Acceleration, or not so much...

[Hammerhead]

(08-12-2017 )BobLabla Wrote:  Very cool. Yeah, I was asking my mechanic and they charge some crazy 8 hours or so. F that! I'd feel better anyhow if I am finally responsible for it running correctly. I'm ordering all the tools, although I thought it was .014 and .027 but I'll check the Cummins site like ya say. I haven't seen anyone do the magnetic base and caliper test except for a Cummins made video on YouTube so that I need to look into a bit more. Thanks for the info tho and I hope to do a follow-up soon. Just hope nothing jumps out and bites me whaen I pull off the cover, as it's been quite a ruckus under there, and Jake's haven't worked for sh#* but maybe a tiny little bit when it's cooled down.

You are correct sir!
I made a mistake when writing my post and you had the common sense to verify and not just believe some hack posting crap on the Internet, good job! I have corrected my post as I don't want to spread bad info.

Yes, Cummins states 0.014" & 0.027" for intake and exhaust clearances on any of the ISX's I've worked on.

In another thread Rawze stated that Mr Hagg has shown him where 0.015" on the intake improves oil flow at operating temperature, which is why I recommend this clearance, but that is for you to decide.

If your jakes are weak, it may also be that your Jake rockers need new check valves and springs. When you run your overhead, if the Jake rockers don't "snap into & sit sharply" on the detents it is a good indication that; the springs are weak, the check valves are worn, and the rocker shaft detent holes are worn. I recommend replacing the springs every (2) years. There is no science behind this recommendation, it is simply that the springs are dirt cheap and theoretically the stronger they are, the better the seat the Jake rocker has in the detent and the less wear the check valves (next cheapest part) and hopefully prolong the life of the rocker shaft (the most expensive component of them).