Liner Height

[Starlight]

(01-29-2017 )Rawze Wrote:  

(01-28-2017 )Starlight Wrote:  I pulled all the liners and pistons. If the piston was devided into quarters then all the ring gaps would have been inside of one quarter. A couple of them had gaps lined up with each other. 1 piston had the top ring and and the second ring opposite of each other. Very poorly assembled to say the least. Then I cleaned up all the counterbore ledges to inspect and found all of them in mint condition with those tiny grooves that are there from the factory still nicely visible. The liners had the captive brass shims on them and they were obviously a bit worn from movement. The height from the deck to the counterbore ledge was a bit off at 4.7255 avg instead of the standard 4.724 spec. Basically the gasket had burned out because the protrusion too low and not because of fretting. Again very poor on Cummins part. The block surface is in very good shape with no warping or distortion. Block varies .001 thou from the front to the back which I don't think is something to be concerned about.

WoW!. That is the second factory reman engine I have heard about with rings having an incorrect alignment.

Just throwing this out there for others following this thread ...

With the mid-stop cut at 4.7255", this will usually put the newer liners right at 0.010". Typical height from factory. Sounds like it was the correct depth.

The minimum cummins says is is 0.007" liner height. 0.010" was still in spec, though I would not want to run it that way with the brass shims on the ledge myself.

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At least you are on the right track with it but I would check VERY VERY carefully, the under-side of the head for wear where the liners were dancing. All it takes is a 0.001" - 0.002"+ impression on the underside of the head and you are looking at uneven liner compression and problems all over again.

I am replacing the head, Its cracked in a coolant port causing coolant to form on one of the #6 exhaust valves. And yes there is obvious damage to the fire ring portion of the cylinder head on hole 4 that was burned out.