[HWYSTR455]

Wow, bummer. Couple things that I'm not clear on, so going to ask. You say you started with 1 full turn of preload, and then after that you added another 1 3/4 turn? So the total was 2 3/4 turns? That's way too much if that's the case. As a reference, posted this a few times, the amount of preload for each turn depending on the stud threads:

http://www.johncalliesinc.com/pdf/Ad...licLifters.pdf


b. If your adjuster nut is 7/16 x 20 threads per inch, then divide 1 inch by 20 threads per inch. One complete turn down on a 7/16 by 20 adjuster nut will move .050".
c. Next, divide .050" divide by 4 to calculate the distance for a quarter-turn of the adjuster nut (.050" / 4 = .0125").
d. For a 3/8 x 24 adjuster nut, the calculations are:
1" / 24 TPI = .042" per full turn and .042" / 4 = .0105" per quarter-turn.
e. Use the chart below to determine how many quarter-turns to tighten the adjuster nut after Zero-lash:
Cast Iron block and Cast Iron Head = .020" - .025"
Cast Iron block and Aluminum Head = .030" - .035"
Aluminum block and Aluminum Head = .045" - .050"

HFT lifters generally require @ .030-.060 preload. So, max I would think would not exceed 1 1/4 turns, roughly.

You commented:

"I adjusted the rockers with one turn preload one at a time in firing order turning the engine over by hand 90 degrees each time."

Can you explain that better please? Your process?

EDIT: Keep in mind the extract above is when using Morel HYD Roller Lifters, which call for @ a preload of .020-.025, and for an iron block, with aluminum heads, add .010-.015. So for a HFT lifter, roughly .075 is max.

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