9U D6 Engine Overhaul

Is it getting up to temp? Has it been worked hard recently?

Without major blow by or oil consumption I would say look at the fuel system. What RPM is the engine running. Back 40 years ago I put a kit in one really did nothing. Had old guy check it out it was not running up to 1600 so we speeded it up, over shot the mark and ran it about 1700 high idle. Made a different tractor out of it.
At first Cat had them at 1400, but turned them up to 1600 latter on. The 318 engine in the DW 10 scraper was turned up over 2000 if I am not confused again. They did have a different governor and other parts on the engine made for the scrapers. But proves the bottom end can stand more RPM than the setting used in the D6.

Without major blow by or oil consumption I would say look at the fuel system. What RPM is the engine running. Back 40 years ago I put a kit in one really did nothing. Had old guy check it out it was not running up to 1600 so we speeded it up, over shot the mark and ran it about 1700 high idle. Made a different tractor out of it.
At first Cat had them at 1400, but turned them up to 1600 latter on. The 318 engine in the DW 10 scraper was turned up over 2000 if I am not confused again. They did have a different governor and other parts on the engine made for the scrapers. But proves the bottom end can stand more RPM than the setting used in the D6.

Suggest that if you have not yet done so to adjust the valve lash and get the injection pump lifter settings checked.
I know of overhauled engines that ran no better after overhaul than before due to incorrect lifter settings.
Cheers,
Eddie B.

[quote="edb" post=224764]Suggest that if you have not yet done so to adjust the valve lash and get the injection pump lifter settings checked.
I know of overhauled engines that ran no better after overhaul than before due to incorrect lifter settings.
Cheers,
Eddie B.[/quote]


can you give me all those specs, if you read my above post ive tried to find them with not much luck, seems like theres a different answer wherever i look.... thanks, i appreciate the help !

Hi,
looks like you posted that one while I was typing my answer so missed it.
Valve lash for both Inlet and Exhaust is 0.010" hot--adjust to around 0.012" initially cold seems to work and recheck when hot.
Also check the Inlet valve decompression system has clearance and so to be sure it is not holding the inlet valve off its seat--this clearance to the cutout on the decompression rod is about 0.125" ---this clearance is not adjustable and is a result of that all inlet valve train components are as per factory specs. this clearance may be found to be reduced usually when the inlet valve has recessed into the head --some clearance is required.

Lifter setting is 1.736" measured from top surface of the injection pump housing to the lifter yoke pad. This is done with the relevant piston at Top Dead center compression stroke---if you go past TDC turn the engine back at least 60 Degrees and come up to TDC again so as to remove any slack in the timing gear train.
TDC marks and pointer are on the front face of the flywheel as viewed thru the opening under a two bolt cover on the front right face of the flywheel housing--be aware the stamped marks will be hard to find as they will be covered by and filled by crud on the flywheel face.
Hope this helps.

Cheers,
Eddie B.

Hi Team,
yes, the D318 is also one of the engines that can have the flywheel out of sync with the crank--there are Factory chisel marks on both the flywheel and the crank that need to be aligned at assembly.
If the flywheel is out of sync then you need to establish your own TDC positions for the 3 required positions of crankshaft TDC--ie-- 1&6, 3&4, 2&5. or remove and refit the flywheel in the correct timed/sync position.
Cheers,
Eddie B.

Before things go sideways, is the 318 engine one of the ones that the flywheel can get out of sink with the marks? Or is it late enough that the flywheel only goes on the one way. With all the late model updates this could well be a machine that has had a lot of work done to it over time. This increases the chance of the flywheel having been off.

You don't say which 3 are not firing. But by chance is it the front 3? That would indicate linkage trouble with the compression release mechanism. Because the valve cover is 2 pieces and I don't remember how it all connects together. But if the valves are held open that would explain your problem. Just a random thought that would be easy to check. But I fear with the poorer quality of "new" diesel fuel, fuel problems will become more common.