Is this why Albatross Alpines ruin their engines?
Posted: Thu Jun 21, 2012 11:44 pm
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:-
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?
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:-
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?