Gouge in cylinder bore - What would cause this?

joestewart · Mar 5, 2017

I am rebuilding a David Brown 1210 engine. When I pulled the pistons, I discovered this partially circumferential groove in one of the cylinder bores. See attached photos. A few of the piston rings were broken (but I can't remember if they were broken in this particular cylinder). The pistons look fine. I am wondering if anyone knows what could have caused this groove / gouge to form in this cylinder bore. Thank you.

RBoots · Mar 5, 2017

Just a guess here, but maybe that's the end of the ring travel for one of the ring lands on the piston. And maybe it was the one that had broken rings, or a loose ring, and the ring rocking in the ring land as the piston was coming down, then rocking as the piston headed back up could do it?

Ross

Olliejunkie · Mar 5, 2017

(quoted from post at 18:07:56 03/05/17) Just a guess here, but maybe that's the end of the ring travel for one of the ring lands on the piston. And maybe it was the one that had broken rings, or a loose ring, and the ring rocking in the ring land as the piston was coming down, then rocking as the piston headed back up could do it?

Ross

I would guess it was froze up in that position and that is from rust.

Bob Bancroft · Mar 5, 2017

I concur with the corrosion theory. Do you know if this engine sat for a time while it could corrode?

RBoots · Mar 5, 2017

Yeah, I just noticed that it does have some other pretty deep pits in the cylinder in areas other than that ring which would go along with the corrosion theory

rustred · Mar 5, 2017

looks like that cyl. had water sitting in it for a long time by all the pit marks. broken rings dont do that , but that sure will break them.

Steve@Advance · Mar 5, 2017

I'm guessing galvanic erosion, caused from acidic water sitting in the cylinder causing the dissimilar metals (iron and aluminum) to react, eroding the cylinder wall.

That will need to be bored, new rings will quickly fail with that deep of a ridge.

marloweg · Mar 5, 2017

that one had water in it bet that is the bottom of the piston travel and that grove is the top ring can see other pits in other places as well

joestewart · Mar 6, 2017

I bought the tractor in this condition. I do not know its history. But you are probably right when you say it had water in the cylinders at some point in its lifetime. I just thought it was strange that the corrosion selectively involved the cylinder walls. The pistons themselves appear to be in great condition (don't look corroded), and the motor was not seized (it spun freely). I will be bringing this engine to the machinist for boring. Thank you for all the replies.

Gouge in cylinder bore - What would cause this?

joestewart

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RBoots

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Olliejunkie

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Bob Bancroft

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RBoots

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rustred

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Steve@Advance

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marloweg

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joestewart

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