Valve lash adjustment for new lifters HELP
10-09-2011, 04:10 AM
#1
Pro
Thread Starter
Valve lash adjustment for new lifters HELP
I bought a Crane Pro-Gold Race Aluminum Roller Rocker Kit LS 1.8 ratio for my LS2 engine. I also bought new LS7 hydraulic lifters, the lifter buckets, head bolts and other needed items.
I'm Dutch so English is not my native language, and although I can manage OK, the installation instructions that came with the kit are not 100 percent clear to me. I'm looking for help explaining a few things.
One of the things is achieving zero lash, and setting the right valve lash.
In the manual from Crane, this one
http://www.cranecams.com/uploads/instructions/561e.pdf
They mention the following:
Do not rotate the crankshaft during the remaining procedure.
1. Tighten each rocker arm adjusting nut ¼ turn.
2. Allow the lifters to bleed down for 10 minutes. This is necessary for “in the car” installation, when the lifters have oil in them. The
lifter will remain in a partial pumped up state, even after the engine is disassembled. When using new lifters, no waiting is necessary.
3. Repeat this procedure seven more times for a total of two full turns. This will provide a lifter preload of approximately .082.
Extensive testing has shown this preload adjustment to provide the best power and performance, as well as, minimizing valve train
noise. Be sure to allow 10 minutes bleed down time after each ¼ turn to insure there will be no valve to piston contact. The lifters now
have the proper preload.
4. While holding the adjusting nut with a wrench, carefully tighten the setscrew in the adjusting nut of each rocker arm. Rotate the two
tools simultaneously, clockwise to lock the setscrew and adjusting nut together. Allow another 30 minutes bleed down time after this
final setting, when new lifters are not installed.
5. Now is a good time to take a compression test. If a cylinder checks low, a rocker adjustment is probably too tight. Repeat the
adjustment procedure on the affected cylinder, and then recheck compression.
In step 2 it says to repeat the procedure seven more times, am I correct that they mean the same procedure for the remaining 7 cylinders, or do they mean seven more times for the same cylinder.
In step 4 it says Rotate the two tools simultaneously clockwise to lock the setscrew. Shouldn't you not just turn the set(hex) screw in the polylock nut to lock them together.
And what is the needed torque for the hex screw when you lock it. And the right torque for new GM head bolts.
Tips are very welcome
Fred
I'm Dutch so English is not my native language, and although I can manage OK, the installation instructions that came with the kit are not 100 percent clear to me. I'm looking for help explaining a few things.
One of the things is achieving zero lash, and setting the right valve lash.
In the manual from Crane, this one
http://www.cranecams.com/uploads/instructions/561e.pdf
They mention the following:
Do not rotate the crankshaft during the remaining procedure.
1. Tighten each rocker arm adjusting nut ¼ turn.
2. Allow the lifters to bleed down for 10 minutes. This is necessary for “in the car” installation, when the lifters have oil in them. The
lifter will remain in a partial pumped up state, even after the engine is disassembled. When using new lifters, no waiting is necessary.
3. Repeat this procedure seven more times for a total of two full turns. This will provide a lifter preload of approximately .082.
Extensive testing has shown this preload adjustment to provide the best power and performance, as well as, minimizing valve train
noise. Be sure to allow 10 minutes bleed down time after each ¼ turn to insure there will be no valve to piston contact. The lifters now
have the proper preload.
4. While holding the adjusting nut with a wrench, carefully tighten the setscrew in the adjusting nut of each rocker arm. Rotate the two
tools simultaneously, clockwise to lock the setscrew and adjusting nut together. Allow another 30 minutes bleed down time after this
final setting, when new lifters are not installed.
5. Now is a good time to take a compression test. If a cylinder checks low, a rocker adjustment is probably too tight. Repeat the
adjustment procedure on the affected cylinder, and then recheck compression.
In step 2 it says to repeat the procedure seven more times, am I correct that they mean the same procedure for the remaining 7 cylinders, or do they mean seven more times for the same cylinder.
In step 4 it says Rotate the two tools simultaneously clockwise to lock the setscrew. Shouldn't you not just turn the set(hex) screw in the polylock nut to lock them together.
And what is the needed torque for the hex screw when you lock it. And the right torque for new GM head bolts.
Tips are very welcome
Fred
10-22-2011, 10:38 AM
#3
Safety Car
From what I am reading, no,
2. Allow the lifters to bleed down for 10 minutes. This is necessary for “in the car” installation, when the lifters have oil in them. The
lifter will remain in a partial pumped up state, even after the engine is disassembled. When using new lifters, no waiting is necessary.
Your post says you are using new lifters.
3. Repeat this procedure seven more times for a total of two full turns. This is PER ROCKER ARM This will provide a lifter preload of approximately .082.
Extensive testing has shown this preload adjustment to provide the best power and performance, as well as, minimizing valve train
noise. Be sure to allow 10 minutes bleed down time after each ¼ turn to insure there will be no valve to piston contact. The lifters now
have the proper preload
What it's saying is to tighten each rocker a 1/4 turn, after the initial freeplay is removed, a total of 8 times for each rocker arm, for a total of 2 turns for each rocker arm. This is to set lifter preload.
I do it the old fashioned way. Bring up each rocker until the valve is closed, remove the freeplay, then I turn the pushrod by hand until there is a slight drag when twisting the pushrod and then tighten 1 1/2 turns and then set the lock screw.
When setting the lock screw, hold the hex nut and tighten the set screw.
Some reading enjoyment
http://www.carcraft.com/howto/ccrp_0...aft/index.html
http://www.compcams.com/Instructions/Files/151.pdf
2. Allow the lifters to bleed down for 10 minutes. This is necessary for “in the car” installation, when the lifters have oil in them. The
lifter will remain in a partial pumped up state, even after the engine is disassembled. When using new lifters, no waiting is necessary.
Your post says you are using new lifters.
3. Repeat this procedure seven more times for a total of two full turns. This is PER ROCKER ARM This will provide a lifter preload of approximately .082.
Extensive testing has shown this preload adjustment to provide the best power and performance, as well as, minimizing valve train
noise. Be sure to allow 10 minutes bleed down time after each ¼ turn to insure there will be no valve to piston contact. The lifters now
have the proper preload
What it's saying is to tighten each rocker a 1/4 turn, after the initial freeplay is removed, a total of 8 times for each rocker arm, for a total of 2 turns for each rocker arm. This is to set lifter preload.
I do it the old fashioned way. Bring up each rocker until the valve is closed, remove the freeplay, then I turn the pushrod by hand until there is a slight drag when twisting the pushrod and then tighten 1 1/2 turns and then set the lock screw.
When setting the lock screw, hold the hex nut and tighten the set screw.
Some reading enjoyment
http://www.carcraft.com/howto/ccrp_0...aft/index.html
http://www.compcams.com/Instructions/Files/151.pdf
10-22-2011, 12:38 PM
#4
Pro
Thread Starter
Thank you glenB for your explanation, the old fashioned way of doing it saves a lot of time. I did think the "two full turns" was for all the rockers, thank you for this tip. I wonder what Crane thinks of the old fashioned way, it certainly saves time and is easier to understand for simpletons like me.
