Roller Rocker installation
- Thread starter Ray@VSK
- Start date
Michael Yount
Mustang Master
Doesn't sound like you used the proper procedure.
Rotate the engine until the lifter for the rocker you're installing is on the base circle of the cam (valve closed). Then hand tighten the rocker until zero lash is achieved (no gap on the valve stem end or the pushrod end). Once at zero lash, put your torque wrench on and torque to 18-20 ft-lbs. while counting the number of turns on the bolt. It should hit the torque between 1/4 turn and 1 turn. If it takes more than 1 turn, use shims (.030" increments) to raise the rocker - each .030" will reduce the number of turns by about 1/4. If it hits the torque before a 1/4 turn (you probably won't be able to hand tighten to zero lash) then you'll either need to remove a small amount of material evenly from the bottom of the fulcrum, or get longer pushrods. You shouldn't have to worry about the last situation unless you've had the heads cut, the block cut or are using an aftermarket cam. Even cams supposedly cut on a stock base circle come up short every once in a while.
What do you mean by rotating the engine til the rocker's 'level'?
Rotate the engine until the lifter for the rocker you're installing is on the base circle of the cam (valve closed). Then hand tighten the rocker until zero lash is achieved (no gap on the valve stem end or the pushrod end). Once at zero lash, put your torque wrench on and torque to 18-20 ft-lbs. while counting the number of turns on the bolt. It should hit the torque between 1/4 turn and 1 turn. If it takes more than 1 turn, use shims (.030" increments) to raise the rocker - each .030" will reduce the number of turns by about 1/4. If it hits the torque before a 1/4 turn (you probably won't be able to hand tighten to zero lash) then you'll either need to remove a small amount of material evenly from the bottom of the fulcrum, or get longer pushrods. You shouldn't have to worry about the last situation unless you've had the heads cut, the block cut or are using an aftermarket cam. Even cams supposedly cut on a stock base circle come up short every once in a while.
What do you mean by rotating the engine til the rocker's 'level'?
Michael Yount
Mustang Master
By the way, other than a custom cam and a ProM meter, your set up and mine are VERY similar; I've installed/adjusted mine several times, so lots of experience with this on rockers/heads like yours. Mine are nearly as quiet as the stockers. After you use the correct procedure, you may have to go back once the engine is warm, and redo the install with the components hot. I have to do that each time with mine to quiet down one or two of the rockers.
Michael Yount
Mustang Master
What do you mean by "rotate the motor til both are equal"? You mean till both pushrods are completely 'down' and equal in height? If so, that means both lifters were on the base circle of the cam.
You didn't mention counting turns - how many times did the bolts turn when you hit the torque? On mine, 11 of them required no shims, 4 of them required 1 .030" shim, and 1 required a .060" shim.
You didn't mention counting turns - how many times did the bolts turn when you hit the torque? On mine, 11 of them required no shims, 4 of them required 1 .030" shim, and 1 required a .060" shim.
04sleeper
Founding Member
Base circle of the cam means not on a lobe. Meaning no lift or refered to as "Zero Lash". You can do 2 rockers at a time. The intake and exhaust for 1 cylinder at a time.Ray@VSK said:
As you are looking at the motor from the side the Exhaust valve will open then close and then the Intake valve will open and then close as you are turning the motor over. Make sure you rotate the motor a little past the closing of the Intake valve to make sure that it is at "Zero Lash".
Then you can set both the Intake and Exhaust rockers for that cylinder.
That's what I did, I turned em down till I got snug then I turned the motor till both rockers were sitting level & torqued, I did note turn to torque it was about 1/3 turn on all of them, should I have tightened em down till I got to the point of torqueing then turned the motor till rockers were set right, then torque ?
Michael Yount
Mustang Master
Ray - you keep saying you're doing it like we say, but you're describing it like this "I turned em down till I got snug then I turned the motor till both rockers were sitting level & torqued" -- that is NOT the procedure that 89sleeper and I are describing.
Once again - rotate the engine until both lifters for a given cylinder are on the base circle of the cam -- that is, until both pushrods are level, and the lifters are on the base circle. If you're not sure how to achieve that, you should snag a friend that knows what they're doing to assist you so you know if you're judging that correctly. Once you've got both lifters on the base circle (in other words, both valves would be closed), put both rockers on and hand tighten the bolts until you achieve zero lash. Zero lash is reached this way - with your left hand, rock the rocker between the valve stem and the pushrod; with your right hand begin to tighten the bolt; as you tighten, the gaps between rocker and valve/pushrod will grow progressively smaller; keep tightening until the gap has just barely gone away - there's no gap on the valve stem side or the pushrod side. That's the 'zero lash' point. Once you're there, THEN put your torque wrench on it and turn to 18-20 ft-lbs while counting turns. The torque should hit between 1/4 turns and 1 turn. If it takes more than one turn, shim it so that the torque occurs at less than one turn. If it takes less than 1/4 turn, shave the fulcrum or get a longer pushrod. Once you've done that, crank it up and let it warm completely up. If one or more are still noisy, take it back apart while hot, and go through the exact same procedure again with everything warm. I don't know how to describe it any better than that.
Once again - rotate the engine until both lifters for a given cylinder are on the base circle of the cam -- that is, until both pushrods are level, and the lifters are on the base circle. If you're not sure how to achieve that, you should snag a friend that knows what they're doing to assist you so you know if you're judging that correctly. Once you've got both lifters on the base circle (in other words, both valves would be closed), put both rockers on and hand tighten the bolts until you achieve zero lash. Zero lash is reached this way - with your left hand, rock the rocker between the valve stem and the pushrod; with your right hand begin to tighten the bolt; as you tighten, the gaps between rocker and valve/pushrod will grow progressively smaller; keep tightening until the gap has just barely gone away - there's no gap on the valve stem side or the pushrod side. That's the 'zero lash' point. Once you're there, THEN put your torque wrench on it and turn to 18-20 ft-lbs while counting turns. The torque should hit between 1/4 turns and 1 turn. If it takes more than one turn, shim it so that the torque occurs at less than one turn. If it takes less than 1/4 turn, shave the fulcrum or get a longer pushrod. Once you've done that, crank it up and let it warm completely up. If one or more are still noisy, take it back apart while hot, and go through the exact same procedure again with everything warm. I don't know how to describe it any better than that.
Understood, like I said before, my terminolgy & yours are different but they both meen the same thing because I don't know if you realize it or not but when the pushrods are equal so are the rockers but anyways thanks, I guess I got to just keep going over em & I appreciate you indepthness in trying to explain 
Michael Yount
Mustang Master
Actually Ray - the pushrods are at the same height twice for each cam rotation. Once during overlap -- the intake is just starting to open and the exhaust is about to close; at the point when they're the same height, both valves would be slightly open and you don't want to install the rockers then. The other time they're at the same height is when both lifters are on the base circle of the cam - both valves are closed during the compression stroke - that's when you want to install them. Good luck with it.
Michael Yount
Mustang Master
Nope Ray - the lifter is on the base circle of the cam when the pushrod is at it's minimum height, not maximum height. When the pushrod is at maximum height, the lifter is at the very top of the lobe peak - max lift - valve would be max open. That's definitely when you DON'T want to install.
You want to install the pair when both pushrods are at the same (equal) minimum height - that's when the lifters are on the base circle of the cam. Once you get them there, then you tighten by hand until you get to zero lash - no gap on either end of the rocker. Once you're at zero lash - then you torque and count turns.
I'm getting the feeling that it would be really wise if you could hook up with a buddy that's got experience doing this - with all due respect, the way your questions keep coming back, I get the distinct impression that you're really unclear about the procedure, about what the base circle of the cam is, about what zero lash is. But I'm stickin' with ya here....pm me if you want to talk live by phone. I've got free cell time tonight...
You want to install the pair when both pushrods are at the same (equal) minimum height - that's when the lifters are on the base circle of the cam. Once you get them there, then you tighten by hand until you get to zero lash - no gap on either end of the rocker. Once you're at zero lash - then you torque and count turns.
I'm getting the feeling that it would be really wise if you could hook up with a buddy that's got experience doing this - with all due respect, the way your questions keep coming back, I get the distinct impression that you're really unclear about the procedure, about what the base circle of the cam is, about what zero lash is. But I'm stickin' with ya here....pm me if you want to talk live by phone. I've got free cell time tonight...
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