Why would you want to install 1.6 ratio roller rocker on to an engine. Because, it is easier to change the rockers than it is to install a cam. With the 1.6 roller rocker you will gain about .030's more lift and not to mention less horse power loss due to friction. Another reason is the oil temps will be lower due to less friction and also the engine will have a easier time spining up throughout the power band.
Here is a pic of the stock rocker.
Here are the roller rockers.
You can buy these through your local GM dealer, online, or in the classified section of a message board. Thats is where I got mine used with 1200 miles on them for 125 dollars. Ok so I stole them at that price. Most places new charge 270 dollars for these. Also too, these rockers only work on center bolt heads (87 and up). Thats it. They are of the "self aligning" style.
In this pic here notice at the bottom of the rocker, where the one roller is. On either side of the roller there are steel washers that go over the tip of the valve stem to keep the rocker aligned with the valve. Older style heads use a guide plate, that is under the rocker studs or use harnened push rods and the the head keeps them aligned. The stock one, which is on the right, the way it kept the rocker aligned is by bringing the stamping down over the vavle. Reason why the roller rocker needs the steel washers is the body of the rocker is aluminum. A steel vavle up againsnt aluminum doesn't work all to well. The reason why the stock one doesn't need any washers is because it is made out of steel.
Ok here is the disclaimer. By following this article, it is nothing but a suggestion on the way to upgrade your stamped rockers. IF you screw up any part of this install, you are on your own. The writer takes no responability for your mistakes. Such as, breaking a bolt, dropping a washer down into the engine, over tightening the rockers, just anything at all to cause damage to you or your car. If you screw up, you are on your own.
Ok now thats outta the way here how I installed the roller rockers into my 1989 305 TPI IROC.
Tools that are needed
A standard mechanics tool set with open ended wrenches.
Some Torx bits T-30, T-50, and a T-45.
A 3/16's allen key for the rocker nut locks.
I beleive that is it.
First off, disconnect the negative terminal off the battery. You'll be working arround the altenator and with the terminal coming off the back of it you'll hit it with the valve cover and put on a nice spark show.
After ya do that take a look over the engine and see what you have to move out of the way.
Drivers side of the engine. This is the easy side todo. The only thing that really is in the way is the alt. Thats about it. The hoses and spark plug wires you can move to the side.
Here is the passenger side. It is a little more involed todo this side cause of the air diverter valve and the heater control valve. Also what makes it a little bit harder is the wiring harness gets in the way. You can move it arround a bit to get the valve cover to clear it tho.
Now that you have done that. It is time to get dirty.
Start by moving the wires and hoses outta the way on the drivers side.
Remove the 4 torx bolts holding the valve cover on. It is a T-30 bit.
Now try to remove the valve cover. You might get lucky and be able to remove it without removing the alt. In my case that did not work. I had to remove the alt due to the terminal on the back if it. Now you can see why I said to disconnect the battery. I forgot todo it and the next thing I saw were sparks flying from the back of the alt. lol
This is how to remove the altenator in a sperpintine setup. On a v-belt car the procedure is different. Well because the alt is where the AC compressor and vice versa.
Take off the serp belt by putting a 1/2 inch ratchet into the belt tensioner.
Push it to the drivers side to release the tension on the belt and remove it from the alt.
After you do that, remove the alt by taking out the top bolt which is either a T-40 or a T-45. I cant remember right now cause my IROC had a 1/2 inch bolt in place of the stock torx bolt.
The bottm bolt on the alt is a T-50. When you get that bolt out, you can remove the alt.
When ya have the alt removed, just put it to the side. You dont have to remove any wires from it, since it only needs to be moved a few inches. Once the alt is removed, you can remove the valve cover and start taking off the the rocker arms.
Removing the rocker is straight forward. What you need is a 5/8ths inch deep socket, a 6 inch extension and a ratchet. Remove the rocker nut and pull off the rocker.
Now this part is optional. I pulled out the push rod to take a look at it just to see if it is straight, dented, blocked up, just anything in general that could be wrong with it. Well when I pulled them out they all looked like this. Oh yeah when you pull out the push rod, make note of the push rod's posistion. It devlopes a wear pattern on it that is specfic to the lifter.
Nasty looking huh? All I did to clean them up was use some steel wool and a castrol super clean on tthe outside. The inside part I sprayed some "Brake Kleen" down into the push rod to make sure it was clear and cleaned. Like I said, you don't have todo this, but I would for the peace of mind that you did it.
If you cleaned it great,lets move on, if not, you are a lazy pos that likes doing stuff half assed.
Install the push rod back down into the block. It will only go down so far and at a certian angle and height.. You can compare the angle and height of the push rod with the one next to it. That will give you a general idea if it is right or not.
Now it is time to install the rocker. There is one way todo it.If you notice down in the middle of the rocker where the shaft is, there is a flat side and and concaved side to it. The flat side goes up (atleast that is what I think). Reason why I say that is because the bottom of the lock is flat and needs something flat to go up against. Thats the way that I did. I could be wrong. So far I havent had any problems.
Top side of the rocker.
Bottom side of the rocker.
Install the rocker onto the stud making sure that it doesnt get caught up on the threads and make sure that the push rod seats into the rocker. If the push rod doesnt, it means that you do not have it sitting in the lifter right. Move the push rod arround till it sits right in the lifter and the rocker goes down as far as it can go.
Install the rocker nut and make sure that it doesnt stop on the lock. If it does, turn the lock almost all the way out with the 3/16th's allen key.
This is the tricky part. Setting the preload on the lifter. The way that I did was, I turned push rod till it stop turning as I tightened the nut. After it stop turning I put a 1/4 turn on it to set the preload.
Now to the same thing for the next seven rockers.
After you get the one side done here comes the messy part... Setting the final preload setting on the rockers.
Reinstall the alt and whatever you took off on the drivers side except the vavle cover.
I know you are thinking that I am nuts but really I'm not. The only bad thing tha happens is oil gets all over the place by doing this and it takes a little bit of time to burn off the manifolds.
Don't forget to reconnect the battery.
Go over everything make sure everything is "right" and nothing is on the way of moving parts. I know that you don't want something to get caught up in the belt or fall down into the engine.
Now start the car. If you hear any unusal noises such as clack, clack, clack, etc thats your rockers out of adjustment. Don't be alarmed, this is how you get rid of the noise.
Take your 5/8th's deep socket and go arround to each rocker and find the loudest one. Tighten that down to the clacking noise stops. Once ya do that, go to the first rocker and loosen the nut till it starts clacking again. Once it does tighten the nut till the clacking is gone and then put another 1/4 turn on it. If the engine bogs down just bilp the throttle a lil bit to bring it back to the set idle speed.
Now do that for the rest of them
After you do all of them, shut off the engine and take a break and let it cool down for a bit. Or you can do what I did and clean out the inside of the vavle cover. Reason why I did that is I didn't want to work arround some hot manifolds. lol.
Heres how I did the locks...
Tighten down the lock in the center with the 3/16th's allen key as far as it goes. Then take the 5/8th's open end and tighten the rocker nut and the allen key at the same time, about 3/16th's of a turn. That locks them so they don't back out on you. Now do the rest and thats it.
Heres what it looked like after I tightened them all down
Clean up the vavle cover gasket mating surface with a paper towel with some Brake Kleen on it till any oil residue is off of it. If there is any oil or anything left on the gasket surface there is a good chance for a oil leak. If there is some grime scrape it off with a gasket scraper or a straight edge razor blade would work also.
Remove the altenator as I said above so you can get the vavle cover back into place.
When you install the valve cover gasket it just slips into the valve cover itself. Like this......
Now reinstall everything on the drivers side and thats it for that side. When you are done it should look like this.
On to the passenger side.
The only real tricky part about the passeger side is getting the vavle cover off the head. Just because there is more in the way over here. Like the air diverter vavle and the heater control vavle. They aren't hard to move out of the way, it takes about 20 min longer todo this side because of the extra stuff over here.
First thing I did was remove the heater control vavle off the throttle body. Where the red arrow is pointing to below is the exact spot where I removed it. Why I removed it from there is that the throttle body is made out of aluminum. It doesnt break as easy as the composite heater control vavle does. Also I didn't feel like spending the 20 dollars for a new one if I did break it. When removing this, coolant will get spilled over the place. So be prepared to have a few towels arround it to soak up the coolant.
All I did with the HCV was bend it over the AC lines and shoved it into a place where it didn't get into my way.
The next thing I removed was the air diverter vavle. It is really simple to remove this. On my car there wasn't a black cover on the vavle on your car there might be one. The cover just clips into place on the diverter vavle. To remove it, just shove a screw driver under the plastic and gently pry up on the cover and it should pop off.
Once you get the cover off remove the three 10mm bolts holding on the diverter vavle. The locations of the bolts are shown in the pic below by the red arrows.
Remove the 2 middle ones first. Then down below the valve there is another 10mm bolt holding on the muffler for the blow off part of the valve. Disconnect the wiring to it and set the valve aside.
After you remove that take off the vavle cover and do the same thing for the passenger side as you did for the drivers side.
When you get ready to do the final preload adjustment on the rockers don't forget to hook the heater control vavle back up. Also you can run the car without the diverter vavle hooked up. It will not make the ECM throw a code or anything like that.
Once ya get the rockers all adjusted and the engine cooled off for a little bit, reinstall te vavle cover. You might have to remove the heater control vavle again just to get it out of the way. I did.
When you are installing the vavle cover, becareful that the vavle cover gasket doesnt fall out of the groove for it. It did on me a few times before I got it back into place.
Put the vavle cover bolts back in and tigthen them down.
Reinstall the air diverter vavle and the assoicated hoses that go with it.
Reattach the heater contorl vavle to the throttle body
Whoo hoo! Now that ya did all that you are done. NOT!!!!!!1 You still have to check the car for leaks!!!! Before ya start the car back up again to check for leaks. Make sure coolant is topped off from the some that you might have lossed when you removed the heater control valve.
Start the car up and check for leaks.
If there isn't any leaks it should look like this.
Yep that is smoke coming off of the manifolds from where the oil splashed onto them.
After the oil is burned off the manifolds take it arround the block a few times and have fun!
That is how you install GM 1.6 Roller Rockers. Any questions or comments should be sent to firstname.lastname@example.org.