Repeated cylinder wall failure Allis 7030

In-framed this auction tractor in 2017. Came back in 2019 with 6 scuffed cylinders and one wasted. The initial diagnosis was overheating, because the sleeves all had ring of rust below the flange, each ring progressively lower going towards the rear of the tractor, as if the tractor were sitting in a nose-down position with the water level below the deck of the block. The theory being water loss during the winter and failing to check the water before starting in the spring. So, installed 1 new sleeve/piston group. The damage to the other 5 cylinders was such that you couldnt hook your fingernail in the scuff marks, and they cleaned up real nice with a light honing. But now she came back again. Didnt take all the cylinders out this time, but had one major failure. I have to rule out overheating this time, cuz the new S/P group right next to it is in perfect condition. Posted some photos. One thing I thought was strange was looking down the exhaust port with the head on, it was not sooty, but looked as clean as the day it came out of the box. And the non-uniform soot deposit on the under side of the head. What do you guys think? Thanks Fritz

The failed cylinder is No. 5, near the top in the cylinder head picture.

(quoted from post at 19:50:03 06/10/21) The failed cylinder is No. 5, near the top in the cylinder head picture.

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ooks like the cylinder is being washed down with fuel from a dribbling injector that is not spraying.

Ok, I think I got it all this time. The O.P. should read, looking down the port AT THE EXHAUST VALVE! The valve itself is soot-free.

did you put the air filter in that engine? overheating scuff's the piston skirts. meaning you loose all clearance and then you get metal transfer of the piston. then seizes up if not stopped. may an engine has be screwed by poor air filter fitting or hole in it.

What is the deck height on the sleeves to the head and how much difference is there? I will guess you cleaned all the crude out from the counter bore. If those sleeves are not with in about 2 thousandths it can leak coolant and look like that cylinder does burning coolant. Have you looked at the Bottom of the block around the top of the o-ring ? Is it corroded bad. Does the coolant pass an SCA test? If not it could have pinholes in the sleeves from not keeping the SCA's in line. Can be checked for holles by filling block with coolant or water and with a deck plate pressurize the block and watch for liquid in the bore of the sleeve or you can just pull that sleeve and examine for holes.

Looks like cvitation pits in the area above the to ring wear. If those go through, that is where the issue manifested. Has there been coolant conditioning and oil cooler maintenance done?? Jim

Havent pulled the sleeve yet but pulled the pan first to pressurize the system, and there is no water coming in. Protrusion was 0025 across the board. The area above the ring travel that looks like moon craters is a ring of carbon. Underneath it looks brand new. Not sure about the oil cooler question, about what needs to be done.

I have heard about this phenomenon in the past but
never seen it. Last time I had this tractor, I ran it
around the yard about an hour to see if any leaks
showed up. I was keeping an eye on the exhaust
for any unusual smoke signals, but didnt see
anything. But the guys that own the tractor never
tell me anything unless it quits or catches fire. My
point , if there is one, is it must be something going
wrong at peak operating temp, something that wont
occur driving around the yard.

Being that cylinder #6 looks like it is running warm as well I would not rule out the cooling system yet.

Cylinders 5 + 6 being the furthest from the rad and water pump are going to show heat related problems first.

Have the injectors tested before it goes back together.

Twice I have seen pistons melted into little balls of aluminum due to fueling issues.

They are already in the mail. We did 2 other
tractors, same supplier, no problems. This was the
only one that the pump and injectors were not
overhauled.