Is this why Albatross Alpines ruin their engines?

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Tatra Man
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Joined: Mon Jul 19, 2010 12:11 pm
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Is this why Albatross Alpines ruin their engines?

Post by Tatra Man »

With one known exception, Albatross Alpines never have their original engines and some owners have changed the engine several times while others have gone over to Ford engines. This puzzles me because the hours of use of a boat engine are hardly the same as a car and I've had 186,000 miles out of a Sunbeam Alpine without a re-bore or a bearing failure. So why does it happen?

Unlike other Albatrosses, the Alpines have the drive taken from the flywheel end of the engine. There's no clutch, so they're direct drive like all the others and the thrust is supposed to be taken by a bearing in the box between the prop. and the bell-housing. Running through that thrust box is this shaft:-

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The right hand end of the shaft is the end bolted to the crankshaft and which also clamps the flywheel in place and obviously this can only be done before the bell-housing is fitted. The thrust box is bolted to the bell-housing from the inside so that has to be fitted to the bell-housing before the bell-housing is bolted to the block. I would assume that the flange near the left hand end of the shaft bears on a thrust race inside the thrust block and that, when the bell-housing is mated to the engine, the shaft slides into the cast iron bit at the right which is already bolted to the engine. So is what looks like a key-way and two grub screws the only thing that takes the power from the engine? Is it meant to slide in and out like a splined shaft would and, if so, what stops the grub screws from coming undone? If the grub screws are meant to be tightened, are they tightened through the side of the bell-housing and what then stops some of the thrust being transferred to the crankshaft and eventually wrecking the engine's thrust shells and knackering the thrust faces of the crankshaft? Is this why the engines fail?

As a matter of interest, the threads at the left hand end are anti-clockwise. I thought anti-clockwise threads were used where the prop. shaft was clamped on other Albatrosses but this shaft rotates the opposite way so logic tells me the thread should be clockwise.

Does anyone have any answers?
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I hope my new Alpine floats better than my old one!

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Tatra Man
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Joined: Mon Jul 19, 2010 12:11 pm
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Re: Is this why Albatross Alpines ruin their engines?

Post by Tatra Man »

A bit more investigation reveals that the shaft does, indeed, slide backwards and forwards inside the cast iron sleeve and that the entire engine torque appears to be taken by the two allen head grub screws. You can't see it but there are marks in the thrust side of the keyway made by the threads of the grub screws.

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Incredible!!

At the other end of the bronze shaft, the centre of the thrust race is clamped between the flange and the anti-clockwise threaded nut (which I don't yet have) and the outer of the thrust race is clamped into the thrust housing. OK - so looking at it all from the back of the boat, the prop shaft rotates anti-clockwise (unlike other Albatrosses) and is turning the centre of the thrust race which is clamped by an anti-clockwise threaded nut which itself takes all the thrust. Did Albatross make a big boo-boo here because, surely, that nut is going to tend to undo!!? Other Albatrosses have anti-clockwise threads in this area, surely this one should be clockwise? Does this account for all the marks in the keyway which appear to be caused by the grub screws as the shaft moves in and out?

Can someone who's worked on one of these please comment!!?Image
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I hope my new Alpine floats better than my old one!

Jonty
Posts: 9
Joined: Wed Nov 11, 2009 6:33 pm

Re: Is this why Albatross Alpines ruin their engines?

Post by Jonty »

10 year later! Did you get answers or work it out yourself? I can answer all your q's if you still need them.

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