My 71 Duster work in progress

b-body-bob said:
It seems important that the lock nuts are snug all the time or it gets wobbly. FWIW I used 1/4-20 since that's what the all-thread I have on hand is. 1/4x28 might be less wobbly I dunno.
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It's less wobbly, but it's still wobbly. I've got a wrench out the entire time. I keep one locknut tight and only mess with the other, just snugging it with the wrench.

Good luck with the heat. It's gonna be a barn burner here the next couple of days, too.
 
I've got the old deck up except for about 40 nails I've gotta pull. I couldn't take it any more, had to take a break once I got to where I could lay the new wood over it so the dogs can't get underneath the deck.
 
Yeah, I was thinking last night I need to revisit your description (printed it out) and make sure I have the adjusters where they should be to avoid pushrod-on-rocker violence. I forgot about that. They are all showing the whole ball but no threads. 1 thread showing should be 1/16" less pushrod length.
 
b-body-bob said:
Yeah, I was thinking last night I need to revisit your description (printed it out) and make sure I have the adjusters where they should be to avoid pushrod-on-rocker violence. I forgot about that. They are all showing the whole ball but no threads. 1 thread showing should be 1/16" less pushrod length.
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1-1/2 threads would be 1/16". ;)
 
I kind of mapped out what I've got - 7 rockers have less than .035 clearance. Two have less than .025 clearance. Thank goodness for welding wire. I won't know what it looks like opening/closing until I have pushrods.

I'm still not entirely comfortable grinding on them but I'm going to have to.
 
b-body-bob said:
I'm still not entirely comfortable grinding on them but I'm going to have to.
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As long as you don't make any sharp edges around the perimeter of your grinding area, you're fine. Those are very strong rockers; you haven't enough cam to hurt them. If it makes you feel gooder, you can work them after the initial grinding with progressively-finer sandpaper until they feel smooth. If you really want to go mad, feel free to polish the ground area. Ain't no stress risers in a mirror finish.

FYI, the aluminum rockers in my 340 are pretty heavily ground but those grinds are not particularly smooth. They also have a wicked offset, and did I mention they're aluminum? They were used when I installed and ran them, and no issues with a lot more spring pressure on weaker base material. I've seen Harland Sharp aluminum rockers ground right through to the needle-bearing carriers that didn't break.
 
They're all smoothed out already. Had to stop myself from polishing the whole thing.

Used that finger grinder/sander and a die grinder, both with 40 grit.
 
b-body-bob said:
make sure I have the adjusters where they should be to avoid pushrod-on-rocker violence
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Well, I adjusted one of the adjusters to show a couple of threads between the rocker and the ball and that was as far as it would go.

1694087549471.png

Left is about where the ball was when I measured the first time (didn't actually use that one) and the one on the right is wound out 2 threads and that's about it.

I'm thinking somewhere between the two is where I should measure, to allow for pre-load? IOW shorter is better than longer.

This shows how the pushrod is on the ball with the initial zero thread adjuster

1694089272608.png
 
The only concern is that your pushrod cups don't hit the rockers at full lift. Of course, you don't have your final pushrods yet either, since you've only just measured. The cups will almost certainly be a little different, although whether they'll be taller (deeper socket) isn't really likely. Generally the aftermarket go-fast guys will shave a gram wherever they can.

Looking at the photo, I'd say between a one-half and one full thread showing beneath would be ideal, leaving you with enough "turn in" to properly set your preload. You'll want about 3/4 of a turn for that, or ~.031" preload.
 
I adjusted the rocker I had turned all the way out so it only had 1 thread showing, leaving me with an effective length of 7.05.

Have you ever made your own cut-to-fit pushrods? Cup and ball seem pretty rare in odd sizes.
 
b-body-bob said:
I adjusted the rocker I had turned all the way out so it only had 1 thread showing, leaving me with an effective length of 7.05.

Have you ever made your own cut-to-fit pushrods? Cup and ball seem pretty rare in odd sizes.
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I have not. I don't have the patience to press together 16 pushrods.

I ordered mine from Smith Bros, but I've also been told OE Pushrods makes quality custom-length HP pushrods at a considerably lower cost than the Smiths. I will probably try OE for my Six Pack engine. If you're going to order from Smith Bros, don't do it online--you'll end up calling them eventually anyhow. Apparently they don't check their online orders often.

You have a plug for that rocker shaft, right?
 
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