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Hi guys,

This is my first post, but I have been using this forum to help me restore my M37. It has been a wealth of knowledge and inspiring to say the least.
But I have hit a road block in rebuilding the engine. I have a block from 1959 (Stamped M230) and it has been bored out to fit .080 pistons. First off,
I have checked the top of the pistons and they are stamped .080 and measured they are that big. Some of the walls have some scoring and I don't
think honing will clean it up. The first cylinder has a sleeve installed and rest are bored. The service manual for the motor says .060 is the biggest recommend. Has anyone gone bigger than .080 or even seen a motor last running with bore job this big? I did have the motor running before the tear down and it sounded good and didn't smoke. At this point I don't really know what I should do and any advice would be great. I am thinking I need to find a different core.

Thanks Shane

P.S Here is the day I picked it up.

If you want to keep the block, sounds like you'll need to sleeve the cylinders (and replace the sleeve in the one cylinder that was already sleeved, since it's been bored 0.080" over) back to standard bore. Sleeves are not very expensive (around $15 per cylinder), but the machining and installation will set you back a bit.

If you decide you want to sleeve it, check the rest of the block first. It may have other problems that make it impossible or economically unreasonable to save it.

Provided you can find a replacement T245 or T245A block somewhere close and in good shape, I'd go that route. Or maybe you're open to a re-power?

Thanks for the reply. Just found a replacement engine so I am going to start fresh.

Shane,
Have you gotten your replacement engine disassembled and inspected yet?
I got my second engine pulled out of my M43 this weekend, and got it disassembled far enough to find a perfect standard engine internally. Not even a wear step in the original bores, and standard journals on the crank.
Hope your second engine is good as well!
Your picture looks like you have a solid candidate for a good restoration!
DCook