Harland rocker re-install after head gasket?

[Heap O' Jeep]

I have a 4.6L stroker that I pulled out of a parts rig (I didn't build it, have minimal background knowledge on it) and I need to change the head gasket. I have been pulling off the Harland rockers and I can't seem to find any documentation as to the torque specs of how they go back on.

Does anyone have a link to the specs or could possibly tell me how they go back on?

Also, the studs that hold them down backed out when I was removing the nut. Any particular way to re-install those also? Thanks

 

[Johnnie Walker]

Only thing I can think is to contact the company for specs, info.

 

[Heap O' Jeep]

That's my next choice, just hoping that someone already has the info or experience on the subject

 

[2stix]

if they have studs, then they are adjustable rockers, with guide plates. (which i would think they would be being harland aftermarket.) when you go back to install them you will need to adjust them per spec. normally you tighten adjustable hydrolic lifter style rockers by turning the nut untill there is no more play. (can spin the pushrod tube with your fingers, but will start draging when zero tolerance is reached) . once you have zero tolerance, turn the nut another 1/4 - 1/2 turn. this is common for chevy V8s and such. research to make sure for the jeep. if they are the pedestal mount type, they should only have the allen bolt that holds them down and two rockers are held together with a pin. but like i said, if they have studs in the head (and hopefully guide plates installed) then you have adjustable rockers.
as for the studs. they are replacing the non adjustable rocker mounts and need to be to be tightened back into the head to spec. clean the threads, add some loc-tite and torque them down.

 

[Heap O' Jeep]

Thanks, that's the info I was looking for. There is 1 allen head bolt per rocker, none of the rockers are actually connected but they do share guide plates.

How does someone install mount studs with both ends threaded? What tool is needed?

 

[O-Gauge Steamer]

Here, from the Harland Website:

Hydraulic cams with stock rocker arms normally require 1 full turn tighter from zero lash (no clatter).
Roller rocker arms should be tightened no more than ½ turn from zero lash.

 

[Heap O' Jeep]

Apparently I'm blind, thanks for the paste. I've googled a thousand things and my life and for some reason could not find that info.

 

[Heap O' Jeep]

So from what I have read I find zero lash by rotating the engine until the exhaust pushrod on the certain cylinder I'm working on is completely to the top of it's cycle and adjusting the intake side at that time and vice-versa.

Does it matter which cycle the cylinder is on when I adjust the intake/exhaust sides?

I assume that the 1/2 turn is clockwise (tighter) and that I shouldn't be able to spin the pushrod at that point because of the tightness?

Sorry for the noobish questions, I've done quite a bit of suspension work and engine swaps but nothing relating to the valvetrain.

 

[O-Gauge Steamer]

The most secure method is to adjust the valves on a cylinder that is on it's compression stroke. Pull the plugs, and turn the engine by hand. You can use the Very High Tech Tool to find the compression stroke. It is known as your finger... Any finger will do. Just feel for the compression and that will guarantee both valves are completely closed.

BTW, everyone starts at zero experience. It is always good to ask the question. Easier than fixing a mistake.

I started asking questions, of my Dad, around 1958 or so... I am still asking questions and I hope to be asking questions for a time.

There are alternative methods that have you adjust cylinder "X" valves when cylinder "Y" has an intake open. But the upshot is that in both the text book method and my method, the target cylinder is on a compression stroke.

Try working on an engine where the manufacturer want the vales adjusted with it idling. Now there is a fun afternoon. Or, take the classic Jaguar engine whereby you adjust the vale clearance by removing the cams. Yup, remove the cams. The cam operates directly on top of the valve and the "cam follower" is a bucket with shims between the underside of the bucket and the valve stem. You start by taking the measurements of all of the existing clearances. Jot them down and then remove the cams. You then remove the bucket and the shim pack from each valve, measure it, add/subtract the required shims, reinstall the buckets, reinstall the cams and then measure. If you made a mistake anywhere, you get to do it again. Come to think of it Ferrari's adjust the same way but at least you don't have to pull the cams...

Makes our valve adjust prodeedure look like a walk in the park...

For those wondering, the accepted method for hydraulic lifters in the 60's was to have a spare valve cover on hand that had the top cut out of it. You install the cover and put clips on the rocker (actuall these can be make out of aluminium foil) at the pushrod end so the oil does not go all over everything. Then, starting at the front cylinder, you loosen the adjuster so that the valve clatters, slowly tighten it up until it just stops clattering (zero lash) and then make the prescribed adjustment. Set the lock and move to the next valve. Afterwards, new gasket and the proper cover installation. All done, of course, with the engine at operating temperature. Very old school. Not for the inexperienced either. This is not a slam on anyone, you just have to see it done prior to attempting it.

Best method? Maybe not, but it removes a ton of variables the biggest being the charge state of the lifter. I belong to the "make sure the lifter is pumped up" crowd. So, when installing a new cam/lifter I precharge the lifters in a oil prior to installing them.

 

[Heap O' Jeep]

Thanks for the help and explanation!

Another small question, is it normal that the pushrod is tight after tightening the nut the 1/2 turn but after I turn the cylinders over a rotation or 2 it's loose again? The nut becomes loose enough for me to turn it by finger also. Confused here......

 

[O-Gauge Steamer]

The adjusting nuts need to be tight. Aren't there lock nuts on the studs?

Here is the thing, a Hydraulic Lifter actually collapses to the "loaded" position as it operates. It is full of oil and has a spring to help return the cup to the "unloaded" position. It is the collapsing of the lifter that pumps the oil up the pushrod and onto the rocker. All done with metered oirifices. The lifter fills from a pressure galley in the block (that would be the orifice in the side of the lifter, usually there is a ring of material removed from the lifter in this area as the lifter rotates in operation. Without the clearance provided, the lifter would be unable to oil up) and there is an orifice on the bottom of the lifter to oil the cam lobe. The orifice in the cup is what sends the oil up the pushrod.

So.... When you adjust the lifter, you find the Zero Lash point, make the adjustment which partially collapses the lifter to the "unloaded" position. After the adjustment, the pressure on the oil in the lifter that you just put there by collapsing it will bleed off and the pushrod will then turn.

And here is another thing, if you collapse the lifter by an over adjustment, it has no way to return without oil pressure. Which is why we used to make the adjustment under idle conditions. Constant pressure supply to the lifter.

The adjusting nut(s) must be solid or the valve adjustment will walk out.

The biggest difference between a Solid Lifter Cam and a Hydraulic Lifter Cam is the point at which the lifter starts to move. A Hydraulic cam must start opening sooner as the lifter has to collapse to the loaded position before the pushrod will begin to move. Once the pushod is moving, the rest of the valve train is identical.

And, no, I am not suggesting that anyone here start adjusting the valves with the engine running. It is dangerous and can be very messy.

 

[2stix]

"and can be very messy" especially when one of the clips fly's off. ask me how i know. i have a couple sets of those clips. aluminum and spring steel. the aluminum ones tend to become loose and wiggle off. why i haven't thrown them away is beyond me, but i suppose they don't take up much room in the box.

 

[Talyn]

And here is another thing, if you collapse the lifter by an over adjustment, it has no way to return without oil pressure.

They will decompress by action of the internal spring. Let the sit a couple minutes and they will come back up.

And, no, I am not suggesting that anyone here start adjusting the valves with the engine running. It is dangerous and can be very messy.

With the adjusting nut on the pivot stud (like a Chevy) this is possible and probably the easiest way to do it. I've done it a few times and its quick and easy. With the Harland Sharp Jeep rockers the adjusters are over a pushrod and you use an allen wrench to adjust them and an open ended wrench to tighten the adjuster. Since the adjuster is over the pushrod which is moving at idle I don't see how it would possible to adjust them this way. That is assuming he has the drop in pedestal mount rockers, not the HS stud mounted rockers, which I have rarely seen used.

The way I do it is bring the cylinder being adjusted up to TDC on the compression stroke, making sure both valves are closed. If the lifters were previously compressed, loosen the adjuster and let it sit for about two minutes so the lifter can decompress. Then rotate the push rod by hand until a little of drag is felt. They turn the adjuster 1/2 to 3/4 turns more. 1/2 turn ads about .020" preload. Also, if you need to turn the adjuster more than one turn from fully backed off position you need longer pushrods. The holding pressure on the allen wrench tighten the lock nut. Also the rocker hold down bolts are torqued to stock, 21 ft-lbs

From Harland sharp:

?The most important thing is having the correct pushrod length. If you have the pedestal mount rockers, you need to screw the adjuster in the rocker as far as it will go .Then you need to back it out 1 full turn. This is where you want to start to figure your pushrod length. Set 1 cylinder at TDC and put in an adjustable pushrod, then bolt in the rockers. Start lengthening the adjustable pushrod until everything is just touching, lifter, pushrods, and rocker. This is your zero lash point. Remove the adjustable pushrod and measure it. Since the rockers are adjustable I’d add about .020 to the length to add some preload to the lifter. Now that you have your pushrods you can install the rockers. Again you want to do each cylinder at TDC, since the rockers need adjusted. Once you have the pushrods and the rockers bolted down turn each adjuster ½ to ¾ of a turn to preload the lifter and you are finished. Move on to the next cylinder and repeat the process. If you have the stud rockers let me know and I’ll email you some info. on those. Plus there are a few more steps in the installation. Thanks