Bruce Crandall Flyer Hydroplane

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Fuzz
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Re: Bruce Crandall Flyer Hydroplane

Post by Fuzz » Mon Jan 22, 2018 5:39 pm

Peter I am no motor head but I am pretty sure the damper plate does what it sounds like. That is dampen the shock when you engage a turning engine to a stationary transmission. Sort of like dropping the clutch or easing it out. Maybe one of our gear heads with chime in with better answers.



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Re: Bruce Crandall Flyer Hydroplane

Post by jacquesmm » Mon Jan 22, 2018 5:41 pm

The damper plate absorbs the shock when you change gear. Look at it closely (or google damper plate) and you will see that the spline is fastened to the plate by big springs. The springs absorb the torque of the engine.
Even if you go for the Harley engine, you need a damper plate. If you don;t have it, each gear change will shake the crankshaft and you will quickly have ugly oil leaks at the main bearings.

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Re: Bruce Crandall Flyer Hydroplane

Post by glossieblack » Mon Jan 22, 2018 6:56 pm

Peter, I don't think it's possible to mate up a bellhousing based marine gear box with a Harley engine without significant re-enginnering.

I believe the 1:1 box bellow would be practical, and would be way lighter than a Velvet Drive or ZF Hurth.

You would need the following sequence, working forward from the prop.

Prop shaft passing through cutlass bearing then connecting to a thrust bearing assembly anchored to hull then connecting to the aft end of the box, then a second shaft connecting the forward end of the box to the Harley engine.

The thrust bearing anchored to the hull is essential, without it the gearbox and the engine will be destroyed.

Edit: Marine gearboxes have a thrust bearing built in. The box below doesn't, hence the need to one between it and the prop.

[youtube]https://www.youtube.com/watch?v=mBkN3CdBtOU[/youtube]
Last edited by glossieblack on Mon Jan 22, 2018 10:02 pm, edited 2 times in total.
Currently building Jacques Mertens ST21 "Skinnydip". Boating adventures: Splash testing and using 'Skinnydip, as a basis of further building refinement; Adams 44’ sailing sloop "Great Sandy" (cruising and maintaining); Iain Oughtred Feather Pram "Mini Dip" (building); Jacques Mertens R13 "Wood Duck" (built and due for maintenance).

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Re: Bruce Crandall Flyer Hydroplane

Post by OrangeQuest » Mon Jan 22, 2018 7:56 pm

Fuzz wrote:
Mon Jan 22, 2018 5:39 pm
Peter I am no motor head but I am pretty sure the damper plate does what it sounds like. That is dampen the shock when you engage a turning engine to a stationary transmission. Sort of like dropping the clutch or easing it out. Maybe one of our gear heads with chime in with better answers.
I am no marine gear head but the damper plate looks like a flywheel and clutch disc in one unit on a standard transmission, without a pressure plate to engage/disengage the engine from trans. Just like others have said it absorbs the pulses of the engine and the shock of putting the trans in gear.
The input shaft of the transmission slides into the center of the damper plate but is not bolted directly to it. The trans bolts to the bellhousing then the bellhousing bolts to the block of the engine. The bell housing sets the depth the input shaft goes into the damper plate and where the starter engages the ring gear that is on the flywheel.

With the damper plate and trans bolt patterns being the same a lot of power units can be used with the same trans. As long as it is a marine power unit.

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Re: Bruce Crandall Flyer Hydroplane

Post by deuce_454 » Tue Jan 23, 2018 4:47 pm

if you pay the shipping you can have my gray marine 180 hp (buick aluminium v8) with heat exchanger, carb, starter, water-cooled exhaust bell housing and a 1:1 velvet drive for less than 2 grand .. it will need hoses and TLC, but its a light weight v8 that will be perfect for your project.. ill even throw it in a crate (but its located in europe, so you will need to be creative with the shipping)

i won't get around to using it (i was going to put in a ja18 but that project stalled)... i also have a hamilton jet i can throw in if you were so inclined

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Re: Bruce Crandall Flyer Hydroplane

Post by deuce_454 » Tue Jan 23, 2018 4:49 pm

hell you can have the whole mess for 1600

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Re: Bruce Crandall Flyer Hydroplane

Post by peter-curacao » Wed Jan 24, 2018 9:52 pm

deuce_454 wrote:
Tue Jan 23, 2018 4:47 pm
if you pay the shipping you can have my gray marine 180 hp (buick aluminium v8) with heat exchanger, carb, starter, water-cooled exhaust bell housing and a 1:1 velvet drive for less than 2 grand .. it will need hoses and TLC, but its a light weight v8 that will be perfect for your project.. ill even throw it in a crate (but its located in europe, so you will need to be creative with the shipping)

i won't get around to using it (i was going to put in a ja18 but that project stalled)... i also have a hamilton jet i can throw in if you were so inclined
deuce_454 wrote:
Tue Jan 23, 2018 4:49 pm
hell you can have the whole mess for 1600
Very interested I will contact you by pb if that's okay?

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Re: Bruce Crandall Flyer Hydroplane

Post by jacquesmm » Thu Jan 25, 2018 10:45 am

That sounds like a great deal. Make certain that it fits but I have the feeling that it will.
The good part is that it is a complete set with transmission and a 1:1 gear, perfect.
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Re: Bruce Crandall Flyer Hydroplane

Post by peter-curacao » Thu Jan 25, 2018 12:16 pm

jacquesmm wrote:
Thu Jan 25, 2018 10:45 am
That sounds like a great deal. Make certain that it fits but I have the feeling that it will.
The good part is that it is a complete set with transmission and a 1:1 gear, perfect.
Yes I do think so also, just have to see what the shipping costs are, even hoping I can make the jet work in the last transom step, I asked and awaiting for pictures and measurements so hopefully I know it soon, as soon as I know I give an update 8)

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Re: Bruce Crandall Flyer Hydroplane

Post by pee wee » Thu Jan 25, 2018 1:17 pm

Peter, it's so good to see this build moving along- I'm one of a crowd hoping to see this thing get splashed one day!

The way you work around problems and find solutions is an inspiration to me. Working from the kind of plans you are working with is no picnic, I'm sure, but it does encourage innovation, and once successfully completed you will have something special. Can't wait to see what comes next.
Hank

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