Keyway damage - what caused it, what prevents it ?
#21
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In racing sometime you have to go above-and-beyond for reliable fasteners. Turbo bolts are well covered here, folks run high end stuff to make sure fasteners work right. For a crank bolt stock spec is probably fine. Since I ran a SC back when I put that bolt on I torqued it to 150 and put red loc tite cause SC guys strip the keyway with extra loading a lot more often than other folks. And I ran a lot of boost and a big SC, so I was pullling 100+ hp off the crank to drive that blower. Probably overkill but better than a failure from that bolt vibrating loose or stripping the key. For a crank bolt I'd rather over than under tighten that bolt, since under torque is very likely going to end like it did for the OP here.
On my converter bolts, I torqued them to 40-50 ft*lbs (7/16 grade 8 bolts) and they vibrated loose in about 10 miles! After searching some drag racing forums, the known to work fix is 80-90 ft*lbs and lots of red loc-tite. I did that, problem solved. Have a couple thousand miles on it now and so far bolts haven't moved. For the curious, that's not factory spec because factory spec on those doesn't work reliably in a drag car.
On my converter bolts, I torqued them to 40-50 ft*lbs (7/16 grade 8 bolts) and they vibrated loose in about 10 miles! After searching some drag racing forums, the known to work fix is 80-90 ft*lbs and lots of red loc-tite. I did that, problem solved. Have a couple thousand miles on it now and so far bolts haven't moved. For the curious, that's not factory spec because factory spec on those doesn't work reliably in a drag car.
#25
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Ditto. The FSM doesn't specify it as a TTY bolt, but I replace it (and the key) on every motor I build. The exceptions are on my own personal motors during maintenance, since I know the bolt was replaced and has never been overtorqued.
#29
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Still waiting to see what the used crankshaft I'm after looks like. Going to get my wrench tested (for free!) I'll definitely be buying new hardware. Won't be for a few.eeeks at least.
Thanks for all the discussion.
Thanks for all the discussion.
#32
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Got some pictures of the used crank I'm thinking about using. Not sure that I like it. I see some grooves and wear on the oil seal surface and some bearing surfaces look rough? not to mention there is slight keyway wear as well. What do you think ?
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That keyway is already hosed. Why start out with bad when good ones are available?
Contact Partsgroup.com. They've always done alright by me.
http://partsgroup.com/part/1994-2005...00c-bp0611300c
Contact Partsgroup.com. They've always done alright by me.
http://partsgroup.com/part/1994-2005...00c-bp0611300c
#38
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I have always wondered why there is not a better field repair for this common problem.
I was thinking something similar to what they do for GM LS motors for superchargers. Like this:
Pinning the crank pulley - LS1GTO.com Forums
I was thinking something similar to what they do for GM LS motors for superchargers. Like this:
Pinning the crank pulley - LS1GTO.com Forums