Long 610 - Engine Knock

NatWester

Member
Long 610 4 cylinder 102mm. Full engine rebuild: new pistons/rings, cylinders honed, new rod bearings, and a complete gasket set. Before the rebuild, I had the injection pump and all the injectors rebuilt. But it sounds like it's knocking, and it gets worse when rpms go up. It's not the valves or the injection pump timing. Note: At idle, oil pressure is 25psi, revved up it's over 50psi. I've got about 2 hours total of run time, and I don't think
🤞
the knocking has gotten any worse.....
1st pic: I took the oil pan off
🤔
and found 2-3 little pieces of aluminum (old piston -2nd pic- pieces I missed when I flushed it out?)
3rd & 4th pic: It's the top side of the counter-balancer/oil pump (what are those 2....spots? I can't tell what they're for)
5th pic:
🤔
if you look closely, it looks like fresh rub marks on that spot
6th pic: rod bolt idk if it's got fresh rub marks on it -white arrow- but I can feel a burr when I run my finger across it. Red arrow, it looks like it's got hot at some point
last 3 pics: rod bearing
 

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Long 610 4 cylinder 102mm. Full engine rebuild: new pistons/rings, cylinders honed, new rod bearings, and a complete gasket set. Before the rebuild, I had the injection pump and all the injectors rebuilt. But it sounds like it's knocking, and it gets worse when rpms go up. It's not the valves or the injection pump timing. Note: At idle, oil pressure is 25psi, revved up it's over 50psi. I've got about 2 hours total of run time, and I don't think
🤞
the knocking has gotten any worse.....
1st pic: I took the oil pan off
🤔
and found 2-3 little pieces of aluminum (old piston -2nd pic- pieces I missed when I flushed it out?)
3rd & 4th pic: It's the top side of the counter-balancer/oil pump (what are those 2....spots? I can't tell what they're for)
5th pic:
🤔
if you look closely, it looks like fresh rub marks on that spot
6th pic: rod bolt idk if it's got fresh rub marks on it -white arrow- but I can feel a burr when I run my finger across it. Red arrow, it looks like it's got hot at some point
last 2 pics: rod bearing
Mark the rod caps to their cylinder, then pull the caps off all the rods and compare what the bearing look like.
When you rebuilt it did you check the crankshaft/connecting rod bearing clearance with plastigage?
Did you have the crank ground?
What did the bearings on the crank measure at?
What size bearings did you put in?
Did you make sure you lined the oil holes in the bearing up with the holes in the connecting rod?
Did you oil the rod bearings before you installed them?
 
What was the original reason for the rebuild? Was it knocking before?

Edit...never mind, I missed the broken piston ring land in the pic.
 
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6th pic: rod bolt idk if it's got fresh rub marks on it -white arrow- but I can feel a burr when I run my finger across it.
Did you accidentally drop any of the bolts during the process? The mark could come from that. Does this engine have a balancer unit that bolts under the crankshaft. If so maybe some inadvertent contact was made during assembly.
Red arrow, it looks like it's got hot at some point
last 2 pics: rod bearing
Crankshafts are induction hardened when they are made. To me the coloring that is showing may just be left over from that process. Here is a video that shows the process at 1:15 - 2:04. Crank induction hardening
If the rod bearings you’re showing are from that rod I don’t think you have a problem there. If they are from another rod I would make sure to look at the ones on that throw before reassembly.
Was this and in-frame overhaul? If not and the engine was completely out of the tractor I would reevaluate your cleaning techniques. If an in-frame those pieces could have been in the front cover of maybe up around the cam. I am not familiar with that engine so I can’t say what the area around the cam is like, whether it could possibly hold anything or not. I assume you rotated the engine to make sure there is no skirt or bottom side damage on any of the pistons.
I am going to make a guess on the “spots” as being plugs for oil passage drillings, maybe lead.
 
Mark the rod caps to their cylinder, then pull the caps off all the rods and compare what the bearing look like.
When you rebuilt it did you check the crankshaft/connecting rod bearing clearance with plastigage?
Did you have the crank ground?
What did the bearings on the crank measure at?
What size bearings did you put in?
Did you make sure you lined the oil holes in the bearing up with the holes in the connecting rod?
Did you oil the rod bearings before you installed them?
Yes, plastigage: all 4 were 0.0015-0.002
No, I didn't take out the crank or do mains
Rod bearings were std
Yes, I lined up holes
Oil? I used Vaseline
Mark the rod caps to their cylinder, then pull the caps off all the rods and compare what the bearing look like.
When you rebuilt it did you check the crankshaft/connecting rod bearing clearance with plastigage?
Did you have the crank ground?
What did the bearings on the crank measure at?
What size bearings did you put in?
Did you make sure you lined the oil holes in the bearing up with the holes in the connecting rod?
Did you oil the rod bearings before you installed them?
Yes, plastigage: all 4 were 0.0015-0.002''
No, I didn't take out the crank or do mains
All the rod bearings were std, old & new
Yes, I lined up the holes
Oil? I used Vaseline
1st pic - old
2nd pic - new
 

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Long 610 4 cylinder 102mm. Full engine rebuild: new pistons/rings, cylinders honed, new rod bearings, and a complete gasket set. Before the rebuild, I had the injection pump and all the injectors rebuilt. But it sounds like it's knocking, and it gets worse when rpms go up. It's not the valves or the injection pump timing. Note: At idle, oil pressure is 25psi, revved up it's over 50psi. I've got about 2 hours total of run time, and I don't think
🤞
the knocking has gotten any worse.....
1st pic: I took the oil pan off
🤔
and found 2-3 little pieces of aluminum (old piston -2nd pic- pieces I missed when I flushed it out?)
3rd & 4th pic: It's the top side of the counter-balancer/oil pump (what are those 2....spots? I can't tell what they're for)
5th pic:
🤔
if you look closely, it looks like fresh rub marks on that spot
6th pic: rod bolt idk if it's got fresh rub marks on it -white arrow- but I can feel a burr when I run my finger across it. Red arrow, it looks like it's got hot at some point
last 3 pics: rod bearing
I know you say thats not it but Your video clip sounds more like loose valve lash, or a exhaust leak than a knock. Bent push rod?? Its hard to tell however if there is a more pronounced knock at idle? I take it pistons came with new pins and you installed and sized the wrist pin bushings?
 
Is there any chance that you got two rod caps mixed up?
If you plastigauged all 4 and they all looked good this probably isn’t your problem.
To Nat: After a new rod bearing is installed and torqued I check for forward/aft motion or slide just to verify nothing is to tight, the top of the rod also slides in the wrist pin. I actually use a small hammer lightly tapping at an angle on the bolt side of the rod in each direction feeling the opposite side between left hand thumb and forefinger. Also can catch if it might feel to loose. Hard to explain without being shown and there is some learning to the process.
 
I pulled off a main cap today.... not the prettiest but idk if it's bad enough to cause the knocking. It looks like it's been like that for awhile
 

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