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Checking Alu Case for Stress Cracks Post Accident
There is a 3.2 motor I am looking at buying that came out of a crashed car.
One of the biggest concerns is that the transmission took a big lateral hit. We are concerned that the flange on the engine case where the bell housing bolts up, might have been stressed. What is a good way to test this once the motor is all apart? Magnaflux dye test (SpotCheck)? Or some other way? All looks OK externally but don't want to rebuild this motor only to discover a crack, and it leaks ! TIA, R.
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Robert Callaway PCA | Early S Registry | R Gruppe 1970 T Coupe, 1990 C2 Coupe, 2007 Cayman S 1962 S90 Coupe - Gone, but never forgotten... 1985 Targa - A distant memory... Last edited by superninety; 12-22-2020 at 11:56 AM.. |
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12-21-2020, 09:44 AM
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Having the motor disassembled would certainly allow closer inspection, die testing, etc.
I'm thinking the impact to the transmission, probably via a wheel and axle, imposed more of a compression load on one side of the engine case, and a tension load on the other, and not so much of a shear load. If one of the ears of the tranny broke, that might suggest where to look more carefully at the corresponding part of the engine case? The case is pretty stout. |
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12-21-2020, 02:08 PM
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Thanks Walt.
Yes, I'm working with my shop, who owns the motor. We will disassemble and inspect the bare case halves. If they are cracked or if the crank has issues, I don't pay anything, so, no worries. Thus far no noticeable broken ears. Will keep you posted.
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Robert Callaway PCA | Early S Registry | R Gruppe 1970 T Coupe, 1990 C2 Coupe, 2007 Cayman S 1962 S90 Coupe - Gone, but never forgotten... 1985 Targa - A distant memory... |
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12-21-2020, 02:21 PM
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An easy check would be how perpendicular the engine to transmissions studs are and then go from there.
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12-21-2020, 03:53 PM
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The case is cast aluminum so if there is damage from the accident it should be apparent.
Turn the crank and see if its free. Do a leak down test |
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12-21-2020, 08:00 PM
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A blue led light off amazon will work.i bought this to find ticks on my black lab.turns out it works great to find residue et inside engine cases after vapor blasting.
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12-22-2020, 05:27 AM
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Camera has a hard time photographing but you get the idea,should work well for any cracks
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12-22-2020, 05:32 AM
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$12 off amazon
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12-22-2020, 05:34 AM
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Almost forgot, buy some crack dye, magnaflux makes a bunch of different dyes you can pick up a can for $20. The white dye and the $12 led flashlight and your good to go. Welders often use different types of spray on dyes to check cracks, welds et.
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12-22-2020, 10:32 AM
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Magnaflux dye test (SpotCheck)? Yes, mentioned it in the first post, if we are talking about the same thing.
Thanks !
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Robert Callaway PCA | Early S Registry | R Gruppe 1970 T Coupe, 1990 C2 Coupe, 2007 Cayman S 1962 S90 Coupe - Gone, but never forgotten... 1985 Targa - A distant memory... |
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12-22-2020, 11:56 AM
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Magnaflux Corp has crack testing products for ferrous only materials (steel). They also developed Zyglo, a dye penetrant for crack testing non-ferrous materials:
https://www.hunker.com/13416275/how-to-check-aluminum-for-stress-cracks-with-magnaflux http://site.ndtsupplies.com/instructions/Zyglo_Bulk_Operating_Instructions.pdf Sherwood |
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12-22-2020, 03:12 PM
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