New crank cracked?
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Re: New crank cracked?
There ya go! How soon we forget.
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Re: New crank cracked?
Here is a good example of a crank someone needs advice on,351 cleveland crank.
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Re: New crank cracked?
welded journal. Always tough call on whether it's a real crack or a weld void / overlap.
Even a nicely welded cranks looks like doo doo under the black light.
Even a nicely welded cranks looks like doo doo under the black light.
Dave Koehler - Koehler Injection
Enderle Fuel Injection - Nitrous Charger - Balancing - Nitrous Master software
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"Never let a race car know that you are in a hurry."
Enderle Fuel Injection - Nitrous Charger - Balancing - Nitrous Master software
http://www.koehlerinjection.com
"Never let a race car know that you are in a hurry."
Re: New crank cracked?
Here are some closer pix. Best I can do.
May actually be forging void as suggested.
Safe to run?
May actually be forging void as suggested.
Safe to run?
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Re: New crank cracked?
I'd run that, yeah.
Looks very much like a casting/machining overlap, and its on the backside anyways.
If the ocd kicks in hard just have it ground.
Looks very much like a casting/machining overlap, and its on the backside anyways.
If the ocd kicks in hard just have it ground.
Magnús Aðalvíkingur Finnbjörnsson
Re: New crank cracked?
I wouldn't use it without cleaning it up. Any surface discontinuity is a stress riser. It will probably be fine, but I tend to err on the side of caution if given the option.Truckedup wrote: ↑Thu Apr 11, 2019 8:26 amIf so, is the crank usable for high performance ? Grind it undersize to try and clean it up?MotionMachine wrote: ↑Thu Apr 11, 2019 8:21 amI tend to agree with this. Especially considering it's in line with the forging seam. When I've seen cracks like in the pic Scotty posted, they were caused from heat, just like cracks in the face of a flywheel. I've tried to grind them out but rarely do they go away with a minimal grind. Since the crank is new, it hasn't been subject to any trauma. I think it just didn't clean up completely from the rough forging when it was ground.
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Re: New crank cracked?
Cracks don't stop and re-start as in the first of the close up pix. I bet the crank rings vs. thuds if it's hung on a wire and tapped with a hammer.
Also, it's in a low stress region. I run it with no worries.
Also, it's in a low stress region. I run it with no worries.
Felix, qui potuit rerum cognscere causas.
Happy is he who can discover the cause of things.
Happy is he who can discover the cause of things.
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Re: New crank cracked?
For OP, not RE: that nasty-*ss welded crank.
I agree the "seam" is not in the worst orientation, and assume it does truly not extend into the fillet/radius, although visual is not the best way to ascertain that.
Is this build it and forget it?
Or, is the pan going to come off several times a year for inspection, so the crack/seam could dye penetrant tested to monitor "progess?"
I agree the "seam" is not in the worst orientation, and assume it does truly not extend into the fillet/radius, although visual is not the best way to ascertain that.
Is this build it and forget it?
Or, is the pan going to come off several times a year for inspection, so the crack/seam could dye penetrant tested to monitor "progess?"
Re: New crank cracked?
Ideally I don't want to touch it after building but I won't sleep easy. It does continue into the radius which is why I'm concerned. Even if it's a welding void, surely it can't be good in the radius. Barely visible there...but nonetheless.
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Re: New crank cracked?
uhhh, wait a minute. After all this you still haven't had it tested? That's on you.
Dave Koehler - Koehler Injection
Enderle Fuel Injection - Nitrous Charger - Balancing - Nitrous Master software
http://www.koehlerinjection.com
"Never let a race car know that you are in a hurry."
Enderle Fuel Injection - Nitrous Charger - Balancing - Nitrous Master software
http://www.koehlerinjection.com
"Never let a race car know that you are in a hurry."
- Dave Koehler
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Re: New crank cracked?
OK, but you have been shown how to check it yourself via 2 or 3 methods, ranging from free to not real expensive. Become that guy.
Dave Koehler - Koehler Injection
Enderle Fuel Injection - Nitrous Charger - Balancing - Nitrous Master software
http://www.koehlerinjection.com
"Never let a race car know that you are in a hurry."
Enderle Fuel Injection - Nitrous Charger - Balancing - Nitrous Master software
http://www.koehlerinjection.com
"Never let a race car know that you are in a hurry."