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One way to determine piston position for valve adjustments
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56D500boy
Posted 2017-06-08 5:59 PM (#541816)
Subject: One way to determine piston position for valve adjustments



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I have stalled myself on my D500 project because I wasn't sure how to set it up to do the adjustment on the solid lifters on my 315 D500 hemi. The last time I adjust solid lifters I was about 12 and it was the family 55 Dodge Regent flat head six and I had small hands and could get in there. That would be about 1963. Then the next time was 1985 on my Volkswagen Jetta after I installed the latest greatest G60 camshaft and that was shims between the overhead cam and the solid bucket lifters. So my now at 66 in 2017, it's been awhile. But I know I can do it. Just not sure exactly how.

Without doing any reading or investigation, I would have started with removing the distributor cap and rotating the engine until the rotor came to No. 1 and then confirming with a small clean wooden dowel done the spark plug hole and rocking the engine on the crank bold (1.25" socket) to make sure I was at TDC. Then I would be confident that the No. 1 valves were both closed and I could adjust them (0.012 = hot intake/0.014 cold; 0.022 = hot exhaust/0.024 cold). And so on.

Then I decided to contact our local old hemi expert, Norm Frey. I ended up talking to his son, Mile Frey at Knight Bridge Service Ltd. He kind of laughed at me because he, after doing countless numbers of these, can do it blindfolded. Nevertheless, he gave me clear instructions:

Line up the firing order, 1-8-4-3-6-5-7-2, in two rows:

1 - 8 - 4 - 3
6 - 5 - 7 - 2

"Get the engine positioned so the No. 1 intake is just rocking and then adjust No. 6 valves, then 8 and adjust 6 and then 4 and adjust 7, and so on"

Me: Deer in the headlights "Okay, thanks". (I didn't understand it but I knew that I would figure it out - eventually)

So since then I have been trying to do the math in my head why the above instructions would work. Fell asleep a few nights trying to figure it out mentally, without the benefit of a visual aid. Finally this rainy morning, I sat down with paper and pen and tried to map it out. After the first round (720 degrees of rotation) on Number 1, I realized that the pattern on the other cylinders would be the same. At that point, I sat down at the computer and got Excel fired up. The result is the creation below based on Mike Frey's instructions.

They instructions work!! Whenever the intake valve is rocking between closed and open at the end of the exhaust stroke and the start of the intake stroke, the corresponding cylinder, i.e. 6 for 1, is at the end of the compression stroke and the start of the power stroke, i.e. in the middle of the 180 degree zone when the valves are closed and ready for adjustment of the rockers. I have diagrammed this for all eight cylinders and high lit the intake valve rocking position and the corresponding optimal zones. The reverse also works, i.e. get No. 6 intake rocking and No. 1 is optimal for valve adjustment

This won't be news to many of you. However, now that I have figured it out, I have to share what I have learned and created.

Hope you can see it. I had to print it and then scan it before posting to the FL forum. If anybody wants a full sized version, let me know.

Or not.



Edited by 56D500boy 2017-06-08 7:50 PM




(DForgiesDodgeV8ValveAdjustmentWindow.JPG)



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56D500boy
Posted 2017-06-09 2:02 PM (#541865 - in reply to #541816)
Subject: RE: One way to determine piston position for valve adjustments



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Location: Lower Mainland BC
I've been waiting for somebody to:

a) spot the error omission on Cylinder No.4 and 180 degrees (I missed the notation that the exhaust valve would be closed "C")

b) that another way at looking at the diagram would be:

When Cylinder 1 is at TDC, Cylinder 8 is halfway into its compression stroke and cylinder 2 is halfway through it's power stroke and could be adjusted

When Cylinder 2 is at TDC, Cylinder No. 1 is halfway through its compression stroke and Cylinder 7 is halfway through its power stroke and could be adjusted

When Cylinder 3 is at its TDC, Cylinder 4 is halfway through its power stroke and cylinder 6 is halfway through its compression stroke and could be adjusted

When Cylinder 4 is that TDC, Cylinder 3 is halfway through is compression stroke and cylinder 8 is halfway through its power stroke and could be adjusted

5 at TDC = 6 halfway through power and 7 halfway through compression

6 at TDC = 5 halfway through compression and 3 halfway through power

7 at TDC = 2 halfway compression and 5 halfway power

8 at TDC = 4 halfway compression and 1 halfway power

More than one way to "skin a proverbial (not literal) cat".

Now I just have to get out there and do it.

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57chizler
Posted 2017-06-09 2:32 PM (#541867 - in reply to #541816)
Subject: RE: One way to determine piston position for valve adjustments



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Mopar has offered this decal for years; works on any engine with the 1-8-4-3-6-5-7-2 firing order.



(valvelash.jpg)



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56D500boy
Posted 2017-06-09 4:17 PM (#541869 - in reply to #541867)
Subject: RE: One way to determine piston position for valve adjustments



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57chizler - 2017-06-09 2:32 PM
Mopar has offered this decal for years; works on any engine with the 1-8-4-3-6-5-7-2 firing order.


Thanks. I have never seen that decal before. Even if I had, I would still have to have gone through the same exercise as I did above.

From my chart No. 1 at TDC = 2 at halfway in the Powerstroke and 8 halfway in the compression stroke. Not sure why the decal doesn't allow both No. 2 and both No. 8 valves to be adjusted at the same time.

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56D500boy
Posted 2017-06-10 1:51 AM (#541887 - in reply to #541869)
Subject: RE: One way to determine piston position for valve adjustments



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Location: Lower Mainland BC
Today, I went with a TDC method, using a piece of dowel to give me a visual indicator of TDC as I rotated the engine with a 1.25" deep socket and my ratcheting torque wrench. I've done 1, 8 and 4 and had to quit for the day (to cook some ribs au BBQ). I had problems with No. 8 intake. It seems that the more I cranked the adjuster out, the less clearance I had - very strange. I decided to come back to it after I do the other ones. For adjusting I am using a 3/8" stubby rachet, a 3" extension and a 7/16" socket. I plan to go around them all twice because I am sure my "feel" on the feeler gauge will improve with practice. I might use a long thin screw driver instead of the dowel tomorrow.

I don't know why the TDC method isn't promoted as the best method, maybe it doesn't work on a non-hemi???




Edited by 56D500boy 2017-06-10 2:42 PM
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57chizler
Posted 2017-06-10 1:54 PM (#541899 - in reply to #541869)
Subject: RE: One way to determine piston position for valve adjustments



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56D500boy - 2017-06-09 1:17 PM
Not sure why the decal doesn't allow both No. 2 and both No. 8 valves to be adjusted at the same time.


The earliest version of the Mopar chart had you turn the crank 180° at a time and adjust 4 valves in each position but the latest version is more precise....positions the lifter at the heel of the cam lobe.

If you have the intake manifold removed when using the chart, you can see the actual lifter contact on the lobe at each position.
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56D500boy
Posted 2017-06-10 2:46 PM (#541900 - in reply to #541899)
Subject: RE: One way to determine piston position for valve adjustments



Expert 5K+

Posts: 9855
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Location: Lower Mainland BC
57chizler - 2017-06-10 1:54 PM
The earliest version of the Mopar chart had you turn the crank 180° at a time and adjust 4 valves in each position but the latest version is more precise....positions the lifter at the heel of the cam lobe.
If you have the intake manifold removed when using the chart, you can see the actual lifter contact on the lobe at each position.


Maybe it's an early hemi thing (and maybe just the 56 D500 with the solid lifters thing), but since I had to remove the spark plugs to remove the 315 hemi valve covers, I am not sure why TDC (for each cylinder) isn't also precise. Both the valves have to be fully closed at the end of the compression stroke and start of power stroke. Seems like a good time to adjust them.

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57chizler
Posted 2017-06-13 1:50 PM (#542046 - in reply to #541900)
Subject: RE: One way to determine piston position for valve adjustments



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Location: NorCal

Again, with the cam/lifter interface in view, you can see that at TDC on a particular cylinder the lifter is not on the center of the lobe base circle. This is the desired location for adjustments.



(Cam Lobe.jpg)



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