CLICK ON ENGINE SPECS AND PHOTO'S.

Seriously to awnser your questions, I did have the same Yanmar Motors, the electronic 485hp vs the Mechanicle 440's. The ratio, like I said I was not sure. As to the Cummins, that is alot of weight but with a much lighter and vacuum bagged 43 would offset some of the additional weight of the Cummins....BUT....HOW WELL will the boat run with a lower peak rpm vs the Yanmars at 3400 rpms, Thanks Jeff