sahlomonic

iTrader: (1)

I've done a 5 page search on this site about installing 1.6 rocker arms and can't find the info I need.

What I'm looking for is the full installation procedure to to a 1.6 rocker arm upgrade to a stock LB9 engine.

Is it as simple as it seems? Replace and torque down to xx ft/lbs?

(excuse my ignorance, first time doing this)

Vader

SBC (Gen 1) rockers are NOT torqued to a specification. They are adjusted to a zero-lash point then adjusted another 0.020-0.030" to set the lifter plunger at the midpoint of its travel in the lifter body. Rocker arm nut torque specifications are for 60° V-6 Chevy engines and other designs.

Vader

As for the rocker arm installation, what type arms are being installed? That may affect how they are checked for clearance, whether lash caps or spring shims need to be used, and whether the rocker studs need to be replaced.

sahlomonic

iTrader: (1)

They are ProForms I bought from a forum member.

Vader

ProForm aluminum? With top-lock nut/screws?

sahlomonic

iTrader: (1)

http://www.summitracing.com/parts/pro-66915

Vader

Don't take this as judgemental, but if you are intending to use this as a daily driver you may want to reconsider using aluminum, or at the least do not throw away your old stamped steel rockers.

Trial fit one rocker on an intake valve and an exhaust valve. Verify that there is adequate clearance between the two trunnions, between the long end of the rocker and the spring retainer at the fully closed and open positions, and verify that the roller tip remains on the valve stem through the entire range of movement. Then verify adequate clearance between the rocker and the stud boss. Check the clearance between the push rod and head through the entire range of travel.

sahlomonic

iTrader: (1)

Not judgmental at all. My Z28 isn't a daily driver, and this isn't meant to stay for the long run. The price was good enough for some cheap HP that'll get me what I want out of it for a couple years until I have a new build to put in.

I had read on various posts here that 1.6 rockers would be a 'direct bolt-in' and easy installation but was unsure how to verify this.

Thanks for the info!

Vader

Even with the top-locks you may want to drip a little LocTite 242 (removable) onto the cap nuts before that final adjustment. Been there.

redneckjoe

i've been running these same rockers on my camaro for 10 years with no problems.
also installed a set on my 2.2 s-10 daily driver. no problems.

no directions with them? i thought they came in the package?

sahlomonic

iTrader: (1)

They do have instructions, but being my first time doing something like this, some of the procedures are 'greek' to me and wanted to make sure I have all my bases covered.

AlkyIROC

Installing the 1.6 rockers is no different than installing any other rocker. Basic mechanic knowledge. No special instructions required.

As mentioned above, each rocker is adjusted when the lifter is on the base circle of the cam. The rocker is adjusted to zero lash then is given the proper amount of preload for the lifter. This is generally 1/2 turn from zero lash. Once adjusted, the lifter will bleed down and the rocker will feel loose again. DO NOT tighten the adjustment nut more. The rocker is already adjusted.

All the rockers can be adjusted with one revolution of the crankshaft. Bar the engine over by hand until the timing mark lines up. You're either on #1 or #6 TDC. You'll have to look at the rockers to determine which one. Once you figure out which it is, half the rockers can be adjusted since half of them are on the base circle. Bar the engine over until the timing mark lines back up and adjust the other half of the rockers.

Problems you may encounter with aluminum 1.6 rockers.

The body is much bigger than the stamped steel rockers. A stock valve cover may not fit. Each application is different so you need to check.
Those rockers are listed as self aligning. Are your heads designed for self aligning rockers?
To go from a 1.5 ratio to a 1.6 ratio, something needs to change. Since the distance from the stud to the valve can't change, the length of the rocker on the pushrod side is increased to get the extra ratio. This will move the pushrod higher in the guide hole. Depending on the head, this guide hole might need to be slotted higher.

paulo57509

Regarding elongating the pushrod guide hole in the head, I bought this years ago; I can't recall where or why but it's in my tool box. I don't know how well these things work because I've never used it. I think they're still available.



It's used with a drill bit.

Vader

All of this is entertaining, but doesn't help the original poster resolve his questions. In other words, let's just tone it down a couple notches and try to help out with straight answers. Thanks for cooperating.

As for what people decide to do with their sacks of nuts, most of us are not that concerned over any of that as long as you don't waste them. Nuts don't just grow on trees, you know. Oh - Wait....

Vader

sahlomonic - AlkyIROC has good information.

PRESUMING the engine in question is in the 1992 in your signature, there is a very good chance that it used self-aligning rockers, and as such there will be rather large push rod holes in the heads which will not require any clearancing. It is incumbent upon you to verify that. Once you've cleared that hurdle, you should follow the rest of the advice about checking clearances and valve tip position.

FWIW, I've been running steel 1.6:1 roller tip rockers on my '86 TA (non-self aligning rockers back then) and it made almost no noticeable difference in performance. Fortunately, the cam is so tame that it also caused no problems with spring interference, seal crush, or anything else. All it accomplished was to get the somewhat "lame" cam profile into a range that is just a little less lame.

Keep us posted.

big hammer

I ran 1.7's on a stock L98 cam and springs with no issues.

Abubaca

iTrader: (3)

So lots of info on whether or not they'll fit, elongated pushrod holes, and setting lash, yada yada. All good, and important info. ....having recently installed my first set of full roller rockers, I learned a lot of info on how to properly tighten down the rocker nut and lock.

I won't go into setting the zero lash, and how far you should turn PAST zero lash, but for the sake of discussion, my rockers called for a half turn. Sooooo....apparently, lots of people have problems with the rockers coming loose, using the logical process of setting zero lash, going a half turn, and then hand tightening the lock. That's how I would've done it too. ....and keep in mind I found no formal instructions on this, just lots and lots of forum discussions. What works best is set zero lash with the rocker nut, THEN hand tighten the lock before turning past zero lash. With the nut a zero, and the lock hand tight, turn both the nut and the lock together, at one time, to a 1/2 turn past zero. This effectively gives you a half turn more on the lock. Some guys (per my reading) will then back off the nut a quarter turn while holding the lock, then tightening both back down a quarter. This gives the same 1/2 turn past zero, but 3/4 turn tighter on the lock. Hope that helps!

John in RI

iTrader: (167)

I wrote this long-long ago,.... Hope that it helps !



http://berlinetta.info/Lash.htm

(P.S. If your still using the original CAM and lifters than the shop manual calls for 1 full turn after ZERO lash. I ALWAYS set new rockers on original CAM/lifters to 7/8 of a turn - slow, even and steady turns,.... NO backing up ! )

big hammer

I'm opposite. I always go around 1/3 of a turn past zero.