Typically, you see a dual jet setup (rare) in a much larger boat in the 24' up range with twin engines, spaced much further apart apart than that just like a twin outdrive setups you see on offshore boats and these ultra-rich Desert Storm floats. There's been a few cats set 'em up in much smaller boats. One of them in Texas actually used twin 460's in an 18' Baja or Taylor or something using the special Berk right and left intakes and normal hookups we're used to seeing, just two of 'em. As I recall, that particular boat was plagued with all sorts of handling and mechanical problems though. Probably had a lot to do with another 900 lb Big Block in a teeny boat and the jets being spaced much further apart (as they are in the big boat installs) where cavitation also has to be an issue.
The special twin intakes, these are still available from Berkeley, BTW, a grand apeice. Those loaders were custom made by our own MadSkilllz here o the boards.
The boat in the Youtube video obviously cut up a pair of these and welded them back together to move the drives as close together as possible. Another one of them I saw pictures of had a completely custom intake with one huge bottom opening coming to to 2 jet drive flanges. Don't know about the boat in your CL ad, but probably similar to the one on Youtube and that gear/chain box used to drive them from a single engine I've seen before on most of these. Not sure who makes it, but sure it's a pretty custom (expensive) piece. There's also other things to consider, like special helms to operate two steering cables, special forward/reverse levers (or 2 of them) and cables, twin diverter set-ups, etc.
Personally, I can see where the one on Youtube could actually drive 2 12JG jets pretty effectively with an advertised 1000HP, and even with the lost parasitic power through that gear/chain box with a pair of A impellers. On the one in your CL ad though, I'm at a loss to understand any advantage. That engine appears to be nowhere near 1000HP (probably more in the 500-600HP range, and I don't see the justification that he feels it's worth $8500 by itself). The parasitic loss through that gear/chain box, coupled with the additional loss just turning another jet, add in the additional weight of the whole apparatus would drop the efficiency so much that a std 320HP +/- single jet in the same boat would probably smoke it.
I suppose you could play with different impellers and gear reduction possibilities (say, being able to spin the jets @5000 RPM while the motor chugs along @3500 RPM) but I don't see the HP in that one to make that a viable arguement.
It is cool though! Funtionality eludes me, however, other than bench racing ownage.
Ray
