How does a 16 run with a jet drive?

[Dredgeking]

I'm bored and just throwing out ideas. Has anyone swapped the old Volvo for a jet drive? Did Donzi make 16 with a jet drive? If so, how did the boat run as a jet?

[boxy]

Donzi made some early 18's with jet drives, not to sure about the 16's.

I've always thought the new Merc 240 HP jet drive would be a nice package in a 16.

http://www.mercurymarine.com/mercury_240_efi_jet_drive

[Last Tango]

I have to admit that I have looked at this exact same combo for quite some time (Classic 16 with the 240EFI jet drive). I always thought it would be a fun thing to have, particularly around here where Manatees frequent the water. I have posted several times a few years back on an 18 Classic with the jet drive. CrackerJack was nice enough to photoshop a picture for me, with his tongue firmly planted in his cheek.
Look at how light it is compared to the normal setup! The lower weight might actually be an excellent trade-off for the huge efficiency loss. Might still push a Classic 16 well into the 50's and beyond.
Jet Drives have been discussed here ad infinitum. They occurred on many Donzi's I have seen. 18's, 22's, and some of the rarer older boats in that size like the GT's and such.
I have to think that a boat with a very deep V hull would not be the easiest to mount all this up and get consistent flow. But maybe Someone like MOP or George can respond to that.
If you don't get many responses to this thread, drop an added post in February when the fur really starts to fly on topics like this when the Yankees have severe cabin fever.

Hey, Boxy! Those things are small enough and compact enough that you might actually be able to put TWO in the trunk of a Classic 22. 480HP!!!!
Dual controls... Dual Smartcraft displays instead of individual gauges.
Now where did I put my Lotto ticket?

[MOP]

Very interesting subject, just a hunch but I think a 16 would do very well with a jet. May not be real fast but the fun aspect would more then make up for it. With the reduction in weight and no leg leverage the only bad trait (porpoising) the 16 has will be gone. I have some seat time in a jet for both fun and work, worked a summer towing shutes and raised hell afterwards. The boat was a Rayson with an Olds & a Berkley, loved the jetivator used to get ½ bagged and spray the tourists on the docks. Jets are my guess about 10-15% slower then a prop setup but make up for it in just pure fun, sure hope one of you guys make the plunge I doubt like heck that you would regret it!!

Phil

[Just Say N20]

I don't think the 240 Merc Sport Jet would yield "satisfactory performance" in a 16.

I recently repowered a Bayliner Reflexx (14' boat). It had a Sport Jet 90 from the factory, and I replaced the pump assembly and power head with a Mercury Sport Jet 175. (Here is a link to the repower project, if you like reading fairly well documented projects, although not as good as Rootsy has been doing http://realityboatco.com/RBCtalk/viewtopic.php?t=14 ).


The Reflexx is relatively light, and has 19 degrees of deadrise at the transom. So far I have about 35 hours on the engine, which was freshly rebuilt when I installed it. It is spinning about 5,100 to 5,200 rpms, and a couple of week ends ago Bald Eagle clocked me at 54 GPS mph running along side in his Donzi AE 22.

However, my nephew's 1979 Glastron CVX-16, with a 1979 Evinrude V4 115 hp engine with no nose cones, transom jacks, or any other speed stuff, will still beat the Reflexx out of the hole, and runs almost exactly the same speed at WOT.

Sugar Sands makes some jets using the different Merc Jets, and interestingly, there isn't that much difference between WOT of the 175 (about 53 mph) and the 240 (about 57.8 mph) in the same boat.

My experience with these power packages leads me to predict that the additional weight of a Sweet 16 (compared to the 14' Reflexx), and the 24 degree transom deadrise, would make the boat kind of slow out of the hole, and probably run 50 - 52 @ WOT.

http://i26.photobucket.com/albums/c111/streb2005/SugarSandsStatistics.jpg

http://i26.photobucket.com/albums/c111/streb2005/ReflexxPortquarter-1.jpg

[Last Tango]

Interesting Bayliner. My very first "power boat" was a Regal Rush XP jet boat with the 140HP motor. I have also within this millenium had in my stable of boats at one time a new Bayliner 2855 Ciera (PULLLEEEZE don't mention this to the SEADOGs).
But, the question I am posing now is (and this may actually semi-hijack the thread) is at what point of confinguration and size does a jet boat stop being a "big jet ski" and all those rules, and transform into a "power boat" with the rules that apply to those. Your Bayliner appears to have transended from PWC to BOAT. And then it begs the question that if one builds a Classic 16 with Jet Drive, which is it now? A Classic 16 weighs twice as much as those Tango's, but then a SEADOO 22 weighs about the same.

[yeller]

I've had a 16C with the Berkely 12JC jet on it for 18yrs. I admit it's not a real Donzi. There are a few molds of the 16 kicking around here and my friends dad had a set. Made the boat in 88 and still have it. The jet works awesome on the 16. A 300hp 350, 'A' impeller will get you 63~64mph at sea level. A 'B' impeller will net you 4~5mph more. An American Turbine jet would probably add a couple mph. As well, I'm positive a place divertor would also add 3~5mph as without it, the boat does run a touch bow heavy.
I run the 'A' impeller because the rpms are lower for the same mph and the fuel economy is WAY better. My boat is more than likely heavier than a real 16 too because I wanted it extra strong.
Handling is great. I have no tabs/trim and there is no porpoise or chine walk. I've done tons of full throttle...crank the wheel hard... 180's. Boat will just dig in, change directions and blast off the other way. Also broke a few seats that way. :biggrin.:
Acceleration is hard and quick. It pulls skiers out of the water nearly as quick as my buddies Malibu Skier.

The best thing about the jet drive. I live in an area of logging. Lots of deadheads to watch out for. I've hit several...and just keep on going. :yes:

A few of the busted jet drive myths:
1) Jet drives are terrible on fuel. Not so. I get as good economy as an outdrive.
2) Jet drive boats spin out easily. Not so in a deep V boat.
3) Jet drives are horribly inefficient. Not so. If I put on a place divertor, I'd be in the mid to upper 60's @ 300hp.

[vrod02]

Been around jets for along time. with the 240 package on a 16 approx 35-40 mph would be my guess.Remember this is a outboard/inboard setup. Meaning the 240 started as a outboard motor!20-30% loss."outboard" Jets are weight critical, and thats what this would be.Whats the dead rise on the 16? The bad boy alum shallow v's setups here with 350 blown are only 65-70 mph and there setup for " Small B, Big Block Torg. INBOARD's only". Jets only. As far as the myths theres no way in hell your going to get the same fuel effiency as a prop period.Shallow v hulls spin out worse. Its part of the chartaristics of a jet setup, there made with shallow v's to run shallow and get less wetted surface.. Also you can not "prop" a outboard jet by switching impellers! You can go to a stainless and that about it.

Good info and my source.
http://www.fish.state.pa.us/boatcrs/jet/jetboard.htm

[Just Say N20]

Yeller, good info, and I don't see it contradicting anything regarding the 240 Sport Jet idea. A V8 has a tremendous torque advantage over an outboard jet. My 175 is 2.5 liters versus 5.7 liters for a 350. That difference allows you to hook it to a pump that over comes the short comings of the sport jet package on a heavier boat, or one that has a deep V.

I would love to see some pictures of your boat (as in "How did you do that?"), as a SBC is a tight fit in a 16 when mated to an outdrive. The jet drive combination is even longer. How did you fit it all together? After having had 2 Classic 18s with stern drives (Volvo 270 & Merc Alpha), I have always thought it would be cool to have an 18 or 16 with a jet. I posted a picture in the SHOW ME YOUR ROOSTER thread of an 18 jet. Looks GREAT! :cool:

[BigGrizzly]

There is a jet Donzi that runs the lake george ot the dust off every year it seeems neat

[boxy]

Just Say N20, the pic you posted is the boat Big Grizzly is talking about. That's Barry McLaughin's sweet 18 "Hard Candy". He's from Ottawa, and has also been to the 1000 Islands Run a couple of times.

[Just Say N20]

Boxy, I thought I remembered that 18 Jet as being from the Lake George area. I think I have a few other pictures of the boat sitting at a dock. I really like that boat. Both my 18s were white/baby (Carolina) blue.

Thanks for the info. :)

[yeller]

I don't know anything about the 240 package so I can't comment. All I know is what I've run and based on my experience the jet isn't too far off from running with the I/O setup. What's the top speed of a 300hp 16C outdrive be?? The speed I posted was gps and I stand by the comment that a place divertor would get me a few more mph.

JS N2O...There is more room than you'd think, but that's mostly because I have 'log' style manifolds on mine. I have seen a 16C/350 with center rise manifolds and yes, it is tight. I believe the engine sits lower with a jet drive which helps with access. For reference, the valve covers are about 3" higher than the base of the back seat.
I screwed up when I bought the jet. There are jets where most of the drive sits aft of the transom, but I was a newbie and purchased the standard style which pushed my motor ahead substantially. I had to cut into the base of the back seat a bit to allow for clearance. The intrusion is barely noticable from an interior view though.

I don't have the boat here so I can't take any pics right now. I kicked it out for the new 22' blonde in my life. :biggrin.: The 22 is a blast and way more comfortable, but it isn't anywhere near as much FUN as the 16. I wish we had a longer boating season so I could justify keeping it.

[boxy]

Boxy, I thought I remembered that 18 Jet as being from the Lake George area. I think I have a few other pictures of the boat sitting at a dock. I really like that boat. Both my 18s were white/baby (Carolina) blue.
Thanks for the info. :)

Barry has made the trip to Lake George numerous times, it's a short tow from here ..... :D

[Uncle Fester]

Yeller....got several shots of you in the 16 from Chelan in '05 in my gallery.

http://www.donzi.net/photopost/data/572/medium/3734DSCN0918.jpg