First off, am I correct in assuming you can run the engine with the valve covers off? Also, can you adjust the rocker arm nut with the engine running?

So just, in general, how do I know how far to tighten the nuts on my rocker arms?

Thanks for helping a newbie!

 

Yes - you can run with the valve covers off. The oil squirts out of the pushrods and makes a mess - get some cardboard or something and cut it so that it's above the exhaust manifolds, and slopes back towards the heads, so the oil runs back into the heads and stays off the manifolds (where it burns and smokes you out while you are adjusting).

I'M NO EXPERT HERE - but I've done mine and read alot about it - it may not be perfect, but what I've done was, one at a time with engine running, loosen it until it makes chatter, then start tightening it slowly until the chatter just stops, then an extra 3/4 turn I believe?

Maybe search "valve adjustment" and see what you come up with as far as how far to tighten after the chatter stops.

 

I prefer to adjust the valves when the engine is cold and off. The directions are in any haynes book and work well.

 

The re-build books SUCK for that information.

Do what newbie said, but do 1/4 turn.

 

I agree - after thinking about it more, 1/4 turn makes more sense!

 

Fit rocker arm and nut and wind down until pushrod seated in rocker. Gently rotate the pushrod with your fingers while tightening down the rocker nut.
When you first feel a slight resistance at the pushrod, you are just starting to compress the spring inside the lifter.
Turn the nut down required distance from this point.
The valve is now adjusted properly.

Do in this order; saves having to wind engine over 8 times to get each cylinder at TDC.
Mark the retainers with a marker pen as you do them so you don't mix up

Put No 1 cylinder at TDC on the balancer (check with distributor ), then do both valves on No 1 cylinder.
Without touching crank do
Drivers side ;No 3 exhaust (4th valve) No 5 intake (6th valve) & No 7 intake
Passenger side; No 2 Intake (2nd valve) , No 4 Exh (4th valve) ,No 8 Exh. (last valve)

Then rotate the engine one complete turn until the TDC mark comes back up on the mark again.
Do what's left
Drivers side ;No 3 Int No 5 Exh and No 7 Exh
Passenger side; No 2 Exh No 4 Int. Both No 6 valves and No 8 Int

While the valve covers are off , pull the coil wire out and crank over a couple of times to make sure they are all moving right.

 

I did it with engine running. I bought a valve cover at the junkyard for 4 bucks and cut the top out to stop the oil.

Like this: http://www.youtube.com/watch?v=HSR36fmBR6M

Only, I did them all exactly 1/2 turn. My shitty idle is gone, it idles real smooth now. Should I hit it again tomorrow and only do 1/4 turns or leave it?

 

I still wonder why this 1/4 turn preload recommendation doesn't just die a slow and painful death. Why so many continue to cling to the 1/4 turn OR EVEN LESS recommendations, even in spite of GM and other valvetrain leaders NOT recommending that setting.

My 96 Vette FSM even increases that to ONE FULL TURN +/- 1/4 TURN. When means that even 1 and 1/4 turn of preload is within specification. Now, there's GOT to be a reason, an engineering based reason for that recommendation by GM.

CompCams' recommendation is even more than 1/4 turn.

Crane has gone so far as to warn against it, saying valvetrain failure may result. I've got a link saved somewhere where Crane writes their extensive testing has shown lesser preload settings are dangerous. Got it from their site, so it's available for those wanting to know the straight skinny from Crane.

Sure, being 65 years old, I've read about this for many decades, the claim being that it'll add a few hundred more rpm on the top end before valve float and I've tried it. I found NO difference.

If you read posts on many other Forums, as I do, you'll virtually always see posts about valvetrain noise, rockers jumping off the valve stem and other sorts of carnage. Ever wonder why that is? Why is it that so many are experiencing such failures!?

Valvetrain noise is caused by parts hitting together - ever wonder why that is? They didn't come of the assembly line at the factory sounding that way.

To me, the bottom line is, unless I have a engineeringly proven reason to deviate from their recommendations I let the engineers guide my decisions.

Just my thoughts and attempt to put a stopper in the bottle.

Jake

 

Maybe I'm thinking of 1/4 turn after pushrod just stops freely turning between fingers when adjusting them not running. I just don't remember, at 45 with 5 teenage boys in the house, I'm going

 

You dont want the valvetrain hitting them so you will have to turn the motor and hydrolic and solid are adjusted differently


you can find the right info on youtube


engine off and most specs are for a cold engine

 

I speak about the 1/4 turn from experience. My motor barely ran at 1 full turn, same with 3/4 turn. It stumbled even worse than it does now when I had it at 1/2 turn. 1/4 smoothed it out.

 

I have done it like vetteoz posted instructions for several times with success. I am almost 100% sure I got that info from a haynes or chilton book. With hydraulic lifters there is no reason to do it when running. Also 1/4 turn is likely going to be too little pre load.

 

The KEY to the spin the pushrod method is to spin the pushrod until SLIGHT RESISTANCE is felt. Many over-look that little tid-bit of detail. There still remains a problem though since what's SLIGHT RESISTANCE to one person isn't to another.

In fact, so many mistakening adjust preload using the spin the pushrod method that many, including CompCams, NOW recommend moving the pushrod UP and DOWN until no movement can be made.


Jake

 

If that's the case, you made a basic fundamental error in the adjustment procedure. Most likely, the lifter wasn't riding on the base circle of the cam lobe when you set the preload.

Remember, of all the adjustments, the lifter being on the base circle of the cam lobe is the MOST IMPORTANT. If the lifter isn't riding on the base circle, but instead on the cam's ramps, etc., the preload adjustment will definitely be wrong.

This stuff isn't rocket science, but there is a learning curve that has to be dealt with. Once you truly get the hang of it, it becomes second nature - like learning to ride a bicycle.

Other things that tends to muddy the waters are all the different recommendations being made by guys who prefer this amount of preload or that amount of preload. Sort of like re-engineering what the engineers engineered, LOL.

Simply put, my advice is to just follow that advice of the company that makes the lifter. Should you choose to do otherwise, just be prepared to accept the consequences.

Jake

 

If its not running right on 1/2 or 1 turn, then you did not adjust them right to begin with. The 'spin the pushrod' method is dangerous at best. Quite often you can still spin the pushrod when all the slack has already been taken up and end up overtightening the nut anyway. I would suggest throwing that method out the window and tighten up the rocker until all the slack has been taken up. Check this by moving the rocker up and down and side to side until it seems like there is no more free space between the pushrod and rocker and valve and rocker. Check this very carefully, this is the most important part of your adjustment. Then tighten them up at least 1/2 turn. That will put them into the specified preload range. At 1/4 turn you are not putting enough preload on the lifter and are running loose... which could make a little more power but can also easily waste the valvetrain.

The Haynes book method is otherwise fine for 99% of us. Turning the motor for every valve or every cylinder is a complete waste of time. If you spend the time to map out the alignment of the lobes you'll find out that even with a cam with 360 degrees of advertised duration you'll still be on the base circle of half the valves at the correct crank angle.