Haven't even started my first build yet......

About using jet ski motors to power small boats

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DSR
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Haven't even started my first build yet......

Postby DSR » Fri Oct 28, 2016 8:33 pm

I haven't even cut my first piece of lumber for the TNT and I think I already know what I want to do for the next build (yeah, I caught the boat-building bug..... :roll: )

I have a 6.0L LS engine and a powerglide sitting here in the shop waiting patiently for a Tornado to climb into (that was slated to be the build after the jet) but I was trolling through the forum, stumbled upon Carmine's "gentlemen's racer" Zip, and fell in love!!

20150718_160443.jpg


Please tell me if this sounds stupid, but as soon as I saw this beautifully built Zip, I immediately thought "what would happen if I built something like this with a newer 4-stroke 4-cylinder ski powertrain like myTNT but with the engine divorced from the pump and mounted ahead of the cockpit like a true gentleman's racer with a driveshaft back to the pump at the transom?"

Does this sound like a crazy idea to anyone else?

Dave
DSR Performance - Home of yet another jet TNT build :D
Codename "Just A Little....."
viewtopic.php?f=23&t=29753

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Dave Grason
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Re: Haven't even started my first build yet......

Postby Dave Grason » Sat Oct 29, 2016 2:23 am

DSR wrote: Does this sound like a crazy idea to anyone else?


Innovative yes. Crazy? No.

The first rule on this forum AND among virtually all Glen-L builders is that this is YOUR boat and you get to do whatever you want with it. No one here will judge you. We are a community of independent and critical thinkers. We will warn you if we something dangerous coming up, or even some random mistake that will cost you precious time and money, but that's not the same as judging you.

I personally think that your idea is excellent! Give us some more details.
Isn't it amazing!! The person that never has the fortitude to pursue his own dreams, will be the first to try and discourage you from pursuing yours.

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chugalug
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Re: Haven't even started my first build yet......

Postby chugalug » Sat Oct 29, 2016 8:00 am

:D Nothing wrong about thinking of second builds.I'm already thinking about my second build even tho I'm not quite done with "Chug".My problem is I'll have to add 10 ft onto a 24ft. shed first. :D
Working on regular-sized Bo-Jest


"If it's not crooked,It's not mine

DSR
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Re: Haven't even started my first build yet......

Postby DSR » Sat Oct 29, 2016 9:56 am

Hi Dave and Chug, I appreciate that. Thank you.

Now, mind you, this is all just my personal opinion.
Looking at Carmine's interpretation of the Zip, it's aesthetically almost perfect in my eyes. The boat in this picture looks like it's going 100 mph just sitting on that trailer, but it's doing it with a very elegant '30s retro feel to it (if that makes any sense).
But, looking at this boat, I'm having a really hard time imagining it with an outboard mounted to the back of it. In my mind, it just wouldn't look"right" to me (and again, that's just my personal opinion).
So I thought, since I've started messing with the Honda jet ski that I obtained for the TNT, that it would work really well to power a Zip built as a gentleman's racer as soon as I saw this boat.
I can see stretching it the 10%, put the cockpit in the same position as Carmines, and "tunnel" the jet pump into the back of the hull (similar to the mounting on the skis) to make the pump as unobtrusive looking as possible. Taking my Honda R12X engine, as an example. It's a small package (33" long including the turbo by 16" wide and short enough to fit under a flush deck hatch with a lot of room to spare on the Zip), already marinized, pretty darn light for a 4-cylinder at 220 lbs complete and bone-stock makes 165hp, which pushes the 842 lb ski to 62-64 mph. It should move a Zip out pretty well I would think (and as a bonus, it sounds like an automotive engine, being a 4-stroke).. Fabbing a driveshaft (with a polished stainless driveline guard of course) and exhaust would be very doable. Mounted on full-length stringers.
Courtesy of my TNT project, the pump would be modified with a cast intake housing to become a one-piece bolt-in assembly to replace the fiberglass hull intake and would weigh less than 40 lbs. Also courtesy of the TNT, I've been working with my father (himself being a retired engineer) and we think we've come up with a very effective solution for keeping the pump loaded at higher speeds with the low deadrise "warped" bottom design these boats have....... but I haven't really put much thought into it.......
.....Whew! :roll:

If you haven't noticed yet, I have been known to ramble when I get stuck on something.....

Thanks for putting up with me!

Dave
DSR Performance - Home of yet another jet TNT build :D
Codename "Just A Little....."
viewtopic.php?f=23&t=29753

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hoodman
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Re: Haven't even started my first build yet......

Postby hoodman » Sat Oct 29, 2016 4:35 pm

Cool man, I'd be interested to see this come together. A whole new way to power a boat with a lightweight inboard.

DSR
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Re: Haven't even started my first build yet......

Postby DSR » Sun Oct 30, 2016 7:12 am

Hi Matt, thanks for stopping by.

The more I look at pictures of Carmine's Zip and think about it, the more seriously I'm considering shelving the TNT project and building this thing first. I don't know how innovative or new this idea is but I haven't run across anybody here or out on the net that's done this style of setup on a Zip yet.
I haven't really considered building a Zip before and I'm definitely going to have to do more research on it before I jump into it. This setup would change the CG of the boat pretty drastically, but from what I've been reading that may not necessarily be a bad thing with this design. It seems that the Zip has a tendency to porpoise under way and it looks like with people running heavier outboards it tends to get worse. There's no way to know if moving the CG forward this much would cure the problem without testing of course, but I'd bet that it would help a lot. The other issues that I can see with doing this would be
1) with the Zip being a hard chine hull and dealing with the way jet-driven boats handle with "sliding" in turns under power, and 2) the safe speed limits of the design. I'm thinking that the handling aspect would be just a learning curve with a big dose of common sense, but with the very real possibility of building this with the TNT's Honda setup I have, I could end up with a boat 100 lbs lighter than the ski, and with a more efficient hull with low deadrise, this thing could be capable of 65-70 mph. Will this design handle those kinds of speeds "safely" or predictably?
Any thoughts on these issues from anyone here would be greatly appreciated.

Thanks
Dave
DSR Performance - Home of yet another jet TNT build :D
Codename "Just A Little....."
viewtopic.php?f=23&t=29753

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Bill Edmundson
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Re: Haven't even started my first build yet......

Postby Bill Edmundson » Sun Oct 30, 2016 7:34 am

Dave

Why not just do a Cracker Box? It's designed for inboard and 70 MPH.

Bill
Mini -Tug, KH Tahoe 19 & Bartender 24 - There can be no miracle recoveries without first screwing up.
Tahoe 19 Build

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chugalug
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Re: Haven't even started my first build yet......

Postby chugalug » Sun Oct 30, 2016 8:05 am

:D Or Down-sized Gentry? :roll: :roll:
Working on regular-sized Bo-Jest


"If it's not crooked,It's not mine

DSR
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Re: Haven't even started my first build yet......

Postby DSR » Sun Oct 30, 2016 9:12 am

Hi Bill and Chug.
You know, I've looked at the Crackerbox and the Gentry several times and I can't really put my finger on it, but they never really "flipped the switch" and captured my attention like Carmine's Zip has. It's the same thing with the other Zips I've looked at also. They're all beautiful designs for sure, and the people that crafted these designs have done wonderful works of floating art with them, but they never really stopped me in my tracks like this Zip has.
I wish I could tell you exactly what it is about this boat that caused it but I can't. Maybe it's just a specific combination of elements that are incorporated into his build that did it. It's kinda like going to a car show and seeing two really nice '55 Chevys sitting side by side. One is red with chrome wheels and looks great but the one next to it is white with a different style wheels and grabs your attention like the red one could never do. Same cars, but two completely different reactions. I don't know if that makes any sense or if I'm the only one to experience this, but that's what happened :lol:

Thanks
Dave
DSR Performance - Home of yet another jet TNT build :D
Codename "Just A Little....."
viewtopic.php?f=23&t=29753

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Bill Edmundson
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Re: Haven't even started my first build yet......

Postby Bill Edmundson » Sun Oct 30, 2016 10:21 am

Dave

Makes sense. Sometimes there is just that one that your eye just keeps coming back to.

Bill
Mini -Tug, KH Tahoe 19 & Bartender 24 - There can be no miracle recoveries without first screwing up.
Tahoe 19 Build

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hoodman
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Re: Haven't even started my first build yet......

Postby hoodman » Sun Oct 30, 2016 4:51 pm

65 in a zip? I'll take video from the dock while you fly by.

DSR
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Re: Haven't even started my first build yet......

Postby DSR » Sun Oct 30, 2016 5:24 pm

It might be doing exactly that too Matt :lol:
DSR Performance - Home of yet another jet TNT build :D
Codename "Just A Little....."
viewtopic.php?f=23&t=29753

DSR
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Re: Haven't even started my first build yet......

Postby DSR » Wed Nov 02, 2016 5:33 pm

Hi everyone,

Well, FWIW, I decided to continue with the TNT build.
Buuuuut....... while all that's going on, I'm gonna start shopping for another wrecked 4-stroke 4 cylinder jet ski because I also decided that I need to do a jet Zip after I get done with the TNT :D

How's it going to work?

Like I always say " only one way to find out....."

......... or is it " here, hold my beer, I wanna try something......"?....

Thanks again for all your help!!!!
Dave
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DSR Performance - Home of yet another jet TNT build :D
Codename "Just A Little....."
viewtopic.php?f=23&t=29753

JimmY
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Re: Haven't even started my first build yet......

Postby JimmY » Sat Nov 05, 2016 5:42 pm

If you've ever lost a relative after they said "hey everyone, watch this."...

Nice drawing.
-Jim
Nothing says poor craftsmanship like wrinkles in your duct tape!

DSR
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Re: Haven't even started my first build yet......

Postby DSR » Sat Nov 05, 2016 6:03 pm

:lol: :lol: :lol: :lol: ............. nope.

.........at least, not yet...........

........that I know of........

And us Michiganders are not rednecks....... we're Cedar Savages.......

I'm also going to blame my 9 year old for the drawing.
I was sitting at the table a few nights ago helping her with homework and the paper and pencil were sitting right there next to me..... :D

Thanks Jim!
DSR Performance - Home of yet another jet TNT build :D
Codename "Just A Little....."
viewtopic.php?f=23&t=29753


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