Installing RR on my LT1. My question is valve adjustment, in my chiltons manual, it goes throught the valave adjustment steps, but for roller rocker LT4 it just says torque to 18 lb. So is that all I have to do, or do I still need to do the TDC and rotate the engine thing?

 

I found the easiest way was to run the motor with the valve covers off and tighten down each rocker till it stopped tapping, then I gave it about another 1/8 turn.

I tried the other various methods but when I started it up they clattered. Motor running was the only way I successfully got them right.

 

I agree, motor running is the only way.

 

Wow really? sounds messy.

 

It's not bad. A few pieces of cardboard tucked into the edge of the heads catch the bit of oil spray. If you rev it up it'd make a mess but at idle it's relatively clean procedure.

 

I'm going to do my roller rockers on my L-83 this afternoon. Gonna try the "book" procedure and see how it goes. I've never been a fan of running the engine with the covers off and as much work as it would take on mine (A/C compressor and a'ssy belt, etc.) I'd rather just do it factory style and see how it goes.

 

If you do this, I'd like to see some pictures of the car running with the valve covers off and how you went about using the cardboard to catch the oil. Also the procedure and pics for tightening down the rockers. I would get roller rockers too and do the job toalso if I had some pictures for reference. Just being told how to do something is only half, you need to se it being done too. At least that's how I am with some things.
I have read that this is a good mod to do on an older engine as the stamped steel ones are not as strong and could have bent. Can somone explain this?

 

Adjusting lifter preload with the engine running is an old, out-dated method of performing that task. It's been around from decades but has fallen out of favor because a new and better method is now the most frequently recommended procedure. Some guys still cling to the old method and it'll work, but only if done correctly (same with all of the differing methods - they have to be done correctly).

Same with the method shown in many manuals - the one where you're required to go from one side of the engine to the other side then back again. That method is too confusing and regularly causes confusion and mistakes.

The procedure which is most often recommended now is the Intake Closing/Exhaust Opening method which you'll find on CompCams' website (and others).

As far as your question, LT1 engines and LT4 engines use COMPLETELY different procedures for setting lifter preload.

LT4s have what GM calls "net build" valve trains where the rocker nut is simply tightened to a specific torque and that's all there is to it. That doesn't work on LT1 engines.

LT1s, however, are completely different and call for the adjusting nut to be turned one full turn (+/- 1/4 turn) from zero lash. That required procedure is much more involved.

I wrote a step by step procedure to set lifter preload and have it posted as a STICKY on this and other Forums - LS1LT1.COM, etc. I wrote it with those who are unfamiliar with setting lifter preload in mind.

Track it down and it'll walk you through how to do it.

DON'T TRY USING THE LT4 PROCEDURE ON A LT1 ENGINE - IT WON'T WORK AND WILL CAUSE DAMAGE TO YOUR ENGINE!

Jake

 

I've actually done that on another vette after I put new headgaskets on it, so I know how to do it, I just wanted to know if I had to or not. Thanks good to know.

 

Why cant I thread my nut onto the studs when installing my roller rockers

 

And for anyone wanting to set the LT1s with the motor running it is messy, too messy for me. For next to nothing you can get little stoppers that you can put on the pushrod end of the rocker that will keep the oil loss to a minimum.