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Mini Boring Bar From Motorcycle Poppet Valve
- Thread starter cascao
- Start date
4
4GSR
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One word of caution here, some valves are sodium filled and if cut, could explode on you. At least, that's what I've been told.
I've seen an example of a boring bar made from a very large valve about 1-1/2" diameter x around 40" long. They claimed it didn't vibrate or chatter when using it extended out 3 foot! I have a hard time believing that since the modulus of elasticity is constant in steels. With a 3 foot bending moment with a cutting load, the end of the boring bar will deflect a bunch! Say by about 1/4" or more!
I've seen an example of a boring bar made from a very large valve about 1-1/2" diameter x around 40" long. They claimed it didn't vibrate or chatter when using it extended out 3 foot! I have a hard time believing that since the modulus of elasticity is constant in steels. With a 3 foot bending moment with a cutting load, the end of the boring bar will deflect a bunch! Say by about 1/4" or more!
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- May 24, 2012
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- 395
My goal is to find smaller boring bar since brazed carbide boring bars easily cover bigger stuff. This one can work at holes from 8mm. But I will find one smaĺler soon.
On my test run it worked as spected. No chatter but used it at usual load and lenght.
On my test run it worked as spected. No chatter but used it at usual load and lenght.
A
Andre
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I have heard of people attaching carbide inserts to valves to use as rudimentary flycutters when depthening valve clearance on pistons. Video below by FiatNutz, he has a pretty cool channel and although runs an automotive machine shop, his videos are pretty good. Maybe you could attach a insert to the valve similar to what he did? I can't see all of your pictures, so you may have done that already, if so my bad.