Dene Collett wrote: > Is there a formulae for working out what torque load a particular taper of a > particular length with a particular loading by a securing bolt in the centre > can handle without failing? Any of you engineers willing to > tackle this one?
Machinery's Handbook has this kind of thing in it, I'm sure. I'll try to remember to check it tomorrow. So do some of my old text books, but that would probably require that I figure out what a derivative is again. But my gut feeling is that I wouldn't dream of using that end of the crankshaft for a prop, especially behind a big engine. I realize that some folks are running big Type 4s and getting away with it, but there are plenty of stories of broken cranks in Type 4s floating around. Steve Makish had three crank failures in his T4, two of which were the 4340 Scat variety, and one was a stocker. (Too bad he departed KRnet a few months ago). You might could argue that something was amiss in the balance department, or something like that, but he's not the only one I've heard who's had crank problems. The bottom line is that VW designed that joint to pull a fan and an alternator, and the occasional air conditioner compressor, which is maybe 20 horsepower total. I wouldn't trust it to transmit 90 HP for hours on end, and many others have come to that same conclusion. Well, you already know my opinion. I'd run it off the crank end, where the power was meant to be delivered. If you're going to design something to take the gyroscopic loads anyway, I'd fasten it to the other end of the crank... Mark Langford, Huntsville, AL N56ML "at" hiwaay.net see KR2S project at http://home.hiwaay.net/~langford
