one engine / twin drive setup???
 

is there ever been such a beast or has a branch from the crazy tree broken off and hit me in the head?
Just wondering if theres ever been a setup to hook up a twin drive setup to a single engin? I know that some of the drag boats use a gear system bt i was thinking about having forward and reverse capabilities and being able to still controll shifting of each drive sepperatly. Let me know :)

Yes...Imco was working on one a while ago. I'm not sure what stage it's in right now, but a few magazines had pictures and an article on it a year or so ago. Seemed like a great concept, I suspect you'd beed big power though to spin the main transfer case as well as the two drives. Seemed like a good option for the 28' range boats.

They tested a boat in Powerboat a few months ago with the IMCO setup.

My uncle has one in his Dorado. It has a single volvo diesel and splits the power to twin volvo duo props. Might be good for a fishing boat, I don't see the application in the high performance world. What happens when one drive breaks and you put 100% of the power through the other drive? That's assuming the first one didn't lock up...

Nordic has one of their 21' Blaze ski race boats equipped with the imco splitter system i believe. This is the boat in the ad that you see on the 2 page ad that you will see behind the front cover of many boat mags. I read a review of one about a year ago, but i cant for the life of me remember where. Their website www.nordicpowerboats.com has some pics of the boat, but none where you can really see the drives.

Assuming that they are shiftable drives, shift the broken one into neutral, and take it easy on the throttles - pretty much the same thing you do when you break a Bravo in a twin setup....

While we're at it, my vote would be for a single 1350 Lycoming and a pair of ASD6's in my 38 Formula.

Not being too much of a smart ass, but if you had a single engine-single drive boat you would still be in the same situation - that is if you had a single engine-dual drive setup with a drive failure.

I like the idea of what IMCO is doing, eliminating the propellor torque, and balancing the torque is a good idea. The second drive also shares horsepower load, for example a singledrive setup may have a blower motor with 800 propshaft hp, with the dual drive each drive is now sharing the 800 hp (in theory 400 prop shaft hp per drive). I have never seen this application in person, as hopefully someone can give us an update on their experinence with this setup in a pleasure boat scenario.

A few months ago someone posted a few photo's of Randy Davis' ski race boat with this set up: Paul Pfaff turbo motor, IMCO splitter and two IMCO/Bravo drives. If I remember correctly, the boat pulled the winning skiers at both the Nationals and Worlds Ski Races. Its a sure way of getting 1,000+ hp to the water without tearing up your drives every run. Its a perfect set up for hi hp/torque applications where two drives are preferred for speed, handling, docking and longevity...

Does anybody know how much power loss there is with this unit? How many throttles would there be? If there are two for forward & reverse, which would control the rpms? I tried to find it on Imco's pathetic web site, but there is no mention of it. What a great concept though, you save money on the extra engine, but have the prop hook-up and reliability of two drives.

There are a LOT of drag boats running single engine, twin props. they are the fastest drag boats on the planet and have no torque steer.

This could really be a good thing for smaller boats with a big horsepower single engine. It would avoid torque steer and make docking much easier. Those would be advantages. In terms of cost, the idea is to be able to keep running Bravos reliably with 700+ hp without having to shell out for a Speedmaster. But in my opinion, there would be no big savings, if any. Because two Bravos+splitter would have to be significantly less than a single Speedmaster. I don't think this will happen. In terms of performance, the idea is to avoid high power loss associated with the Speedmaster. But again, frictional loss of efficiency of two Bravos+splitter would have to be significantly lower than that of a single Speedmaster, which is going to be difficult. And I say it would have to be significantly lower in order to compensate for the effects of a more diffused thrust of two outdrives vs. one Speedmaster. So I actually think that an inverse splitter would be more useful because it would allow larger boats with 3 or 4 engines to run only two drives which would eliminate torque steer on triples and be good for performance because a) the thrust would be more concentric and b) if the splitter costs less power in terms of friction, then with the addition of one or two splitters and the elimination of one and two drives respectively, the overall loss of power due to inefficiencies in transmission would be reduced ie. more power to the prop... what do y'all think?

how would it be to have a race boat with two motors driving a single shaft drive through a system which is inverse from what IMCO are doing? I know it has been tried. Anybody knows how it affects performance? I have a feeling that it would hurt immediate acceleration but improve top speed and handling. Any ideas?

This boat looks even more wicked in person...

http://www.highperformancecars.com/h...re_028-med.jpg

Seems to me it would be slower due to more hardware dragging in the water.

We made an Arneson Drive back in the late 70's that took two engine to one drive and one engine to two drives.

I do not know where the boat is or how it performed but I still have the prints and such of the project.

Burtandnancy could probably answer better than I...

...but I think the purpose of the dual drive is stability and reliability. For speed skiing, you want the boat fast and smooth...and that's not easy when you're putting 1,100HP+ in a 21'-24' boat. I think they have all the speed they need.

Those boats (w/turbos) can run very fast for a long time.

I have seen Prime Time !!!!!!!!!! WOW those drag boat guys have been using splitters for some time now. Bad ASS!!!!!!!!!!!!!!!:eek:

Team Scarab Had or has a Splitter
Box which we installed in a number
of boats a few years ago (Twin Drive Propulsion systems) US Patent 5649844 hydra-drive systems 764 newton way, costa mesa ca.
Not sure whats up with them right
now ButI know there were a number
of them made.
Mike J.