Adjustable rockers
Thread Starter
|
Senior User
Joined: Aug 2004
Posts: 150
Likes: 1
From: Rio Vista, California
Adjustable rockers
What is the correct length of pushrods for using adjustable rockers on a stock 360? Does 9.157 sound correct for a ball and cup style? Should they be solid or hollow?
I am using these because the remanu. heads I got from Autozone have the exhaust valves .085 shorter than the intake valves when I put a straight edge across the top of all the valve stems. I bled down all the lifters and got consistent measurements for all exhausts (0.215) and intakes (0.130). The rockers are made by Federal Mogul and were in an engine approx 3 months.
Finally, what is the correct adjustment for this setup?
Thanks.
I am using these because the remanu. heads I got from Autozone have the exhaust valves .085 shorter than the intake valves when I put a straight edge across the top of all the valve stems. I bled down all the lifters and got consistent measurements for all exhausts (0.215) and intakes (0.130). The rockers are made by Federal Mogul and were in an engine approx 3 months.
Finally, what is the correct adjustment for this setup?
Thanks.
Post Fiend
Joined: Jan 2003
Posts: 8,600
Likes: 4
From: Iowa
First, theres only one length of pushrod for the adjustables for hydraulic lifters, AFAIK. That is 9.157". They can be hollow or solid, it doesn't matter. Nothing goes through 'em anyway.
The adjustment proceedure is as follows:
First, turn 'em all out so the pushrod turns freely. You should feel NO scratchiness or catching as you turn the pushrod. Next, turn the adjuster screw in a little at a time until you feel the pushrod start to catch while you turn it. This means all the slack has been taken up. Next, turn the adjuster screw in 3/4 of a turn. That ones done. Do it 15 more times.
The adjustment proceedure is as follows:
First, turn 'em all out so the pushrod turns freely. You should feel NO scratchiness or catching as you turn the pushrod. Next, turn the adjuster screw in a little at a time until you feel the pushrod start to catch while you turn it. This means all the slack has been taken up. Next, turn the adjuster screw in 3/4 of a turn. That ones done. Do it 15 more times.
Postmaster
Joined: Nov 2002
Posts: 3,447
Likes: 1
From: Littleton, CO
Originally Posted by rusty70f100
The adjustment proceedure is as follows:
First, turn 'em all out so the pushrod turns freely. You should feel NO scratchiness or catching as you turn the pushrod. Next, turn the adjuster screw in a little at a time until you feel the pushrod start to catch while you turn it. This means all the slack has been taken up. Next, turn the adjuster screw in 3/4 of a turn. That ones done. Do it 15 more times.
First, turn 'em all out so the pushrod turns freely. You should feel NO scratchiness or catching as you turn the pushrod. Next, turn the adjuster screw in a little at a time until you feel the pushrod start to catch while you turn it. This means all the slack has been taken up. Next, turn the adjuster screw in 3/4 of a turn. That ones done. Do it 15 more times.
My proceedure involves bringing each cylinder to TDC, then rocking the rocker back to compress the lifter. Clearance between the rocker and valve top should be .010-.020 when the rocker is pryed back and the lifter is collapsed.
--Mike
Post Fiend
Joined: Sep 2004
Posts: 5,231
Likes: 1
From: Near Fresno, California
From the Crane Cams website -
Hydraulic Lifters Can Be Adjusted at Any Engine Temperature
Since hydraulic lifters can compensate for thermal expansion of the engine, the adjusting can be done with the engine cold; hot adjustment is not necessary.
Adjusting Hydraulic Lifters for Proper Preload
In order to adjust the preload the lifter must be properly located on the base circle or “Heel” of the lobe. At this position the valve is closed and there is no lift taking place. You will need to watch the movement of the valves to determine which lifter is properly positioned for adjusting.
1. Remove the valve covers, and pick a cylinder you are going to set the preload on.
2. Hand rotate the engine in its normal direction of rotation and watch the exhaust valve on that particular cylinder. When the exhaust valve begins to open, stop and adjust that cylinder’s intake rocker arm. (Why? Because when the exhaust valve is just beginning to open, the intake lifter will be on the base circle of the lobe, the correct position for adjusting the intake.)
3. Back off the intake rocker arm adjuster and remove any tension from the pushrod. Wait a minute or two for that hydraulic lifter to return to a neutral position. The spring inside the lifter will move the pushrod seat up against the retaining lock if you give it time to do so. (If you are installing brand new lifters they will be in the neutral position when they come in the box.)
4. Now spin the intake pushrod with your fingers while tightening down the rocker arm. When you feel a slight resistance to the turning of the pushrod, you are at “Zero Lash”. Turn the adjusting nut down one half to one full turn from that point. Lock the adjuster into position. The intake is now adjusted properly.
5. Continue to hand turn the engine, watching that same intake. It will go to full open and then begin to close. When it is almost closed, stop and adjust the exhaust rocker arm on that particular cylinder. (Again, when we see the intake almost closed, we are sure that exhaust lifter is on the base circle of the lobe.) Loosen the exhaust rocker arm and follow the same procedure described before in steps 3 and 4 to adjust this rocker arm.
6. Both valves on this cylinder are now adjusted, and you can move on to your next cylinder and follow the same procedure again.
Hydraulic Lifters Can Be Adjusted at Any Engine Temperature
Since hydraulic lifters can compensate for thermal expansion of the engine, the adjusting can be done with the engine cold; hot adjustment is not necessary.
Adjusting Hydraulic Lifters for Proper Preload
In order to adjust the preload the lifter must be properly located on the base circle or “Heel” of the lobe. At this position the valve is closed and there is no lift taking place. You will need to watch the movement of the valves to determine which lifter is properly positioned for adjusting.
1. Remove the valve covers, and pick a cylinder you are going to set the preload on.
2. Hand rotate the engine in its normal direction of rotation and watch the exhaust valve on that particular cylinder. When the exhaust valve begins to open, stop and adjust that cylinder’s intake rocker arm. (Why? Because when the exhaust valve is just beginning to open, the intake lifter will be on the base circle of the lobe, the correct position for adjusting the intake.)
3. Back off the intake rocker arm adjuster and remove any tension from the pushrod. Wait a minute or two for that hydraulic lifter to return to a neutral position. The spring inside the lifter will move the pushrod seat up against the retaining lock if you give it time to do so. (If you are installing brand new lifters they will be in the neutral position when they come in the box.)
4. Now spin the intake pushrod with your fingers while tightening down the rocker arm. When you feel a slight resistance to the turning of the pushrod, you are at “Zero Lash”. Turn the adjusting nut down one half to one full turn from that point. Lock the adjuster into position. The intake is now adjusted properly.
5. Continue to hand turn the engine, watching that same intake. It will go to full open and then begin to close. When it is almost closed, stop and adjust the exhaust rocker arm on that particular cylinder. (Again, when we see the intake almost closed, we are sure that exhaust lifter is on the base circle of the lobe.) Loosen the exhaust rocker arm and follow the same procedure described before in steps 3 and 4 to adjust this rocker arm.
6. Both valves on this cylinder are now adjusted, and you can move on to your next cylinder and follow the same procedure again.
