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Original Message
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| I'm noisier than I am qualified. |
| By Dave Shoe - 07/03/2003 6:48:55 PM; IP 12.104.160.195 |
I bark a lot, but I do this mainly to get the folk who really know the answers riled enough to speak up and correct me.
I use the end support stands. I don't know why they work, but they do. They look like they'd be overstressed supporting the heavily cantilevered shaft tips, but it all seems to hold together.
Unfortunately, thicker shafts stink. If you could add metal to the O.D. that would help, but you can't. Adding metal to the inside diameter is deficient for two reasons:
1) Adding metal to the ID of a thick tube simply can't add much stiffness. The added metal is simply too close to the center that it makes the shaft insignificantly stiffer. The FE rockershaft needs a lot of stiffening, not a little.
2) The specific weak spot of the FE rockershaft is at the end pedestal bolt holes, and since the additional material of a thicker shaft added near the bolt hole is simply drilled right out, you actually create a stress raiser at the hole, where the entire tube flexes slightly less but the area at the hole remains just as flexible.
Hardened shafts are good for one thing: reducing wear. Since wear is not an issue, bending and breakage is, a hardened shaft will likely develop fatigue cracks and snap sooner than a less hardened shaft. "Hardening" does not increase the rigidity of the shaft at all. A hardened shaft flexes as easily as a non-hardened shaft. The difference can be found at higher stress levels, as a hardened shaft will behave differently than a non-hardened shaft as the yield points are reached.
Stock shafts simply weigh less than thick shafts, and they have about the same ultimate strength (in my opinion - many will argue this). I use end supports similar to the $119.95 jobbies, but there are many designs which are better, though price does climb to suit the complexity.
I'll cut it off right here in the middle. I could rant on. To keep it simple, the end supports are the best "first line" of defense for FE rockershafts, an are all that most folk will need. I feel it's a very important upgrade for any FE with non-stock cam. That doesn't mean I'm right, and my opinion might change someday.
Shoe. |
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This thread, so far...
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