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Just an update this tool was 50 bucks an absolute monster to see when it arrived. Never used one but on my first one I remembered vaguely a mechanic holding the rear with one hand on the valve and learned the way to pivot it onto the head so I don't scratch the shiny-ness(machined surface for you motorheads). Are these offset keepers with the .250 shown? I question my machine shops trustworthiness charging me good amount for these that I supposedly needed well back to having fun. Have to add I measured one exhaust valve it was 4.882 and than an exhaust valve that measured 4.813 should I investigate more?
Last edited by Guy with a Chevy; Feb 14, 2023 at 10:52 AM.
looks like it to me. doubt they will be any taller than normal, its the locking groove thats shifted 'up' in this case. normally its in the center. that should give you less spring installed height.
id be cautious about valvetrain geometry if your machine shop is moving things around on you. did they say why they needed the offset keepers?
He said with regular ones the spring retainer if that's what the circle cap is called would hit the rocker and the locks would come loose said had to be done because the valves had been machined so much. Some were machined more than others when I checked myself so it adds up thankyou for letting me know
Those are 100% a -0.050" lock (PAC-L8116)
A standard lock will have 0.205" from top of groove to bottom (PAC-L8113)
and a +0.050" lock will be 0.155" (PAC-L8114)
I would like to see what that lock looks like in the retainer (assembled on the valve from multiple angles). The through hole on the retainer looks awfully large to me.
ok so you cant just go swapping stuff like that around.
if you do a valve job on a ls head and remove enough material, or when you are installing 2" valves in 5.3 heads you have to set the height correctly. the valve ends up deeper in the head which in turn puts the tip where the rocker actuates higher up. this can mess up your rocker geometry since ls valve train isnt adjustable. a different length pushrod could solve it but *might* not.
you also need to check your springs for seat pressure, open pressure and coil bind. the primary reason ive shuffled lock heights around in the past was to tweak spring pressures.
none if this is something you should do without having some knowledge of the larger system.
I didn't change the locks out the machine shop did so they would sit at 1.8 inches closed. With a straight edge on them they were perfectly level. I didn't change anything by swapping the springs
Trendsetter is right. You can't just move the retainer up so you attain the correct installed height. Besides, when the valves are sunk into the combustion chamber deeper, you want to (effectively, by shimming the spring to obtain the correct installed height) move the retainer back DOWN to proper height, not up, because the valve job has already moved the retainer up. If the spring load was correct before at 1.800, getting different, offset keepers SHOULD correct the pressure back to where it was before. But you really need to check seat pressure. My .02
Last edited by grinder11; Feb 17, 2023 at 03:35 PM.
Ok do you have any reasonable doubt why the machine shop would have assembled them with lesser springs and told me to run them? Again all I did was change the springs to BTR beehive.570 lift. I'm not sure how the geometry can be altered if the installed height is 1.800 after installation what am I missing here? I think you guys are missing the machine shop did the work and when you trim one side of the valve the other side must get the same treatment to maintain original install height. These amounts are supposed to be so minimal that you usually don't have to switch out the locks from what I have gathered or am I wrong? With the springs installed the springs all sat at 1.800 and even with the straight edge on top of the valves they were all level I stated this above just not sure what's wrong here
Last edited by Guy with a Chevy; Feb 15, 2023 at 01:11 PM.
Ok do you have any reasonable doubt why the machine shop would have assembled them with lesser springs and told me to run them? Again all I did was change the springs to BTR beehive.570 lift. I'm not sure how the geometry can be altered if the installed height is 1.800 after installation what am I missing here? I think you guys are missing the machine shop did the work and when you trim one side of the valve the other side must get the same treatment to maintain original install height. These amounts are supposed to be so minimal that you usually don't have to switch out the locks from what I have gathered or am I wrong? With the springs installed the springs all sat at 1.800 and even with the straight edge on top of the valves they were all level I stated this above just not sure what's wrong here
I was just trying to say that if the valves are sunk deeper, you can shim the springs, OR use offset locks. Guess the old adage "more ways than one to skin the cats ***" comes to mind here. I get paranoid sometimes on some engine parts. Example: the old locks seemingly had no defects, i.e. there were no dropped valves. By using 16 new, different locks, it's possible to get one that may have a material defect. **** happens. Likely? No. Possible? Yes. The old ones didn't have any defects. Nothing succeeds like success. I cant help feel like that on something like this (and spring retainers, too!), the old ones didnt wear out. So if it were me, Id shim the springs. Back to the cats ***, lol!!
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Are these offset valve locks? 
