Magnafluxing question
01-09-2002, 10:56 AM
#1
Melting Slicks
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Magnafluxing question
I know what magnafluxing is (i think) but this quesion came up at lunch the other day. OK you get a block and have it magnafluxed to check for small cracks and inperfections. If you find none, great! Get building! However what if you find a crack. If it's a used block then are you SOL? If it's a new block purchased from a vendor will they replace it. Whould you have to argue what is a "critical crack" and what is "normal".
When you read a engine building article in a magzie they say "we magnafluxed, hot tanked etc... the block and then get started building it up. They never mention what would happen if they found a critical crack.
Just curious...It'll be good knowledge for when I get around to replacing the SB with the correct BB.
[Modified by Monkeywrench, 9:57 AM 1/9/2002]
When you read a engine building article in a magzie they say "we magnafluxed, hot tanked etc... the block and then get started building it up. They never mention what would happen if they found a critical crack.
Just curious...It'll be good knowledge for when I get around to replacing the SB with the correct BB.
[Modified by Monkeywrench, 9:57 AM 1/9/2002]
01-09-2002, 11:10 AM
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Drifting
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Re: Magnafluxing question (Monkeywrench)
I've seen rods magnafluxed but I've never seen an entire block done. I've heard of cracked blocks being welded but the problem I see is what if the crack caused some critical dimension (piston bore, bore center, crank centerline, etc.) to shift?
01-09-2002, 12:30 PM
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Melting Slicks
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Re: Magnafluxing question (Neo Fender)
I've seen rods magnafluxed but I've never seen an entire block done. I've heard of cracked blocks being welded but the problem I see is what if the crack caused some critical dimension (piston bore, bore center, crank centerline, etc.) to shift?
01-09-2002, 01:08 PM
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Re: Magnafluxing question (Monkeywrench)
No one in their right mind would proceed forward with a rebuild without first checking the block for cracks. Finding a crack after investing $5k in machining and rebuild costs is not good for your wallet or sanity.
Normally, the block is hot-tanked or, more common these days, baked to remove the crud. Then it is magnafluxed to check for cracks. An electromagnet is applied to the block and ferrous metal filings are puffed out of an applicator at the block. Cracks show up readily when the filings line up along the fracture.
What is done when a crack is found depends on; location of the crack and cost of replacement. If the crack is in a repairable location, the next question is, is it worth the cost? For example, if you have a numbers matching block for a rare combo, you might be more inclined to spend a few bucks on a repair versus buying a new one.
Normally, the block is hot-tanked or, more common these days, baked to remove the crud. Then it is magnafluxed to check for cracks. An electromagnet is applied to the block and ferrous metal filings are puffed out of an applicator at the block. Cracks show up readily when the filings line up along the fracture.
What is done when a crack is found depends on; location of the crack and cost of replacement. If the crack is in a repairable location, the next question is, is it worth the cost? For example, if you have a numbers matching block for a rare combo, you might be more inclined to spend a few bucks on a repair versus buying a new one.
