Seeking Information & Assistance

Designs for inboard or outboard power

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kens
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Location: Coastal Georgia

Re: Seeking Information & Assistance

Postby kens » Thu Aug 03, 2017 6:43 pm

yes, you can delete the cabin, I already have,
yes, you can move the helm anywhere you want it
no, dont beef it up, it is already strong enough
yes, it will accept a small block V8

here is a link to mine, with a 3.0L chevy with a velvet drive inboard
https://www.youtube.com/watch?v=inT-vDWh2I8
Oak is over rated, everything about it takes extra time; then it warps, splits or checks !!! :roll:

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kens
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Joined: Wed Nov 12, 2003 5:25 pm
Location: Coastal Georgia

Re: Seeking Information & Assistance

Postby kens » Thu Aug 03, 2017 6:45 pm

here is another Double Eagle, stretched out to 30', with lift strakes, and 350 SBC sterndrive
https://www.youtube.com/watch?v=iuBbExKSKsA
Oak is over rated, everything about it takes extra time; then it warps, splits or checks !!! :roll:

Mr_Big_J
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Joined: Wed Aug 02, 2017 5:36 pm
Location: Western Montana, USA

Re: Seeking Information & Assistance

Postby Mr_Big_J » Thu Aug 03, 2017 7:03 pm

Ken,

Beautiful boat! Thank you for those links.

Jason

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chugalug
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Re: Seeking Information & Assistance

Postby chugalug » Fri Aug 04, 2017 6:12 am

:D Years ago,I used to own a Fibreform fibreglass boat,24 ft. similar to the Bolero.Had v-berth up forward but no cabin (was big open boat) motor box in stern with seating on each side and back-to-backs fold out ones for passengers and driver.Had 302 Ford Mercruiser(188hp) which was sufficient for 1 or 2 people.Had problems getting on plane with 6 people even with 15 inch power prop.Would have been better with a 260.Had soft top and rear enclosure to keep out of weather or on trailer .would have been nice with a camper top.If I wanted another one like it,I would build the Bolero and do the mods similar. :D
Working on regular-sized Bo-Jest


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

Mr_Big_J
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Joined: Wed Aug 02, 2017 5:36 pm
Location: Western Montana, USA

Re: Seeking Information & Assistance

Postby Mr_Big_J » Fri Aug 04, 2017 8:22 pm

chugalug wrote::D Years ago,I used to own a Fibreform fibreglass boat,24 ft. similar to the Bolero.Had v-berth up forward but no cabin (was big open boat) motor box in stern with seating on each side and back-to-backs fold out ones for passengers and driver.Had 302 Ford Mercruiser(188hp) which was sufficient for 1 or 2 people.Had problems getting on plane with 6 people even with 15 inch power prop.Would have been better with a 260.Had soft top and rear enclosure to keep out of weather or on trailer .would have been nice with a camper top.If I wanted another one like it,I would build the Bolero and do the mods similar. :D


Chug,

Interesting suggestion. One of the things holding me back from the Bolero was not having an open bow. If it could be built with an open bow then it is almost the perfect boat for the job. Not sure how difficult the Bolero is to build as opposed to other boats mentioned... Also, what is a 260 as opposed to the 302 Ford? Is it a 6 cylinder?

Jason

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chugalug
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Re: Seeking Information & Assistance

Postby chugalug » Fri Aug 04, 2017 9:45 pm

:D Sorry about that.the 260 is a Mercruiser 5.7 350 cu.in.I/O .the 302 was a v8 also but lacked power with lots of passengers( I used it for guiding years ago)What was nice was even if rough out(4 ft whitecaps on the angle bay)it would cut right through without bouncing.the hull was made pretty good with balsa core and lots of fibreglass
Working on regular-sized Bo-Jest


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

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X23
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Re: Seeking Information & Assistance

Postby X23 » Sun Aug 13, 2017 9:32 am

Glad to have you aboard!

It is a good thing that you are thinking out how you will use the craft, and looking at alternatives. Here are some random thoughts to help your process:

Picture the end of a great day on the water. You are gliding up to the courtesy dock to let off passengers before putting your vessel on the trailer for the ride home. Imagine the soft burble of that V8, the slap of tiny ripples on the cutwater as you wait to use a second of idle in reverse. You move the lever to reverse and hear the hydraulic sound of the prop working under the hull. There was no clunk into gear, no vibration into the hull, it just started working with a tiny reduction in idle rpm as the small load was shouldered by the engine. Out of gear is the same, the hydraulic sound just quits, no clunk - it is velvet smooth. You use additional small idle power as needed and arrive right next to the dock, drop a loop over one of the cleats and put the helm over, using idle forward to nudge the aft end over so a family member can secure that end to the dock. That is the magic of the hydraulically shifted Velvet Drive transmission.

And there is a V-drive version as well, look into their Liberty line. A stern drive is similar in mechanical function to an outboard, where a constantly spinning gear driven by the engine is meshed with a clunk to the motionless prop connected gear. This does not bother lots of folks, but I sure like that Velvet Drive.

If having a motor box farther forward would have you using it as a table or work area, the straight inboard plan would work. Having the engine weight farther forward does permit a heavier powerplant, but that extra weight subtracts from the carrying capacity.

If your 350 is not already a marine engine, you will be changing things to let it assume that role. You will need a marine carburetor with flash arrester, the starter and alternator need to be changed to marine components, and water cooled exhaust manifolds added. That is likely why you already heard the suggestion to look for a marinized engine package.

Someone elsewhere on the forums said that you can change most anything topside on the plans, but don’t change the hull.

All of the plans sets tell you the power required to reach several speeds. Pulling a tube can be fun in the 20s, or more relaxed while barely on plane in the high teens. Or it can be quite adrenalin filled in the 30s, depending on the water conditions. Water skiing is seldom done faster than the mid 30s. Plan to use no more than about 75% power for your intended cruise speed.

Most 4 stroke engines use a bit less than half a pound of gasoline for each horsepower hour, the 2 strokes come in closer to the half a pound number. So figure on burning a gallon of fuel to make 14 HP for an hour with a 4 stroke, and the same gallon will give you 12 HP for an hour in a 2 stroke. If you are planning on using 50-75% of that 350’s capability for hours then you will need a sizable fuel tank (or tanks). If you only need 70 HP from your engine, you will be feeding it about 5 gallons in an hour.

Remember that skiing or tube pulling is not done for hours without stops, and idle on a mid sized V8 like your 350 will be 1.5 gallons per hour or a bit less if fuel injected, which helps a lot on the day’s tally of fuel used.

This weekend I did vessel exams at a NM lake, and two boats in the mid 20 foot range were each using a pair of Yamaha jet drives. So this triggered another thought – you could take jet ski drive systems & use those on your vessel. These are available lightly used from marine salvage yards, because the young operators often drink the beer & do crazy things. Since the engine & pump are in the rear, and the crash damage is on the other end, the totaled vessels often yield usable drive systems.

So let us all know what you are thinking about. Time spent planning your boat & how you will use it is very valuable.

Jack


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