Rocker arm adjustment question

*1bad66* · Post by ***1bad66*** » April 23, 2007, 8:11 pm

My truck has a 351w out of a 71 or 72 LTD. I cant figure out whether it has adjustable or non adjustable rocker arms. The instructions that came with the edelbrock cam said to tighten the rockr arms to zero clearance between the rocker and the pushrod/valve and then put an additional 1/2 turn if they were adjustable and if they were not adjustable tighten them all the way down. I just assumed that they were adjustable and tightened them according to the edelbrock specs. It now runs good but the valves are ticking and I think it might have to do with how I adjusted the rockers. Any help is greatly appreciated. Thanks

blackagatha · Post by **blackagatha** » April 24, 2007, 1:17 am

whaaa???

In my understanding, adjustable rocker means it has a screw adjuster on the pushrod end. A non adjustable is just a solid chunk of Iron (or stamped steel in your case I guess).

jakdad · Post by **jakdad** » April 24, 2007, 7:36 am

blackagatha wrote:whaaa???

In my understanding, adjustable rocker means it has a screw adjuster on the pushrod end. A non adjustable is just a solid chunk of Iron (or stamped steel in your case I guess).

That's on FEs and Y-Blocks. Windsors have adjustment on the rocker stud.
To answer the question, Follow Cranes insructions to the letter. Go back through them again, see if that gets it.

*1bad66* · Post by ***1bad66*** » April 24, 2007, 3:06 pm

Thanks for the replies. My cam was not from crane. It is a edelbrock performer. I have read through the instructions several times and all it says is to tighten them all the way if they are non-adjustable or just a half of a turn past zero clearance if they were adjustable. Thanks for any help

ripsnorter · Post by **ripsnorter** » April 24, 2007, 5:10 pm

My understanding is that "adjustable" means solid lifters which will have a second nut on the rocker arm stud, or screw, or some way of holding the nut in place once you've tightened it down.

"non-adjustable" just means a hydraulic lifter set which will only have 1 nut on it with no set screw/second nut.

*1bad66* · Post by ***1bad66*** » April 24, 2007, 5:31 pm

They only have 1 nut for each rocker and it does have hydraulic lifters. It sounds like they are non adjustable. Thanks for the help

jakdad · Post by **jakdad** » April 24, 2007, 8:51 pm

Please let me clarify. Go into the Crane site and use their instructions on initial adjustments. Usually you're ready to run after that.

blackagatha · Post by **blackagatha** » April 24, 2007, 10:49 pm

oh... good to know... thx.

Fanatic · Post by **Fanatic** » April 25, 2007, 8:07 pm

The easiest way to tell if they are adjustable is to remove a rocker arm and look at the stud. there will be a shoulder below the threads if they were meant to be just tightened down. (non-adjustable) If it just looks like a threaded rod then they are adjustable. All of the older books say to tighten 3/4 turn after zero clearance, but anyway----
*make sure that the cylinder is on top dead center...both valves closed
*spin pushrod with fingers on one hand until you can no longer turn pushrod
*tighten rocker arm nut 3/4 turn from this point

each cylinder must be done one at a time when each is at TDC

this will get you going and should be GREAT but if you are concerned you can get it running this way and then go over each rocker while it is running and loosen until tapping is heard and then retighten 3/4 turn.
This should not be necessary if you take your time using the first method

Tim

*1bad66* · Post by ***1bad66*** » April 25, 2007, 8:16 pm

Thanks guys I think I will try it again this weekend if I get time.

jakdad · Post by **jakdad** » April 26, 2007, 4:25 am

Here is a copy of the Crane instructions. Works great. This is for hydraulics.

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 that 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.

Do Hydraulic Lifters Need to be Primed with Oil?

Many people mistakenly believe that hydraulic lifters must be soaked in oil overnight and be hand pumped up with a pushrod before installing into a new engine, however this is not necessary. In fact, this could cause the lifter to act as a "solid" and prevent obtaining proper preload. What is very necessary is the priming of the entire engine's oil system before starting up a new engine for the first time. This is done by turning the oil pump with a drill motor to force oil throughout the entire engine. Crane Cams offers oil pump primers for Chevrolet and Ford engines.

Truckfarmer · Post by **Truckfarmer** » April 27, 2007, 8:10 am

Every small block Ford I ever had used a torque setting to adjust the valves. You torque the rocker arm to the correct amount. Then you rotate the crankshaft 90* and torque all of them again. Rotate 90*, retorque, rotate 90* for the last time and retorque again.
What does the Chilton's manual say?

jakdad · Post by **jakdad** » April 27, 2007, 9:45 am

Truckfarmer wrote:Every small block Ford I ever had used a torque setting to adjust the valves. You torque the rocker arm to the correct amount. Then you rotate the crankshaft 90* and torque all of them again. Rotate 90*, retorque, rotate 90* for the last time and retorque again.
What does the Chilton's manual say?

You are correct. Those are the settings for non adjustable valve train with press in studs.