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I recently found them to be "all over the place" even with brand new GM nuts. I could "feel" them with a 3/8" drive rachet/socket, and did not actually measure them. Probably south of 24 inch-pounds.
Yes, I recall that there is wide variation, but don't you mean 24 lb-ft rather than 24 lb-in?
I find it easiest to use a 1/2" breaker bar to turn the nuts for valve adjustment. Too short a lever doesn't provide good control when you want to turn the nut just a few degrees.
I measured some awhile back. Used. About 15-24 inch pounds. I measured a set of new ones and I think they measured about 10 ft. lbs. I would have bet they would have been more. The used ones wouldn't hold solid lifter adjustment by the way. The new ones would.
When we were required to use stock stamped steel rocker arms in SCCA in the 60's, I would always add a bit more prevailing torque with a "special Kent Moore" tool. (hammer) New nuts were, as you mention, all over the map when it comes to even torque. Once the critical adjustment was made, there were no problems.
Posi-Locks were legal in this division but I wouldn't even use those things on a lawn mower. Many DNF's and engine failures because of Posi-Locks.
Again, just going by "feel". It "feels" like about 2-3 ft-lbs, (24-36 in-lbs). Requires very little torque to rotate the stud nuts. So little, that it's surprising how they hold fast. I removed Posilocks that Michael refers to, because they were very problematic. The "loose fitting" standard GM nuts miraculously, are very reliable.
Duke, Having just put new studs and nuts on a big block and then removing some from the small block I would say that the old small block ones required more torque all the way out. They are different in shape and were uniformly more resistant to turning than the new BB units IMO.
John
tops of the studs flat so the set screw has a good place to grip. set the lash .003/.004 loose,thighten the set screw, then just turn the posilock to get the proper lash setting. never had one come loose even in the daytona 500
Re: to use "posilocks you must first machine the
clem-----
The step you describe is ABSOLUTELY necessary if "posi-lock" type nuts are used with STOCK GM rocker studs. Otherwise, you absolutely CANNOT use "posi-locks" with these studs without risking virtual certainty of the nuts loosening in operation.
The alternative, though, is to use ARP rocker studs. These studs are pre-machined to provide a perfect bearing surface for the posi-locks. Using the ARP studs is a convenient way to obtain the proper bearing surface. Plus, you get stronger and higher quality studs in the process. The ONLY way to go (as long as the rules for a racing application allow it).
Conversely, and a lesser-known fact, ARP studs should NOT be used with OEM-style, self-locking nuts. ARP specifically recommends against this and I totally agree with them.
ARP studs do require the use of posi-locks. They don't have to be ARP posi-locks, though. ARP does not manufacture OEM-type, self-locking type nuts for rocker arm applications.
It depends on the posi-lock. The ones that are supplied with Comp Cams Pro Magnum Roller rockers fit with no interference, at all, with big block valve covers WITHOUT drippers. I tried them with big block valve covers with drippers, too. They seem to fit ok, but it might be necessary to use 5/16" thick valve cver gaskets.
Some of the other posi-lock nuts (like ARP) are taller than the Comp Cams versions. I don't know if they will fit, or not.
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