Manley Billet 100mm crank - Cracked
true, but these billet cranks are $1300. They could easily say it's 8 years old and anything can cause the failure and leave you hanging. So yes, there were labor costs. But OP doesn't need to buy another crank.
Just thinking out loud:
Its very likely Manley has investigated this failure & have accepted that many of these failures are their responsibility
They are providing a "parts only" contribution to limit their financial exposure. Id bet their true cost on that crank is $400-450
Its very likely Manley has investigated this failure & have accepted that many of these failures are their responsibility
They are providing a "parts only" contribution to limit their financial exposure. Id bet their true cost on that crank is $400-450
Also, I now see how damper actually helps crank at #4 rod. I'll share later since it's going to take time to explain.
Nice ideas guys, I agree with much of what was said.
Something I always wonder about....
If we are looking at a crankshaft from the top, the power generated from pistons/rods 1,2, and 3 is transferred to the flywheel side of the crank through rod journal #4. ALL(minus friction losses and windage) of the power coming from 75% of the engine has to pass through that sorry little rod journal #4 before it can get to the final main journal and then the flywheel, at which point we can send it. Rod Journal #4 is also responsible for absorbing and transferring the power generated from piston rod assembly #4. The main journals are already thick as hell in diameter and have no trouble transferring the power of the adjacent cylinders through the crank, but how can we rely on one much smaller rod journal to do the same job?
Compare it to a gauge change in a wire. If you have someone using 0 gauge wire to send 150 amps into a room, but uses 20 gauge wire of equal length to connect it to the load, you're going to obliterate that 20 gauge wire if the load needs the full current. We are asking a lot of our cranks.
It's almost as if the rod journals would have to get progressively bigger as they approach the flywheel side in order to truly carry the power generated by the previous cylinders. The problem with this is that it puts the crank WAY out of balance and you would have to notch cylinders 2,3,and 4 to clear the larger piston rod big ends that would be needed lol. Thus, the solution was to build the crank out of a material strong enough such that the rod journals 1, 2, and 3 are over-engineered (stronger than what is needed) and #4 is good enough.
Solution: I think OEM crank, keeping it under 350 wheel trq,,,but that's not very fun now, is it?
I would hate to be a rod journal #4.
Something I always wonder about....
If we are looking at a crankshaft from the top, the power generated from pistons/rods 1,2, and 3 is transferred to the flywheel side of the crank through rod journal #4. ALL(minus friction losses and windage) of the power coming from 75% of the engine has to pass through that sorry little rod journal #4 before it can get to the final main journal and then the flywheel, at which point we can send it. Rod Journal #4 is also responsible for absorbing and transferring the power generated from piston rod assembly #4. The main journals are already thick as hell in diameter and have no trouble transferring the power of the adjacent cylinders through the crank, but how can we rely on one much smaller rod journal to do the same job?
Compare it to a gauge change in a wire. If you have someone using 0 gauge wire to send 150 amps into a room, but uses 20 gauge wire of equal length to connect it to the load, you're going to obliterate that 20 gauge wire if the load needs the full current. We are asking a lot of our cranks.
It's almost as if the rod journals would have to get progressively bigger as they approach the flywheel side in order to truly carry the power generated by the previous cylinders. The problem with this is that it puts the crank WAY out of balance and you would have to notch cylinders 2,3,and 4 to clear the larger piston rod big ends that would be needed lol. Thus, the solution was to build the crank out of a material strong enough such that the rod journals 1, 2, and 3 are over-engineered (stronger than what is needed) and #4 is good enough.
Solution: I think OEM crank, keeping it under 350 wheel trq,,,but that's not very fun now, is it?
I would hate to be a rod journal #4.
Nice ideas guys, I agree with much of what was said.
Something I always wonder about....
If we are looking at a crankshaft from the top, the power generated from pistons/rods 1,2, and 3 is transferred to the flywheel side of the crank through rod journal #4. ALL(minus friction losses and windage) of the power coming from 75% of the engine has to pass through that sorry little rod journal #4 before it can get to the final main journal and then the flywheel, at which point we can send it. Rod Journal #4 is also responsible for absorbing and transferring the power generated from piston rod assembly #4. The main journals are already thick as hell in diameter and have no trouble transferring the power of the adjacent cylinders through the crank, but how can we rely on one much smaller rod journal to do the same job?
Compare it to a gauge change in a wire. If you have someone using 0 gauge wire to send 150 amps into a room, but uses 20 gauge wire of equal length to connect it to the load, you're going to obliterate that 20 gauge wire if the load needs the full current. We are asking a lot of our cranks.
It's almost as if the rod journals would have to get progressively bigger as they approach the flywheel side in order to truly carry the power generated by the previous cylinders. The problem with this is that it puts the crank WAY out of balance and you would have to notch cylinders 2,3,and 4 to clear the larger piston rod big ends that would be needed lol. Thus, the solution was to build the crank out of a material strong enough such that the rod journals 1, 2, and 3 are over-engineered (stronger than what is needed) and #4 is good enough.
Solution: I think OEM crank, keeping it under 350 wheel trq,,,but that's not very fun now, is it?
I would hate to be a rod journal #4.
Something I always wonder about....
If we are looking at a crankshaft from the top, the power generated from pistons/rods 1,2, and 3 is transferred to the flywheel side of the crank through rod journal #4. ALL(minus friction losses and windage) of the power coming from 75% of the engine has to pass through that sorry little rod journal #4 before it can get to the final main journal and then the flywheel, at which point we can send it. Rod Journal #4 is also responsible for absorbing and transferring the power generated from piston rod assembly #4. The main journals are already thick as hell in diameter and have no trouble transferring the power of the adjacent cylinders through the crank, but how can we rely on one much smaller rod journal to do the same job?
Compare it to a gauge change in a wire. If you have someone using 0 gauge wire to send 150 amps into a room, but uses 20 gauge wire of equal length to connect it to the load, you're going to obliterate that 20 gauge wire if the load needs the full current. We are asking a lot of our cranks.
It's almost as if the rod journals would have to get progressively bigger as they approach the flywheel side in order to truly carry the power generated by the previous cylinders. The problem with this is that it puts the crank WAY out of balance and you would have to notch cylinders 2,3,and 4 to clear the larger piston rod big ends that would be needed lol. Thus, the solution was to build the crank out of a material strong enough such that the rod journals 1, 2, and 3 are over-engineered (stronger than what is needed) and #4 is good enough.
Solution: I think OEM crank, keeping it under 350 wheel trq,,,but that's not very fun now, is it?
I would hate to be a rod journal #4.
I'll add more later to make things worse for #4
