Because this is not a high-revving powerhouse of an engine, the rod would probably have stood up in normal operation. But the consequences of that "probably" being wrong would be catastrophic. Below are a couple of photos of the carnage after a different MG engine "threw a rod," punching a hole in the side of the block, and even smashing the oil filter canister.
As Dave Cummings pointed out in a comment, the rod had been "compromised" when Brutus twisted it. Then, I added to that by twisting it back! I had become focused on the fact that I COULD straighten the rod, and lost sight of the fact that I SHOULDN'T.
But you can't replace just one connecting rod (or at least you shouldn't). They should always be kept as a matched and balanced set.
Fortunately, the local MG restoration shop in Mesa had a set of reconditioned rods on the shelf. They had been professionally sized, balanced, bead-blasted, and magnafluxed to find any microscopic flaws. Un-fortunately, that was another Brutus-induced $400 cost-overrun. (Still, that's a fraction of what it would cost if the twisted rod failed.)
So, feeling a little like a pit crew (pit person?), I took the engine completely apart, which included removing all of the piston rigs to get the pistons out and back in, replaced all the rods, and now have the bottom half of the engine back together, again. I just need to get some new cotter pins and I'll be back to square-one.
(My thanks to Dave, Scott, and Skip for your cautionary input!)
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| Rod through the side of an MG PB engine. |
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| It even took out the oil filter canister. |
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| Old rods (dark) vs. reconditioned rods. |
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| Back to square-one once the cotter pins are installed. |
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