Adjusting Stud Mount Rockers - and checking pushrod length

[Guest]

[mighty mouse]

Adjusting Valvetrain

    This is the system I use when adjusting stud mount roller rockers on my small block Fords with an Hydraulic Roller Camshaft.  This will also work for almost any engine using adjustable roller rockers* and a hydraulic style cam and lifter combination (roller or not).  My particular Roller Rocker Arms on my 351w with World Products Windsor Heads are Trick Flow 51400520 - 1.6 ratio for a 7/16" stud.  

1. Remove the valve covers, and pick a cylinder you are going to set the preload on. I think the easiest and fastest way is to just follow the firing order.  For the 5.0 HO and 351w the firing order is 1-3-7-2-6-5-4-8.  Start with the No. 1 cylinder (passenger side front).

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.  You are now ready to adjust that cylinder's intake rocker arm.

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.

4. Now pull up and down (or rotate) the intake pushrod with your fingers while tightening down the rocker arm. When you feel a slight resistance to the movement of the pushrod, you are at "Zero Lash". Turn the adjusting nut down one quarter to one half turn from that point. Lock the adjuster into position. The intake is now adjusted properly.

Wrench/Nut Turning ⅛ - ¼ - ½

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. 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.

   *If you are using a bolt down pedestal type rocker, or using a mechanical camshaft, consult a Chiltons/Haynes or other manual for guidance, as this procedure works only on valvetrains using adjustable stud mount rocker arms and hydraulic lifters.

Nathan Moonen                     
Moonenn3186@hotmail.com

[5.0 falcon]

Could you explain how pushrod length fits into the equation?

[Joel5.0]

PR length allows setting of the valvetrain geometry, by changing its length , it will affect the "sweep" pattern, location with respect to the the valve stem, or its contact pattern through the valve open-close cycle. This has an effect on valvetrain, wear and tear. 

To check your pushrod length you will need a pushrod length checker (make one or buy one) and some light duty checking springs.  Install the light duty checking springs onto your cylinder heads and then install the adjustable pushrod into the pushrod slot making sure that it seats in the lifter.  Mark the valve stem tip with a sharpie or other dye and set your rocker arm following the instructions above for adjusting your stud mount rockers (or pedestal rockers if that is your bag).  Once the rocker arm is set, roll the engine over by hand several times and remove the rocker arm.  Then check your wear pattern.  Adjust according to the guide pictures below.

Too short = towards intake side

Centered and narrow = optimum

Too long = towards exhaust side


Now.......

Could you explain how pushrod length fits into the equation?

PR length has to be set/determined providing for the lifters preload....or the additional .020" - .060" needed for it.....

NOTE:
You also need a HR lifter made into a solid lifter, the following will help you make two of them for the Geometry Check.

Or make you own checking solid lifters......I have two I prepared following the procedure below.

Need a solid roller lifter to check piston-to-valve clearance on your hydraulic roller cammed 5.0L or 5.8L Ford?

Save a couple bucks and make your own out of an old stock lifter. The lifter at left (below) is a disassembled stocker. To turn it into a checking lifter, you trash the spring and flip the main plunger 180 degrees until your lifter looks like the one in the center.



The lifter on the right (above) is the finished product, marked with a yellow band so it won't get mixed up with its hydraulic cousins.

Do It Yourself Checking Roller Lifter

So you want to check piston-to-valve clearance on your hydraulic roller cammed small block Ford, but don't have the cash for an expensive solid checking lifter? Then do what hot rodders have always done: make your own. It's actually pretty simple: just take the lifter apart, grind .020 in. off the main plunger, remove the spring, flip the main plunger around, and reassemble. Presto -- a solid checking lifter.

Courtesy of http://www.trickflow.com/articles/stroker_1/#

Added: and to clarify some questions.....
You could also flip the plunger and not grind the .020" off, the snap ring will be a little difficult to install but it will work. If you intend to use the lifter in your build, disassemble it, flip the main plunger to its original position, reinstall the spring and reassemble the lifter. That's how I prepared the 4 lifters I have for degreeing cams, checking valvetrain geometry and PtV.

[5.0 falcon]

Killer pics Joel. Thanks.

[Nacho]

...

[wldtang]

Excellent write up. I need to modify a hyd. lifter with the correct preload so it will not change when checking for correct P rod length. I was taught that you could take a marker and mark the top of the valve stem. Rotate the motor over and check the wear of the rocker roller tip on the valve stem. This will show you where you p rod length is.

[trickcat]

 

[CrimsonGT]

this thread really opened y eyes and helped me understand alot better than before.
nice pics 

[gator]

I have a ?, when you use this method for adjusting the rockers do you need to make sure the cylinder is on the compression stroke or does it matter?

[Joel5.0]

I have a ?, when you use this method for adjusting the rockers do you need to make sure the cylinder is on the compression stroke or does it matter?

Nope...... you follow the valves cycling.....

....watch the exhaust valve on that particular cylinder. When the exhaust valve begins to open, stop.  You are now ready to adjust that cylinder's intake rocker arm.

Means that cylinder piston is at the "beginning" of the exhaust cycle....you adjust the intake valve rocker.....and..

...watching that same (cylinder) 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.

Means that cylinder piston is at the "end" of the intake cycle..... you adjust the exhaust valve rocker.

[norm]

is there any particular reason to go in the order of the firing order?i use the same method to set mine but i do the drivers side first then the passenger.i don't think there would be any difference other than the running from side to side.i use a starter button also.

[Joel5.0]

Nope...... your call.

[norm]

all- righty

[gator]

Thanks

[irish]

Was reading about a different way of adjusting, TDC for each cylinder and adjust both intake and exhaust at the same time?  Anyone care to elaborate on this in more detail please?

thanks

Matt