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Discussion Starter #1 (Edited)
Recently adjusted the valves on 4BTA Scout. Wow, what a difference in performance. My fault, haven't adjusted the valves for so long. Like everybody else been using feeler gauges, Is that tight enough, is that too tight a pull. The P&G Valve gapper is no longer made, production stopped in the 60's, So decided to build my own.
It's 1.5" diameter, 2.25" long. There is a counter bore on the bottom that provides a lip to keep the body centered on the valve spring collar. Luckly Cummins made the collars flat so that simplified the design.
My initial method for using the tool is to pull the plunger up, set the tool on the valve spring, release the plunger and let it find the depression on the rocker arm tip. I've only tried this on my spare engines, hopefully this week I'll try it out on the Scout's 4B.
Edit: Found that the small tip on one of my dial indicators won't work, you need to use a tip with a large radius or possibly a flat tip. See last pic.
 

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that's some good engineering on that tool! But the standard method of using feeler gauges I believe is better in my opinion. the dial indicators don't have enough spring pressure that is needed to push down on the pushrod to push out the oil that is in between the rocker and rod and rod and the tappet. When you use the feeler gauges it is supposed to be tight to pull out so you know you have enough pressure on the valve train. there is a torque spec for the allen adjuster usually around 3-5 NM. I looked on quick serve for the B engine and it doesn't give anything but for all other cummins engines it lists a spec. I work for cummins here at the tech center in Columbus and this is common practice.
 

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Discussion Starter #3 (Edited)
Yes using standard feeler gauges is faster, but I will have to disagree about the "feel" being better. By pushing and pulling on the adjustment end of the rocker arm (to get the reading) I'm seeing no deviations in readings, so far. (not much anyway)
 

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Discussion Starter #5
I've used an indicator in a mag base holder, using my finger to move the rocker from the push rod end.
That was my first idea, but no platform close enough to all the valves to be able to use it, at least with my mag base holder and extensions. Second idea was to build a platform that attached to the rocker arm pedestal using the valve cover hole, The set up was a killer.
 

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Discussion Starter #6 (Edited)
I'd gone through 3 valve adjustments on my spare engine and was encountering different readings when checking. I found that if you slide the rocker arm on the shaft during the adjustment you get a different reading, as much as plus 5 mils over the initial setting. The culprit is the dimple in the tip of the rocker arm combined with the large radius on the tip of the indicator. It mandates a large flat tip on the indicator. Enco to the rescue. The tip kit should be here next wednesday.
 

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Do you have to hold it while it sits on the valve spring retainer or does gravity suffice?

Mag base is cumbersome. Your tool is a better solution. Any plans to make some for interested folks?
 

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Discussion Starter #8 (Edited)
Do you have to hold it while it sits on the valve spring retainer or does gravity suffice?

Mag base is cumbersome. Your tool is a better solution. Any plans to make some for interested folks?
I'm finding that the tool will sit on top of the valve spring just fine. With the engine at 5° incline installed in a vehicle, will find out. May have to deepen the counter bore on the base.
Any touching changes the readings. For checking the readings I use a push pull on the rocker arm adjusting end, so far.
I can supply a drawing package (SolidWorks 3D) after beta testing.
 

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Could you mill out another one or two of those tools?

I hated the ambiguity of feeler gauges with how tight it is. This seems to be a more precise (measureable) approach.
 

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Discussion Starter #10 (Edited)
Could you mill out another one or two of those tools?
I hated the ambiguity of feeler gauges with how tight it is. This seems to be a more precise (measureable) approach.
Right now working on a method of taking the measurements that gives repeatable readings.
Found that depending on how you move the rocker arm, a push on both ends of the rocker arm as opposed to a lift on each end of the rocker arm there can be as much as 5 mils difference in the reading.
More testing to be done before I can say it's a useful tool.
 

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Discussion Starter #11
Installed the flat tip on the dial indicator and found that the measurements are repeatable now using a push/pull on the adjustment end of the rocker arm. The range will move about a mill when you slide the rocker arm to either side of the rocker arm shaft but the total measurement is within half mill. Best method I've found is: you push down on the valve end of the rocker arm, zero the dial indicator and set the lash. Check using the push/pull on the adjustment nut and your done.
I think that the skirt around the valve spring needs to be a little longer (deeper counter bore) to prevent the tool from falling off from an accidental hit.
 

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Discussion Starter #14
Been working out the method for using the dial indicator. Trying to remember how the drag should feel using feeler gauges came across an idea using micrometers. Set the micrometer to the same reading as the feeler gauge, drag the feeler gauge through the micrometer, thats how the drag should feel. To be sure, I used a inch and a metric micrometer for checking.
One problem I've had using the tool is getting a consistent reading, because push the rocker arm against the pedestal you get one reading, slide the rocker arm away from the pedestal you get another reading, which is correct? The feeler gauge gave me the answer. When you use a feeler gauge the rocker arm will slide to the side with the largest gap, So use the largest reading and your done. And I found that to you have to use more force than I though you'd have to when checking the reading. That is if my feel on the feeler gauge is correct.
 

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Discussion Starter #18 (Edited)
Did the first Valve adjustment using the dial indicator tool on the Scout. I can't say that this tool eliminates using feeler gauges but it's a good double check. Case in point, several of the valves when adjusted with feeler gauges were found to be on the loose side by the tool. So now I know that those rocker arm tips have grooves making the use of feeler gauges inaccurate. Thats why I'd always have one or more valve clicking away after the valve adjustment, even after double and triple checks.
Video of after the valve adjustment, no clicking!
edit: Actually it's the new hydraulic lifter kit.:happyfinger:
 

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Discussion Starter #19
Feeling pumped up that the Scout Valve adjustment went well, decided to do my Dodge.

The tool didn't fit over the valve springs. Seems 60 lb springs have a larger diameter. Back to the drawing board.
 

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Guess you'll have to crank up the lathe again. The spring retainers have to be the same so I guess the spring is a little fatter. Always a learning curve.
 
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