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Matty B

Ea81 jet boat its on!

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Years of planning and scribbling on beer coasters have come together!

Requirements:

Shallow draught (less than 4 inches planing) 14 foot hull,

 

motorcycle steering with thumb throttle (ala 4 wheeler)

 

Subie power connected to a single stage waterjet unit similar to this-

 

http://www.aquajet.co.nz/unit.htm.

 

But being the purist backyarder, and the fact that I love to MAKE much more than SPEND I have had the win of all wins!

 

An old mate of my Dads has just let me know of an old jet boat project he will pass on to me if I want, he hasn't touched it for 14 years and it is dry and safe in the back of a farm shed.

 

He has built a 16 foot plywood punt to save his sheep when it floods, and was planning to bolt up this Hamilton jet unit and a holden 179 to it.

 

I will fit the jet to the hull temorarily for the summer while I get a local firm to make me a new custom polythene hull.

They make heaps of them in Tassie for the salmon farmers and even the Cops have a couple, they are indestructable.

 

http://www.plasticfab.com.au/flash/blank.htm

Run them over rocks, sand, hell break them (if you can) and the pieces float.

 

And of course there will be blurring pushrods.

The mark 1 Wonder Brumby motor is being hybridized into the power plant.

EA81, heaps of Kms on it, weber, wet exhaust (ally irrigation pipe with injection).

I am fitting 82T pistons and the turbo with weber if I can water cool the down pipe and jacket the rest.

No rules on the water,

No speed cameras, icon_twisted.gif

no rego permits,

No illegal mods regulations,

No one will be going through water as shallow as me!

icon_eek.gif

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Sounds awsome:banana:

 

About a month ago I was looking at a friends speedboat which had a 351 in it, it was huge, and i thought why couldnt you do it on a smaller scale with a sube motor:D

 

I assume that u r gonna use water to intercool the turbo'd air

Do you have to treat the waterjacket in the engine to protect it from the salt?

How much power are you expecting gain from it?

 

Good luck

 

P.S. i hope to see some pictures of construction

 

GO GO AUSSIE INOVATION!!!:brow:

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I am fitting 82T pistons and the turbo with weber if I can water cool the down pipe and jacket the rest.

The performance method is to use EA81T pistons, they are slightly higher compression then the EA82T pistons. Many many years ago, I work with a boat maker who used Berkley jet drives, at the time these were pretty much unknown, but they sure worked great. The one downside was they required more power to make them work like the prop driven boats, the plus was we never worried about shallows.

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Do you have to treat the waterjacket in the engine to protect it from the salt?

Freshwater cooling would be the best alternative. Probably on a jetboat you could just run water to a water-to-water heat exchanger from the jet drive itself, rather than having cooling coils on the bottom of the hull that could get damaged in shallow water.

 

I saw pics of an n/a EJ20 in a jetboat once, but I think this sounds cooler!

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Try this.

http://www.aquajet.co.nz/home.htm

 

No intercooler plans atm, simple as possible.

No electronics either.

pushrods,

carb,

light and indestructable.

We are planning some big upriver trips and want to be able to hand winch it up and over the rough stuff (waterfalls etc).

The Wonder Brumby has to be able to tow it as well.

BTW a holden 179 is an old GM straight six (not a bad one either, just too tall, long and made of the wrong metal). circa 1963-1967.

I have a busy summer planned now!

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The performance method is to use EA81T pistons, they are slightly higher compression then the EA82T pistons. Many many years ago, I work with a boat maker who used Berkley jet drives, at the time these were pretty much unknown, but they sure worked great. The one downside was they required more power to make them work like the prop driven boats, the plus was we never worried about shallows.

G'day Doc, the Berkley and Hamilton drives are very similar, they do drop a fair bit of efficiency compared to some of the newer nozzle designs.

What the hell - I will feed it more fuel and compress it!

I am prepared to be flexable with the first protype, we will set a HP figure that is obtainable all day, every day, in all condiotions, with total reliability (SUBARU RELIABILITY).

We think 90 horsepower is achievable at the spot where the flywheel would normally be.

Then adjust the impellor pitch to suit load and speed requirements for the new hull later.

 

210 kg hull weight

minimum payload 480 kg

200kg for EA81, jet, shaft, steering, winch,

150 kg for two average sized blokes

80 kg (80 litres) fuel (lots)

40 kg Fishing gear, at least one dog, beer, swags etc

 

Should come in at under 700 kg, wet!

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