Need rocker arm help please!

[us74k5]

Hey guys, im putting my engine back together, im at the rocker arms right now. I am about to set the valve lash. However I have never worked with these kinds of rocker arms before. Do i set the lash just as I would with normal ones, or do I have to do something special? Any help would be much appreciated.

 

[76zimmer]

just set the lash at the roller/valve tip by turning the nut, then lock the set screw while holding the position of the nut.

 

[us74k5]

Tell me if I am doing this right please. Number one cylinder on compression stroke, both lifters in closed position. Tighten down the big nut on the rocker arm while spinning the push rod until the slack tightens up. Then take it a half turn after that. Will that work with these rocker arms?

 

[76zimmer]

cylinder position correct. So this is a hydraulic cam then huh? Sorry I was thinking solid. So yeh, that will work with these rocker arms. When you get the engine broke in, try setting them with the engine running method.

Good luck

 

[us74k5]

The block was not rebuilt, same cam, just new valves, my lil brother over heated it and burned up two of em:-( Only 4-5k miles on the engine, so most of everything was retained, the machine shop just re did the heads.

 

[us74k5]

Ok, to be honest I do not know right now if it is a solid or hydraulic setup. I have done 3 chevy engines with stock lifters and rocker arms, no problem. But this is a new setup to me. I have no idea what cam is in it, and I really do not know how to tell. What I do know, is that when I tried to do what I had stated above, it didnt matter. The nuts went down so far, then stopped. The Push rod was still rotating, but the nut was done. The heads were assembled at the machine shop, in the exact configuration they were when removed, they just replaced a couple valves and cleaned them up. I tightened the nut on the rocker arms down on each cyliner when they were on the compression stroke. I have seen this before, and im not 100% what it is called. But I believe all you have to do is torque those nuts to a specific number. I have no Idea what the torque specs would be however. Any help would be greatly appreciated, thanks.

 

[76zimmer]

You really need to find out what cam it has, to make sure the lifters are correct for it, and to set the valve lash properly. I believe a hydraulic lifter has about 9 parts to it when disassembled, and a solid only 5. Not real sure about that though. With Hydraulic lifters, you can still turn the pushrod, even with no lash at the valvetip, as the lifter will bleed off the pressure. Loosen the rocker locknut, until you have some gap between the valvestem and roller tip, start tightening the rocker locknut, and make sure you only get to zero lash (when the stem and roller tip gap is at 0.) Then go 1/2 turn further.

 

[us74k5]

well the parts are all still the same. The cam, lifters, pushrods, rockers, etc. None of them have changed, only two valves got replaced. Before my brother over heated it, it was pushing 504 hp. And running amazing. So all of the parts are correct, and matched. I just do not know what they are because I did not build the engine, i bought it after someone else had it re built. And its not really possible for me to go 1/2 turn further, once the nut is tight, its tight. I can torque it. But I do not know what the torque specs are. With them tightened down the push rods feel almost at 0 lash. But I do not have the option to tighten them any further, which is why I am wondering if I am just supposed to sinch them down, then torque. That seems like the only option I have at this point.

 

[76zimmer]

I don't think these rocker arms require a torque setting. Just set the lash at 0 +1/2 turn. If your running out of threads, there is a problem or mis-application going on somewhere.

This might help with lifter ID:

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