Adjustable rockers/Hydraulic Lifters

[65 Dartman]

As the title states I have a question about adjustable rockers and hydraulic lifters in a 70 340 motor I'm slowly assembling. When I got the motor it had adjustable rocker arms and hydraulic lifters. Since that's what I have, that's what I'll be using along with a new Racer Brown cam and new hydraulic lifters. The machine shop guy said I should use adjustable rockers due to some previous milling on the head. What ballpark setting would be recommended prior to start-up and then after the cam is broke in? If I were using solid lifters I wouldn't have a problem setting them but I'm kind of hazy on the adjustable/hydraulic set-up.

 

[70aarcuda]

adjust them in the same order as a solid..but instead of setting a lash...you are setting preload.

you want to get to zero lash...then add preload of about 3/4 of turn on the adjuster...

and DO NOT soak the lifter in oil prior to starting the engine...you dont want the lifters pumped up with oil...

makes starting the engine harder and might hang a valve open

 

[dusterdon]

With the rocker in question on its base circle, loosen the adjuster so the pushrod will easily spin between your thumb and index finger. tighten the adjuster until it just snugs up. Tighten another 1/4 - 1/2 turn. that's it. repeat for the other 15.

 

[340sFastback]

Here is some info:

http://www.moparts.org/Tech/Archive/motor/14.html

I would ask Racer Brown how much pre load you should be running with those lifters. Not all lifters are the same.

I would also recommend adjusting with the intake off so you can watch the plunger on the lifter to determine zero lash. With no oil in the lifter its not easy to tell with the intake on because the plunger spring is very light and compresses easily.

 

[waggin]

with the intake off,you can use a wire feeler gauge between the plunger for the lifter and the retaining ring.or 1/4 turn =.020 which preload should be between .020 and .040 but best to check with racer brown.run one to 0 lash and back the adjuster off until an .020 flat feeler gauge will fit to double check,also look over the botom side of the rockers to make sure they are not rubbing on your valve springs and also look to see that the pushrods are not to long,if the adjuster has to be backed way out to achieve proper preload the cup of the pushrod will hit the rocker arm(this is just my opinion dont ask me why it is opinion but just to save my hide from experts)sorry for the rant but just check to make sure. rocker arm geometry problems are no fun and make sure you put the intermiediate shaft in properly(refer to a service manual)and get the good oil for the break in(I use rotella)some extra chemical in it....................zinc,that's it zinc.good luck on it keep it revvin 2000 or so for atleast 20 minutes but read all the instructions/destructions with the kit good luck!