Last year I took the makings a short motor to an engine builder for assessment. A Mk2 S block, small journal 1300 (tuftrided EN16T) crank and a set of rods.
When I pulled out the crank he had a look over it and then said he'd give it a ring test first to see if it was likely to have any cracks. I had done the same at home (some years ago) and thought it rang fine. However, when the engine builder gave it a try it rang like wet wood. I was a bit disappointed, but the crank had cost me nothing many years ago so I couldn't really complain. However, it looked Iike I was up for maybe $1,000 AUD to buy a new crank, and then a set of large journal rods to suit.
Anyway, fast forward to a couple of weeks ago, I was moving stuff around in my workshop. I picked up the crank that I had been meaning to tip and for some reason I grabbed a hammer when walking past the workbench and rang it - rings like a bell!
Trying to figure out what was going on, I finally twigged that the day we tried at the engine builders the crank had bolts loosely fitted in both ends that I had left in to keep the threads clean. I took them out when I brought it back home. Sure enough, when I replaced the bolts in the crank it would no longer ring - they had a significant damping effect.
So, just to be sure, I have had the crank and rods professionally NDT crack tested by a local specialist. All parts passed with flying colours - he even went over the crank twice for me.
Money well spent for me and I will be careful about relying on crank ringing in future.
Maddog (every day is a school day)
Crack testing and ringing cranks
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Re: Crack testing and ringing cranks
That is what I call a result.
Regarding a "ring" test, it is total bollocks.
A cracked crank, wheel or whatever will in a lot of cases ring just as true as uncracked one. If it is spectacularly cracked then you may be able to hear it, but in those cases, you will also be able see it.
If you want something crack testing either get it done professionally or buy yourself a DIY kit. Relying on old wives tails will either cost you a lot of money & a blown engine or mean you could be throwing a perfectly good crank away.
A kit like this one would probably last most of us a lifetime.
https://www.ebay.co.uk/itm/125724107241 ... BM-Pn08uph
Regarding a "ring" test, it is total bollocks.
A cracked crank, wheel or whatever will in a lot of cases ring just as true as uncracked one. If it is spectacularly cracked then you may be able to hear it, but in those cases, you will also be able see it.
If you want something crack testing either get it done professionally or buy yourself a DIY kit. Relying on old wives tails will either cost you a lot of money & a blown engine or mean you could be throwing a perfectly good crank away.
A kit like this one would probably last most of us a lifetime.
https://www.ebay.co.uk/itm/125724107241 ... BM-Pn08uph