Adjusting roller rockers?

[bigbadjim]

Adjusting Crane roller rockers.

The instructions say. Rotate the pushrod with your fingertips, rotate and tighten nut until you reach zero lash, turn nut 1/2 to 1 full turn more, then tighten hex lock. WHAT A CROCK!

I did this and the motor runs like $hit. Major valve float and a lot of popping!! The only way to get it to run decent and not pop is set at zero lash and tighten hex lock. NO EXTRA TURNING OF THE NUT.

Does any one know why they tell you the extra turns of the nut? Is this different with every motor? Anyone set there rockers up and have the same experience?

 

[351LX]

Most hydraulic lifters are designed to be run with a bit of preload,that is why you do the extra turns.Is there any chance your pushrods are the wrong length?I have heard of people using a small piece of paper and some grease on top of the valve to check the pattern of the rocker arm sweep to see if it is centered and using that as a means of determining the length of the pushrod.

 

[5.0 N/A]

go to www.flowtechinduction.com and go to tech info and to valve adjust and it outlines an excellent procedure for adjusting valves/rocker arms-its possible if you have used lifters that they may be sticking as i have seen this a few times or you may be missing the point at which the clearance between the pushrod and rocker arm is at zero-you usually have to watch pretty closely for this(especially on new lifters)-follow the adjustment throught the firing order and it should work out for you and then at this point you might want to check the sweep of the roller tip on the tip of the valve to make sure the push rod length is correct-what type of cam and heads are you using-valve float becomes an issue on a roller lifter engine when you start using an agressive cam like a comp cams extreme energy series,because of the added weight of the roller lifter and the aggresive lobe it can be hard to rev past 5700 rpm without valve float unless you have a really good valve spring-this is just my own experience-hope it can help you some

 

[bigbadjim]

what type of cam and heads are you using-valve float becomes an issue on a roller lifter engine when you start using an agressive cam like a comp cams extreme energy series,because of the added weight of the roller lifter and the aggresive lobe it can be hard to rev past 5700 rpm without valve float unless you have a really good valve spring-this is just my own experience-hope it can help you some

I am using a comp cam extreme energy hydraulic lifter cam, and 70' 351w heads with brand new double valve springs. I have checked my pushrod lenghth and it is fine. I readjusted my rockers again last night, by watching the distributor and setting each set of valves at a time.

Seems to run good now .... I took it for a spin and reved it up to 6500rpm a few times, seems to run fine. No lifter noise!

 

[xplict]

Jim,

I just put a set of Poly Locks on my rockers the day before I pulled the tranny. So no test run as of yet, I did follow the regular ajustment procedure of tighten till no slack in pushrod then 1/2 turn.
I did have to adjust each rocker atleast twice with manally turning the engine over, then 2 more times to make sure all play was removed then I tightened the hex screw.

As soon as I have the starter hooked back up and run it I'll let you know if I have any problems.


Big John

 

[THREE40SEVEN]

You have to be on the base circle of the camshaft in order to adjust the valve train.
To adjust per cyl:
-adjust the intake valve when the exhaust lifter/pushrod on the same cyl is just starting to come up. 3/4 turn on the adjuster nut and lock

-adjust the exhaust valve when the intake lifter/pushrod on the same cyl is 3/4 of the way down. 3/4 turn on the adjuster nut and lock

-Matt

 

[DELUXE MW]

I usually tighten only 1\4 turn