This thing is nuts do it yourself.

Got to ask, what is your day job?

Not sure if I’m more impressed by the work being done diy or the amount of time he has. Especially with young child. Maybe never sleeps?

Keep on it!

I have own company, Voltek Oy, repair truck, bus, construction equipment and boat engines, transmissions, powertrain, electrics and all kind of works. I don't have employees, I do all myself. Time is little short nowadays. A usually always 2-6 weeks queue in work order book.

Transmission part 3, this goes more complicated...


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Front end is assembled, spline sleeve and front plate in place, right dimension shaft seal was plug and play, 5mm smaller inner diameter than original.

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Cut down back end waiting for splitbox, there is narrow constant sealing surface that will keep transmission oil inside.

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Soft gasket help sealing if dimesions are little off or things move under power.

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Splitbox inner plate in place. Blue shaft seal separate transmission oil and splitbox oil.

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Exact lengh spacers keep splitbox in right place, I bolt every bolt through splitbox as possible, there should be 10.000Nm torque some day in this joint.

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Middle section, it's centered by four 10mm cylindrical pin and have O-ring groove for sealing.

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Luckily I found out that transmission back bearing have to get some lubrication, Spacer sleeve between transmission and splitbox gear have to had lubrication route to bearing. Now it should work, oil come from last planetary shaft hole inside sleeve and then goes to bearing via two holes.

I still find it very odd that no one has done this yet. I'm not sure the timing is right if a barrel of oil drops like they think is going to happen soon.

Transmission part 4.

I try make this boat as reliable I can. Splitbox spur gears are not best material available, they are C45, medium carbon steel. Center gear is nitrided, others are induction hardened. I deside to coat them with Tech Line coatings TMLM https://techlinecoatings.com/new-int...gine-coatings/
But first I need an owen that can be heated to 150C degree.

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I build it from scratch that was surplus stuff from house building, and some other used parts, cost about 20€, ugly but did it job.
Parts have to degrease very carefully and sandblast with alumium oxide that is expensive. So next I have to build sandblast place with recycling, I don't want to waste expensive stuff. It's actually more ugly than owen but work also great! Vacuum cleaner take dust off and heavier particles goes down to bucket and then in use again.

Does anyone here try coating to boat parts? In finland some people have coat race car differential gears with succeed, could work on weak bravo 1 gears too.
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Test heat outside of buildinf if it get fire. I think it would complies with all regulations:rolleyes:

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Ikea 10€ rotating tray was very helpful for sandblasting and coating to get nice even blast and coat.


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This is very scary blast rough surface to gear tooth surfaces, but job was easy and fast.

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Recycling system work pretty good and waste was only 10%


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I grind all teeth edges to smooth so there should not be any stress points that can tear tooth off.

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Lot of work to make all of them....

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Coatings fried 150C at one hour after parts are heated to 150C, I had K type thermometer to see right temp, owen have old stove thermostat to keep constant temp. I coat cam followers too, 48 pieces with stiff springs make some friction. I will measure engine turning torque after assembly without compression, it will be nice to compare BBC friction. I dont remember how much for example HP525 rotating torque are, I had two of them in my 29' outlaw. Does anyone know?

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Coat change color little after owen session. I really want to believe this make differrence to efficiency and wear, too much work for failure.

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Assembled and shimmed splitbox! Next thing is machine oil level sight, fill and breather threads to end plate. then measure and adjust rest bearings axial play. Thing go forward fast now

Around 500 ft lbs torque for the HP 500 and same for 525 EFI

I believe there was people in the offroad world cyro treating ring and pinion differential gears. Seemed that it did help, but not enough to make the time and effort worth it.

Been enjoying this thread since the beginning and every time I catch up on it I'm blown away!

Thanks for sharing your amazing project, and keeping Custom Offshore Powerboating alive!

I just wish I could accomplish 10% of what you do on my projects lol!

For torque of efi 525 look there at #6. It is for efi 500 and I would add 5% for 525.
https://www.offshoreonly.com/forums/...yno-sheet.html

You have a lot of gear pairs from engine to the props. What losses do you expect there? (Usually for good gear pair come 0,98%, the same for bearings, it mean 4-5% for one pair.)