HabanaJoe

If you read my little Cigarette write-up (5-6 pages) that I posted on here some where? (that was dated almost 20 yrs ago) - you will see all your conclusions were validated way back when!

Things haven't changed since then except the advent of muti-speed trans and better control of the diesel through electronics.

Again your conclusions were proven by me almost 20 years ago about overdrives and what a drivelines sees (I know it's just math) and that the boat can go fast.

#4 - is the best method, with some idle problems. The compenstating factor for that is when you run the little props on the Bravo's and you put them in gear the boat doesn't usally move much until you give it a few more rpm's. The diesel can idle lower than the gas and even with OD the prop speed is still pretty slow.

The only part I have to correct you on is that those overdrive boxes don't exist or are hard to make - I have patents on such a box dating back to 1991! We built and tested the boxes on generator sets. Your way to gear and type of gears for such a box is wrong and won't give you what you need, again we have thousands of hours on ours.

The problem, the market just wasn't ready for it. Looking at it today to be honest diesel is $1 plus a gallon more than gas, there is no reason to have diesel in the US from a cost/payback standpoint. I can give many reasons as you all can for it but the dollars outweight the difference usally for the normal boating public.

How do I find what I scanned and put on here and put it back on here again (I'm not were the docs are)???

If anymore would like to re-develope the old boxes, I'm willing to make this into a project and partner up on it? (thought I would just throw that out there!)

Joe Gere

mthill

I didn't find the post you referred to, but it doesn't matter, I know this stuff is nothing new.

I didn't mean to imply that the overdrive boxes never existed, but it's not like I can just go out and buy one off the shelf today. I concede that I haven't thought much about the actual gear arrangement. I'm sure there are many ways of gearing such a device. Having the input and output shafts inline would be nice from a packaging standpoint but not absolutely necessary. I won't go so far as to say what I've suggested is outright wrong...yet.

Are you saying a gearbox couldn't be built to house inline i/o shafts with an overdrive ratio? How is this different than any transmission for built for vehicles. I just need one speed, overdrive. Maybe you're saying there's and easier or cheaper way?

I couldn't find your patent(s) on Google, can you give a reference number?

I found one old thread where you posted some scanned docs, but I don't think this is what you were referring to. http://www.offshoreonly.com/forums/s...98#post2355098

HabanaJoe

That's not the thread, I'll re-post the docs when I get home.

What we built was in-line and ratio's are infinite & nothing is cheap to build one-off's. In production with castings the $'s come down quickly.

Maybe not wrong - too strong of a choice of words, not as durable. In a generator set if the gear box doesn't run 10,000 hours it's a failure so we took a differnt approach to things.

Don't take this wrong, patent has long expired, I wouldn't go into great details on here about any of it without a non-disclosure. More importantly, to me, I would want to build them again or with somebody not just as a special project but with the purpose of bringing it to market.

I hope you can understand that, what I want is simple - a chance to go back remove and a gas engine from a boat, drop in a diesel and not have the extra expensive of new drives, re-doing transoms, etc, etc.

We set out to do that starting in 1985 and thru my own fault never got there. When we had the chance to realize that I foolishly took the path of racing instead thinking we will come back to this later. Things change, later never happens and we should have stayed focused on the pleasure boat market - wow - regrets!!!

Joe Gere

matador

guys, I think its just a matter of time before we'll see new generations diesels;watch its around the corner.Todays technology can not be compared to the 80s or even 90s;things such as common rails etc etc...check out mercedes Benz the new 300E diesel is faster and more durable than the same 300 gas that they make;aluminum blocks and guess what they even achieved same rpms isnt that what we're all looking for?? to move those props.

Michael1

One thing that hasn't changed is diesel engines still cost a lot more to build than gasoline engines of the same power. In fact, with the latest emission controls, the gap may be widening.

Michael

Jassman

I agree...Ill be checking this one out closely...Nortech is now doing a 50-V with the larger 600hp cummins but in a twin application vs the trip 480 Yanmars. Although the motors are heavier as well as longer and wider they are looking for the top end to be close vs the weight diff. between a twin vs trip application. Sea trial in about a month..Looking forward to this as well. Unfortunately, these larger Cummins will not fit in my 43 engine bay without modification, thats why I have to wait for the 480hp Cummins turned up version. Hopefully the Merc Drive will complete the package.

29Firefox

If you buy those Merlins let me know. I 'm used to fast turn around overhauls on them

29Firefox

I've been toying with idea of controllable pitch props like the ones on the big stuff that I work on. Anybody have soem input?

Mentalpause

Do I need to come down and wax your boat again so you can keep it a little longer?

mthill

I understand. It's a project you were/are clearly passionate about and it's too bad it never came to completion. It's amazing how timing can affect the success of a good idea. A lot of things have to happen just right to make it all come together.

I'll get in touch with you offline if I want to discuss the gearbox concept further. An NDA is no problem. I'd like to see the same thing you would, a drop in replacement that won't kill the outdrive. The first one to get that right will have an "in" for this market, Cummins, Yanmar, Duramax, whatever.

The gearbox may find a market on it's own, but it's probably better to come with the engine in most cases. There's always someone willing to piece stuff together, but that's the minority. Most guys don't want to deal with any of the logistics.

It is widening. It's the aftertreatment more than the engine itself...for now. DPFs, SCR, NOx traps, Urea injection, EGR, EGR cooling, etc. On the engine side, Common rail, compound turbos, electric assist turbos, variable valve timing, variable compression ratio, etc. It's ALL expensive, and riddled with compromise.

Most of that stuff doesn't help the burn more efficiently (BSFC), but cleaner. Most real progress is in the name of emissions. A small minority are left to figure out how to use it for a performance advantage. Audi is doing a great job of opening up people's minds with the R10...at least 550 hp, 5000 rpm, no smoke, fuel efficient, and durable. I'll take two...

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