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I've searched, PM'ed, etc. and still don't have a complete understanding on how to find my PR length. 99 Transam 5.7. Titan 4 cam, AI 226 heads that have been milled. GM Mls head gasket. When adjusting my comp cam pr to 0 lash, should the rocker be completely resting on the bar? 8.5 turns starts to lift the trunion off the bar. When I torque to 22 ft/lbs, it's only a quarter turn. I'm using morel 5315 lifters. Pic is just showing the rocker laying in the bar. Thanks. Be easy on me. I'm a ls1 newbie.
Not sure what you mean by "starts to lift the trunnion off the bar". The trunnion will be held in place by the bolt head on top and the bar underneath. start on post #13: https://ls1tech.com/forums/generatio...l#post19085422
You don't need to torque to 22 ft/lb until final install.
And trust me, I asked the same questions over and over, got mixed results on the same cylinder, etc. After several days of trying and taking mental breaks, it finally clicked with the help of others on here. You'll get it, just take your time and stop when you get frustrated.
I watched a video on YouTube and the guy adjusted the pr until no rocking with just finger pressure on the rocker arm. At the point of no more clicking, then he installed the bolt. Im thinking when you adjust the pr up until it lifts the trunion, then its like a bridge, the rocker is now resting on the pr and valve stem. Seems at this point, when i finger tighten the bolt it could preload the lifter.
Looks like you have the right idea OP
-cam on base circle for that cylinder
-pick a certain amount of turns of the pushrod and when you tighten the rocker bolt, hopefully you still have some valve tip to rocker arm play. Fine tune with more turns out with the adjustable pushrod until tightening down the rocker bolt gives you exactly zero lash (just to the point that the valve tip to rocker has no clearance but isn't giving you any preload).
-the number of turns of the adjustable pushrod will equate to a base pushrod length (each turn of checker is 0.050")
-to this measurement you now add the amount of preload you want for your lifters
-base pushrod length plus the lifter preload you want = final pushrod length to buy
To confirm everything assuming you have your lifter preload in mind, extend the adjustable pushrod to your final pushrod length value, tighten the rocker bolt very carefully just to get to zero lash.
Then count how many turns of your torque wrench it takes to get to 22 ft lbs from zero lash. So far almost all sources say 1 turn of the rocker bolt is 0.047". Multiply the number of turns by 0.047" and it should be very close to your total pushrod length you found out earlier.
Ok I think you're starting with the adjustable too long. Start at 7.4" or so and work your way up from there. I'd opt for an 8" digital caliper over the turn method to find the length.
That does seem short. I figured you had something like 7.4" previously installed. Whatever you had before, insert one of those and try to determine if you need more/less length. You really need the caliper for accuracy.
05-26-2016, 09:33 PM
Pushrod length again 
