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Discussion Starter · #1 ·
For those in the know, how often should they be re-adjusted for our hydraulic roller system? I don't know if it would differ between brands, so I have the T&D's. TIA
 

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Discussion Starter · #3 ·
They are, but there are a couple of options out there to purchase adjustable rocker arms, rather than having the preload already set.

TTT
 

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JasonGS said:
For those in the know, how often should they be re-adjusted for our hydraulic roller system? I don't know if it would differ between brands, so I have the T&D's. TIA
Since the lifters are hydraulic you should only have to adjust the valve lash once you install the adjustable rockers and they should need no futher adjustments.

Greg
 

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radrace19 said:
Since the lifters are hydraulic you should only have to adjust the valve lash once you install the adjustable rockers and they should need no futher adjustments.

Greg
Yep. :cool:
 

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Discussion Starter · #8 ·
Here you go Lee:

Adjusting Valve Lash with Adjustable Rocker Arms:

First, remove all spark plugs, make sure your rocker arms are not yet installed, but install the pushrods. Removing the spark plugs will make it MUCH easier to turn the engine over throughout the process. You will not need any special tools to adjust valve lash. You will need a 15/16" socket or wrench to turn the engine over (from the harmonic balancer), and the applicable size wrench/allen wrench for the rocker arm adjusting screws. You will also need something long, skinny, and non-abrasive to stick in the spark plug holes to ensure each piston is at TDC (I used a plastic drinking straw).

Start out with the #1 piston at TDC. This is where having a 2nd person helping you will come in handy. You need to turn the engine over in the proper running order (clockwise). First the intake valve will open (pushrod will go up) then close (pushrod will go back down), then the exhaust valve will immediately do the same thing. For the village idiot, the intake valve is on the right, and the exhaust valve is on the left. ;) Once the exhaust valve closes, the piston will be on its way down. Now have someone hold the object in the spark plug hole. It should be held with no pressure, so that it can freely move up/down with little to no pressure. Turn the engine over until the piston comes all the way to the top. The object will come out of the hole, then start going back in the hole after TDC. If it starts going back down, you went too far. Just turn the engine over backwards until you get to TDC.

Once the #1 piston is at TDC, you can now adjust the valve lash for both the intake and exhaust valves on the #1 cylinder. Unscrew the adjuster screws almost all the way out of the top of each rocker arm. Now install the rocker arms (just for cylinder #1), tightening down all applicable bolts. Now tighten down the adjuster screw until it just barely comes into contact with the pushrod. It helps to determine this point by adjusting the screw with one hand, while twisting the pushrod with the other hand. At this point, you are at zero lash. Now comes the tricky part.

You want to adjust to the minimum amount of valve lash without getting valvetrain noise. For me, this turned out to be ~0.030"-0.035". On the T&D rockers, the adjuster screw has a 20-pitch thread. This means that it takes 20 full turns to turn down 1". Therefore, 1 full turn for a 20-pitch thread is 0.050". If you have a different brand of rocker arms, you will need to determine the pitch of your adjuster screws, and compensate accordingly. For my adjuster screw, starting with zero lash on the intake valve, I turned it from 12:00 to approximately 7:30. This gave me between 0.030" and 0.035" of preload. Once you get to this point, you will want to hold the adjuster screw in place, and tighten down the retaining nut. Repeat this process for the exhaust valve.

NOTE: This valve lash adjustment was used by me on Comp Cams OE-R Series lifters used in my car. The lash may vary a little with different lifters, or even the same lifters. You may want to start with a little more or a little less preload as your starting point, if you wish. FYI, I started with 0.025" of preload (exactly 1/2 turn from zero lash), and I had valvetrain noise, so I needed to readjust with an additional 0.005"-0.010" of preload.

Once you have the intake and exhaust complete for cylinder #1, it is time to move on to the next cylinder. For ease of memory, I did the front bank first (1-3-5), then the back (2-4-6). Also, the front bank is easier to work with, so you will have a little practice before you get to the back. :) So for the next 5 cylinders, repeat the steps to get the piston to TDC, then install the rocker arms, then adjust the valve lash to zero lash, then adjust to the proper amount of preload.

Once you are done, put the car together, and start it up. If you have no valvetrain noise, CONGRATS! However, if you do have some, you will need to adjust a little more preload into the rocker arms. To readjust, it is not as difficult as the initial adjustment. You will simply need to hold the adjuster screws in place, loosen the retaining nuts, adjust a small amount of additional preload (I suggest about 0.005" at a time), then tighten down the retaining nuts again, while holding the adjuster screws.
 

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Just had to say, that is a great write up Jason. I could see myself doing the adjustment the whole way.

Have you ever seen Jeff do the adjustment...while dancing, drinking a beer, and singin a song....pretty talented that guy is :D :D
 

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Discussion Starter · #10 ·
Hey, thanks, Steve. :)

I've never seen Jeff do that in person, but I have seen his Internet dance. LOL
 

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Blackice GTP said:
Have you ever seen Jeff do the adjustment...while dancing, drinking a beer, and singin a song....pretty talented that guy is :D :D
That is how mine were done :D
 

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JasonGS said:
Hey, thanks, Steve. :)

I've never seen Jeff do that in person, but I have seen his Internet dance. LOL
I was there when he did steve's car. And I can say he has some very interesting choices of words for lyrics :eek:
 
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