Acceleration, or not so much...

[Hammerhead]

(08-12-2017 )BobLabla Wrote:  Anyone have the nuts to do the overhead themselves?!? I think I may buy what I need to do it so I can stay on top of it once a year. But first I need to make sure the injectors are all doing what they are supposed to. I just hope I don't go through it all and have some kind of blockage in the fuel system.

Running an overhead is not hard to do, it's a great first procedure. If you don't already have a Quickserve.cummins.com account, go create one. Go into the service manual and print the procedure out, and follow it step by step. If you can tackle this, it will help give you the confidence to build your mechanical altitude and soon you'll be doing your own inframe...

Tools needed for the overhead once the rocker cover has been removed:
3/4" drive ratchet and a short extension-used to bar the motor over
A dial or split beam type torque wrench(small increments, value is 71in/lbs-8Nm) with an 8mm Allen socket-for adjusting injector preload on dual cam engines (570, 870, 871)
A torque wrench for the adjuster jam nuts(range of 15-50 ft/lbs)-multiple is nice so you don't have to change settings from injector to valve to jake every cylinder
A 6mm Allen wrench-for the valve adjuster
A 3mm Allen wrench-for the Jake adjuster
A 24mm socket for the injector jam nut
A 19mm crows foot-for the valve jam nuts
A 13mm crows foot-for the jake rocker
A 0.015" feeler-for the intake valve clearance (0.014" is Cummins stated clearance, Mr Hagg has found increased oil flow with 0.015" which is why I recommend this)
A 0.027" feeler-for the exhaust valve clearance
A 0.276" or 7mm feeler (or stack of feelers equal to)-for the jake rocker clearance
*A dial indicator and magnetic adjustable base to measure jake detent to valve pin clearance after adjustment

Your first time will take you the best part of the day...

Verify all of the above in YOUR specific procedure! I made a mistake when originally posting this and stated 0.024 for the exhaust clearance! Everyone makes mistakes, so always verify with the procedure. The procedure also says 0.14" for the intake, but Mr Hagg has shown Rawze how much better the oil flows by increasing the intake to 0.015", which is why I stated that clearance instead, it's up to you to decide if you chose that or not.

*Another trick if you don't have a dial indicator and magnetic base; after the jake rocker is adjusted, rock it back towards the cam, place and hold a 0.030" feeler on top of the exhaust valve where you had the 0.276"/7mm feeler. Now rock the jake rocker into the detent position. Now push the jake rocker down towards the valve, if you still have slight clearance your head is good. If you have none, watch the jake rocker very closely while you slide the 0.030" feeler out flat, if it moves DOWN further into the detent, your clearance is at or beyond critical. This is how I do it when I don't have my dial indicator with me.