[glhs#116]

Originally Posted by 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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I will certainly revisit the preload but none of them were bottomed out and the car runs and drives normally.

As far as the sequence, it's one Cliff posted somewhere. If you are at compression TDC for #1 then both its rockers are at base circle on the cam. You can adjust those. Then rotate engine 90 degrees and do the same for the next cylinder in the firing sequence. In two full rotations you have done all the valves on the base circles..

Sam

[glhs#116]

Originally Posted by glhs#116

I will certainly revisit the preload but none of them were bottomed out and the car runs and drives normally.

Sam

Well, therein lies a tale..

I did indeed revisit the valve lash. I backed them all out and set them at 1 1/4 preload on a slightly warmed up engine. I then decided that while the roads are quiet (it's a national holiday at the moment) to take a drive just twenty minutes on the highway just to complete cam break-in and get a feel for things.

Well, the trip down was uneventful. On the turnaround I floored it in second and it felt a bit soft. I went into third and something didn't sound right. I backed off and now I had a loud tick or rattle. I slowed down to about 50mph or so and cruised gently to the next junction. It was getting louder. I was thinking, "Crap! But at least I am finding out what it is. Feels like something bad."

I found a little turn off that used to lead to the Emir's old old palace but is now mostly unused.



I popped the bonnet and heard loud clatter from the passenger side. Shut it down. I pulled that valve cover thinking I would find a busted rocker arm or something. Everything looked fairly normal under the valve cover though. I honestly thought, God didn't bring me this far to have the car ruined on one drive after all this care. Anyway, I start wiggling and find a loose pushrod. I wondered if a cam lobe could go off that far that quickly. I tightened it down to snug which took a few turns. Then I found another. I snugged that. I ran the car briefly (making a huge mess on that side with the valve cover off) just to see if anything looked odd or felt odd on the rockers and if the sound was still there.

About this time the penny dropped. I had adjusted the valves but not locked the lock nuts! Doh! So I took off the other valve cover and in the heat of the desert day with not a hint of shade adjusted all the rockers once more to 1 1/4 turn preload and LOCKED the lock nuts and SNUGGED the nuts against the tightened lock nuts. The drive home was uneventful after that.

I still have the same tick. But otherwise the car sounds smooth and runs well except that it won't take much timing and it likes to diesel on after shutdown about half the time. It also seems to run hot a bit easier but the retarded timing is enough to explain that. I will try to find some cooler range plugs and see. The tick also goes away by 1500rpm and can't really be heard after that. Although it is pretty noticeable at idle and lower engine speeds.

Sam