In this chapter I am going to go through installing the valvetrain... In the last chapter I showed you how to the heads on the block... Now it's time to install the lifters, pushrods, and rocker arms...
This is the next step to continue after Sections 1 - 12... If you missed one of them, you can find it here...
How to Rebuild a Small Block Part 1: Block Prep
How to Rebuild a Small Block Part 2: Cam Bearing Install
How to Rebuild a Small Block Part 3: Install Water Jacket and Oil Galley Plugs
How to Rebuild a Small Block Part 4: Pre Flight Inspection After Machine Shop Before Assembly
How to Rebuild a Small Block Part 5: Crankshaft Install
How to Rebuild a Small Block Part 6: Installing Rings on Pistons
How to Rebuild a Small Block Part 7: Install Pistons in Block
How to Rebuild a Small Block Part 7a (Optional): CC the Engine Cylinder to Find Compression
How to Rebuild a Small Block Part 8: Install the Camshaft
How to Rebuild a Small Block Part 9: Install Camshaft Thrust Plate
How to Rebuild a Small Block Part 9A (Optional): Timing Chain Options
How to Rebuild a Small Block Part 10: Install Timing Chain
How to Rebuild a Small Block Part 11: Check Piston-to-Valve Clearance
How to Rebuild a Small Block Part 12: Installing the Heads
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Hello everyone, it's Krazykuda here to show you how to rebuild a small block... This article is to help any newbies through rebuilding a small block Mopar LA engine, but may have a few tips that some of you seasoned builders may find useful... If you haven't ever built an engine, I will show you what you need to know to do it yourself...
The goal of this series is to show what you can do at home in your own garage... Go at your own pace and ability and then take it to someone knowledgeable for what you are not capable of doing yourself or don't have the proper equipment/tools for...
Keep checking back in from time to time as this is a work in progress and I plan to keep updating it as I build more engines and can show you more variations...
I am going to break this into sections that you can follow along with and make sense to do in 'stages' when you build... Plus you can then jump to the section that you are working on to help keep from sorting through one very long thread to find what part that you are working on when you are doing it....
*************************************************************************
*** Important Note *** Sometimes things may not go right and you will run into a snag/road block... Do not get in a hurry to finish and take short cuts that may compromise your build...
Step back, take a break, and think about it for a while... Or seek help from other experienced people or professionals to overcome the problem... Do it right and don't take any unnecessary chances that may compromise the integrity of your build...
If you don't fix the problem correctly, it may come back to haunt you and cost even more time and money than if you took the time to think about it and research it to fix the problem correctly...
This has been a public service announcement from krazykuda....
*************************************************************************
In the last chapter, we installed the heads, now we are going to install the valvetrain... This includes the lifters, pushrods, and rocker arms...
I like Rhoades lifters... I have been using them for over 40 years and never had a problem with them... The thing I like about them is they are variable duration lifters... They bleed down under 3500 RPM taking out some lift and duration from the camshaft making it more streetable with; smoother idle, more low end torque, increased idle vacuum, better off idle performance, and better MPG... It's like having an adjustable cam, you get better low end performance without sacrificing top end power... You can pick a slightly larger cam than you need and then throw in Rhoades lifters... They take out about 15° duration and .020" of lift at idle and then ramp up to full lift and duration by 3500 RPM... You can also run them with low ratio axle gears and stock torque converters...
Here's a link to their website...
Rhoads Lifters
When using hydraulic lifters, it's good to prefill them with oil to pump them up... Put them in a clean jar, then fill the jar with oil about an inch above the top of the lifters...
If you don't have a jar, I take an old plastic quart oil container and cut it about 2" - 3" taller than the lifter...
Then put some lifters in the container... Don't fill with oil before installing the lifters because as you add more lifters the oil level rises... It's better to add the oil after you place the lifters in the container...
Here are the lifters in the oil...
Take a pushrod and slowly press down on the plunger in the center of the lifter... You will feel the plunger move a little and an air bubble will come out... Keep pressing the plunger up and down until it gets stiffer and the plunger will not go down any more.... Now the lifter is filled with oil... Then move on to the rest of the lifters until all of the ones in the container are pumped up... Then put the finished lifters in the block and do another batch until all of the lifters are done...
Take some Motor Honey or STP and coat each lifter bore using your finger to spread it all around the top and bottom of each hole...
Next you will coat the camshaft with break-in lube... Start with the front side of the block... Squeeze the lube onto the camshaft and let it drip to coat the cam lobes...
It should look like this... Here is the front side...
Then move onto the back end of the block...
Now install the lifters into the bores, it may take a little finesse to get them started... You have to get them properly straight and aligned to get them in the lifter bores...
Move onto the rest of the lifters in the container and install them into the block...
If you are installing solid lifters, they install the same way, you just don't have to pump them up with oil like the hydraulic lifters... Just dunk each lifter into a jar of oil before installing them into the lifter bores...
Now we are ready to install the pushrods... There are two styles of hydraulic lifter pushrods, solid and hollow... The hydraulic lifter pushrods have ball tips on each end... They are shown in the picture below... Adjustable rocker pushrods have a ball on one end and a cup on the other... I will show a picture of them later...
The top one is the hollow tube pushrod and is what many aftermarket suppliers make... The solid rod is the one on the bottom and is what the factory typically used... Don't pay attention to the length of the ones in this picture as they are for different applications, the photo is just to show the two different types... I do not recommend mixing solid and hollow tube pushrods in the same engine, go with one style or the other...
I weighed them once and there was not much difference in weight... The hollow tube pushrods are a little fatter, and I would recommend checking them for clearance in the pushrod holes of the head after you install the rocker arms in the engine to make sure they don't rub on the side of the holes when the valve opens and closes.... Especially if you are using a higher lift cam... Rotate the crank and make sure the pushrods don't contact the pushrod holes in the head as the valve opens and closes after you install the rocker arms..
Here's what it looks like with all of the pushrods installed on both sides...
A closer view... Make sure the ball end of the pushrods are all properly in the center of the plunger of the lifter...
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Now the pushrods are in, it's time to set up the rocker arms and shafts...
There are left and right rocker arms... The ball sockets for the pushrod ends are offset so you have to make sure they are on the correct side...
Here I'm pointing to the different side offsets...
Here's a newer set that you can see the offset and the "LT" and "RT" stamped into the arms... The LT arm has a left offset and the right arm has a right side offset for the ball end where the pushrod seats... The left side rocker arm goes on the left side and the right side rocker arm goes on the right side as you look at the shaft from the top as installed on the engine for each set of valves...
I like to separate the valves into sets before putting them on the shafts... The top of the shaft does not have oil holes as you can see in the picture below...
Here are the bottom of the shafts and you can see the oil holes in the shiny part where the bottom of the rocker arm contacts the shaft... The oil holes go to the bottom when installed on the head...
Here I circled the oil holes with green...
Here the offset ball sockets are shown by the arrows...
If you haven't chased the threads in the heads for the rocker arm bolts, now is the time to do it... They are 5/16" x 18 coarse thread bolts... Use a 5/16" coarse thread tap to chase the threads in the head bosses for the rocker arms, and then chase the bolt threads with a 5/16" x18 die... Make sure to clean the flutes of the tap and die after each bolt so you get a good clean thread to work with...
I like my Irwin/Hanson tap and die kit...
There are two types of spacers, narrow and wide, that go on the rocker arm shaft bolts... Here is the narrow one...
Here is a closer picture of the narrow spacer and a rocker arm bolt... This bolt has 3 lines on it which signifies that it is a grade 5 bolt...
Here is the wide spacer on a fully assembled rocker shaft... Notice that the rocker arms have the right and left offset for the pushrod offset outboard for each pair of rocker arms for each cylinder...
Here's a close up of the wide spacer and other brand of factory rocker arm shaft bolt... You may recognize this "H" marking that signifies it was made by Cold heading... The factory used more than one supplier for the bolts and it's ok to mix them on the same shaft... You can see the three marks on the circle of the bolt to signify that it is also a grade 5 bolt as the other one shown above...
When you set up the shaft, the narrow spacers go on the #1, #3, and #5 bolt positions... The wide spacers go on the #2 and #4 bolt positions on the shaft like this... Always verify that you have the ball sockets of the rocker arms for the pushrods offset to the outboard for each cylinder and the spacers for the bolts alternate starting out with narrow, wide, narrow, wide, narrow for the shaft...
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Installing the rocker arms and shafts...
When you get all of the rocker arms on the shaft, make sure the bolt heads are on the top of the shaft and the oil feed holes in the shaft are downward, it's time to install the assembly on the head... The rocker arms will tend to hang upside down...
Hold the shaft so the valve tip side of the rocker arms are toward the engine and the ball socket side is facing you... Bring the shafts to the side of the valves, contact the valves, then roll the shafts and let the valves turn the rocker arms to the proper position like this...
Valve tips down and let the valves twist the rocker arms as you bring the shaft to the head... Use the valves and springs to catch the rocker arm and rotate it as you install the shaft on the head like shown in the next few pictures... This way you aren't fighting all of the rocker arms separately at one time while trying to install them... It's easier...
Roll the shafts into position...
And down... Houston we have landed...
Make sure that all of the pushrod ends seat properly in the ball socket part of the rocker arm before you tighten them...
There is no adjustment needed for the stamped steel rocker arms... Just torque the shafts and you are done... That is the beauty of the Chrysler stamped steel hydraulic rocker arms...
*************** WARNING *************** WARNING *************** WARNING *************** WARNING ***************
There is an error in some years of the factory service manuals for the rocker arm torque... The incorrect torque is called out at 30 foot pounds and they say the threads are 3/8" x 16... IF YOU TORQUE THEM TO THAT SPEC, YOU WILL STRETCH THE BOLTS AND MAY BREAK THEM...
THE CORRECT TORQUE FOR THE ROCKER ARM BOLT SHAFTS IS 180 - 200 INCH POUNDS...!!!
The 69 Dodge, 69 Plymouth, and the 70 Dodge service manuals state they are 3/8" x 18 bolts and torque to 30 foot pounds... This is not correct and will ruin the bolts if you torque them that much...
This was corrected in the 70 Plymouth and 71 Dodge and Plymouth service manuals and you will see that they are correctly identified as 5/16" x 18 threads in those manuals and torque to 200 inch pounds...
The early 60's service manuals called out 15 foot pounds, which converts to 180 inch pounds and is acceptable, but I would use an inch pound torque wrench instead of a foot pound torque wrench for a torque that low to be accurate...
*************** WARNING *************** WARNING *************** WARNING *************** WARNING ***************
The correct torque for the rocker arm shaft bolts is 200 inch pounds as called out in the 70 Plymouth service manual as shown below... Use an inch pound 3/8" drive torque wrench to torque these as it is too low for a 1/2" drive foot pound torque wrench to be accurate... Remember slow and steady pull always when using a torque wrench to tighten a bolt or nut for accurate torque...
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Adjustable rocker arms...
Now we will show the adjustable rocker arms... They install mostly the same procedure as the hydraulic rocker arms, but there are a few differences...
Here is a shaft assembly with the adjustable rocker arms... You can see that the rocker shaft bolts have the same narrow and wide spacers under the bolts and the narrow spacers are in the #1, #3, & #5 bolt holes and the wide spacers are in the #2 and #4 bolt holes just like the hydraulic rocker arms... However there is a round spacer that goes between each pair of intake and exhaust rocker arms...
All of the adjustable rocker arms are the same, straight with no offset and can go in any position...
Here they are shown mocked up on a loose head... The angle of the picture makes the outboard rocker arms look offset, but they are actually straight...
From the other side...
Here are the pushrods for the adjustable rocker arms installed in an engine ready for the rocker arms to be installed... You can see the cup ends on the top of the pushrod for the ball of the adjusting stud for the rocker arm to contact...
Here is a close up of the rocker arm with the stud in the cup end on the right side and the left side without the pushrod showing the end of the ball stud that goes into the cup end of the pushrod... The cup is in contact with the bottom of the rocker arm because the stud is not adjusted yet in this picture... When adjusted properly there should be at least 1 1/2 threads or more showing below the rocker arm...
Here I have circled the cup end of the pushrod with the rocker arm stud, and pointing to the ball end of the stud on the other side... Note that these are not adjusted, just put together for illustration purposes.
When installing the adjustable rocker arm shafts to the head, use the same procedure as explained above for the hydraulic non-adjustable (stamped steel) rocker arms... Back off the adjusting studs before installing the rocker arms like the one in the picture above so they do not bind... Torque the rocker arm shaft bolts to the same torque as the stamped steel rocker arms...
Put the valve tips down and roll them over the springs until you seat the shaft on the rocker shaft bosses in the head, just like the procedure for the stamped steel rocker arms as described above... Make sure that all of the rocker arm ball stud ends are properly seated in the cup end of the pushrod before torqueing... Tighten to 200 inch pounds with a 3/8" drive torque wrench with a slow and steady pull...
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Now to adjust the rocker arms...
On a solid lifter cam, look up the proper specs for the proper year and engine that you are adjusting for a stock engine, or contact the manufacturer of the cam that you have installed if you are running aftermarket solid cam and/or aftermarket rocker arms... Many times the intake and exhaust valves are different clearances, the exhaust valves usually have more clearance...
When you adjust a valve, the cam must be on the base circle of the lobe so the lifter is not on the nose of the lobe to adjust it... That way the valve is closed and there isn't pressure on the valve... Since we have the intake manifold off, it's easy to see the cam and the lobe for the valve that we are working on... Rotate the crank so the both valves are closed for the cylinder that you are working on... Watch for the intake valve to close as that is where both valves for that cylinder will be on the base circle...
Take a feeler gauge with the proper thickness and place it between the rocker arm and valve stem... Tighten the adjusting stud on the rocker arm while rotating the pushrod... When the pushrod won't rotate with the feeler gauge between the valve stem and rocker arm, back it off a smidgeon until you can rotate the pushrod with some resistance... Then repeat with the proper clearance for the other valve... Repeat for each cylinder making sure that you rotate the crank until both valves are closed (just after the intake valve closes) and you are not on base circle for that lobe...
For a hydraulic cam with adjustable lifters, contact the cam and/or lifter manufacturer for the proper adjustment procedure...
If you adjust the valves too loose, you won't get full lift and duration for your cam and you won't get the maximum power and efficiency out of your engine... If they are adjusted too tight, the valve may not close all the way and will cause low cylinder pressure and a valve may hit a piston and damage a piston or the whole engine in extreme cases... So it is important to have your valves adjusted properly...
Here are the clearance specs for a factory 67 273 with solid lifters and adjustable rocker arms...
When the valves are properly adjusted, there should be 1 1/2 to 3 threads showing below the rocker arm... Also rotate the crank a few turns and watch the valve open and close for each cylinder to make sure the spring doesn't contact the rocker arm during movement, I've seen this happen and had to grind some clearance to keep the valve spring from rubbing the bottom of the rocker arm while opening and closing the valve...
This is what it should look like when everything is done...
Now you are this far, cover the engine until you work on it to keep it clean and free of any loose parts that may be falling... Set the intake manifold and valve covers on the engine and put a rag in the distributor hole to keep things out...
Next we will move onto preparing the timing chain cover...
How to Rebuild a Small Block Part 14: Preparing the Timing Chain Cover
This is the next step to continue after Sections 1 - 12... If you missed one of them, you can find it here...
How to Rebuild a Small Block Part 1: Block Prep
How to Rebuild a Small Block Part 2: Cam Bearing Install
How to Rebuild a Small Block Part 3: Install Water Jacket and Oil Galley Plugs
How to Rebuild a Small Block Part 4: Pre Flight Inspection After Machine Shop Before Assembly
How to Rebuild a Small Block Part 5: Crankshaft Install
How to Rebuild a Small Block Part 6: Installing Rings on Pistons
How to Rebuild a Small Block Part 7: Install Pistons in Block
How to Rebuild a Small Block Part 7a (Optional): CC the Engine Cylinder to Find Compression
How to Rebuild a Small Block Part 8: Install the Camshaft
How to Rebuild a Small Block Part 9: Install Camshaft Thrust Plate
How to Rebuild a Small Block Part 9A (Optional): Timing Chain Options
How to Rebuild a Small Block Part 10: Install Timing Chain
How to Rebuild a Small Block Part 11: Check Piston-to-Valve Clearance
How to Rebuild a Small Block Part 12: Installing the Heads
*************************************************************************
Hello everyone, it's Krazykuda here to show you how to rebuild a small block... This article is to help any newbies through rebuilding a small block Mopar LA engine, but may have a few tips that some of you seasoned builders may find useful... If you haven't ever built an engine, I will show you what you need to know to do it yourself...
The goal of this series is to show what you can do at home in your own garage... Go at your own pace and ability and then take it to someone knowledgeable for what you are not capable of doing yourself or don't have the proper equipment/tools for...
Keep checking back in from time to time as this is a work in progress and I plan to keep updating it as I build more engines and can show you more variations...
I am going to break this into sections that you can follow along with and make sense to do in 'stages' when you build... Plus you can then jump to the section that you are working on to help keep from sorting through one very long thread to find what part that you are working on when you are doing it....
*************************************************************************
*** Important Note *** Sometimes things may not go right and you will run into a snag/road block... Do not get in a hurry to finish and take short cuts that may compromise your build...
Step back, take a break, and think about it for a while... Or seek help from other experienced people or professionals to overcome the problem... Do it right and don't take any unnecessary chances that may compromise the integrity of your build...
If you don't fix the problem correctly, it may come back to haunt you and cost even more time and money than if you took the time to think about it and research it to fix the problem correctly...
This has been a public service announcement from krazykuda....
*************************************************************************
In the last chapter, we installed the heads, now we are going to install the valvetrain... This includes the lifters, pushrods, and rocker arms...
I like Rhoades lifters... I have been using them for over 40 years and never had a problem with them... The thing I like about them is they are variable duration lifters... They bleed down under 3500 RPM taking out some lift and duration from the camshaft making it more streetable with; smoother idle, more low end torque, increased idle vacuum, better off idle performance, and better MPG... It's like having an adjustable cam, you get better low end performance without sacrificing top end power... You can pick a slightly larger cam than you need and then throw in Rhoades lifters... They take out about 15° duration and .020" of lift at idle and then ramp up to full lift and duration by 3500 RPM... You can also run them with low ratio axle gears and stock torque converters...
Here's a link to their website...
Rhoads Lifters
When using hydraulic lifters, it's good to prefill them with oil to pump them up... Put them in a clean jar, then fill the jar with oil about an inch above the top of the lifters...
If you don't have a jar, I take an old plastic quart oil container and cut it about 2" - 3" taller than the lifter...
Then put some lifters in the container... Don't fill with oil before installing the lifters because as you add more lifters the oil level rises... It's better to add the oil after you place the lifters in the container...
Here are the lifters in the oil...
Take a pushrod and slowly press down on the plunger in the center of the lifter... You will feel the plunger move a little and an air bubble will come out... Keep pressing the plunger up and down until it gets stiffer and the plunger will not go down any more.... Now the lifter is filled with oil... Then move on to the rest of the lifters until all of the ones in the container are pumped up... Then put the finished lifters in the block and do another batch until all of the lifters are done...
Take some Motor Honey or STP and coat each lifter bore using your finger to spread it all around the top and bottom of each hole...
Next you will coat the camshaft with break-in lube... Start with the front side of the block... Squeeze the lube onto the camshaft and let it drip to coat the cam lobes...
It should look like this... Here is the front side...
Then move onto the back end of the block...
Now install the lifters into the bores, it may take a little finesse to get them started... You have to get them properly straight and aligned to get them in the lifter bores...
Move onto the rest of the lifters in the container and install them into the block...
If you are installing solid lifters, they install the same way, you just don't have to pump them up with oil like the hydraulic lifters... Just dunk each lifter into a jar of oil before installing them into the lifter bores...
Now we are ready to install the pushrods... There are two styles of hydraulic lifter pushrods, solid and hollow... The hydraulic lifter pushrods have ball tips on each end... They are shown in the picture below... Adjustable rocker pushrods have a ball on one end and a cup on the other... I will show a picture of them later...
The top one is the hollow tube pushrod and is what many aftermarket suppliers make... The solid rod is the one on the bottom and is what the factory typically used... Don't pay attention to the length of the ones in this picture as they are for different applications, the photo is just to show the two different types... I do not recommend mixing solid and hollow tube pushrods in the same engine, go with one style or the other...
I weighed them once and there was not much difference in weight... The hollow tube pushrods are a little fatter, and I would recommend checking them for clearance in the pushrod holes of the head after you install the rocker arms in the engine to make sure they don't rub on the side of the holes when the valve opens and closes.... Especially if you are using a higher lift cam... Rotate the crank and make sure the pushrods don't contact the pushrod holes in the head as the valve opens and closes after you install the rocker arms..
Here's what it looks like with all of the pushrods installed on both sides...
A closer view... Make sure the ball end of the pushrods are all properly in the center of the plunger of the lifter...
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Now the pushrods are in, it's time to set up the rocker arms and shafts...
There are left and right rocker arms... The ball sockets for the pushrod ends are offset so you have to make sure they are on the correct side...
Here I'm pointing to the different side offsets...
Here's a newer set that you can see the offset and the "LT" and "RT" stamped into the arms... The LT arm has a left offset and the right arm has a right side offset for the ball end where the pushrod seats... The left side rocker arm goes on the left side and the right side rocker arm goes on the right side as you look at the shaft from the top as installed on the engine for each set of valves...
I like to separate the valves into sets before putting them on the shafts... The top of the shaft does not have oil holes as you can see in the picture below...
Here are the bottom of the shafts and you can see the oil holes in the shiny part where the bottom of the rocker arm contacts the shaft... The oil holes go to the bottom when installed on the head...
Here I circled the oil holes with green...
Here the offset ball sockets are shown by the arrows...
If you haven't chased the threads in the heads for the rocker arm bolts, now is the time to do it... They are 5/16" x 18 coarse thread bolts... Use a 5/16" coarse thread tap to chase the threads in the head bosses for the rocker arms, and then chase the bolt threads with a 5/16" x18 die... Make sure to clean the flutes of the tap and die after each bolt so you get a good clean thread to work with...
I like my Irwin/Hanson tap and die kit...
There are two types of spacers, narrow and wide, that go on the rocker arm shaft bolts... Here is the narrow one...
Here is a closer picture of the narrow spacer and a rocker arm bolt... This bolt has 3 lines on it which signifies that it is a grade 5 bolt...
Here is the wide spacer on a fully assembled rocker shaft... Notice that the rocker arms have the right and left offset for the pushrod offset outboard for each pair of rocker arms for each cylinder...
Here's a close up of the wide spacer and other brand of factory rocker arm shaft bolt... You may recognize this "H" marking that signifies it was made by Cold heading... The factory used more than one supplier for the bolts and it's ok to mix them on the same shaft... You can see the three marks on the circle of the bolt to signify that it is also a grade 5 bolt as the other one shown above...
When you set up the shaft, the narrow spacers go on the #1, #3, and #5 bolt positions... The wide spacers go on the #2 and #4 bolt positions on the shaft like this... Always verify that you have the ball sockets of the rocker arms for the pushrods offset to the outboard for each cylinder and the spacers for the bolts alternate starting out with narrow, wide, narrow, wide, narrow for the shaft...
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Installing the rocker arms and shafts...
When you get all of the rocker arms on the shaft, make sure the bolt heads are on the top of the shaft and the oil feed holes in the shaft are downward, it's time to install the assembly on the head... The rocker arms will tend to hang upside down...
Hold the shaft so the valve tip side of the rocker arms are toward the engine and the ball socket side is facing you... Bring the shafts to the side of the valves, contact the valves, then roll the shafts and let the valves turn the rocker arms to the proper position like this...
Valve tips down and let the valves twist the rocker arms as you bring the shaft to the head... Use the valves and springs to catch the rocker arm and rotate it as you install the shaft on the head like shown in the next few pictures... This way you aren't fighting all of the rocker arms separately at one time while trying to install them... It's easier...
Roll the shafts into position...
And down... Houston we have landed...
Make sure that all of the pushrod ends seat properly in the ball socket part of the rocker arm before you tighten them...
There is no adjustment needed for the stamped steel rocker arms... Just torque the shafts and you are done... That is the beauty of the Chrysler stamped steel hydraulic rocker arms...
*************** WARNING *************** WARNING *************** WARNING *************** WARNING ***************
There is an error in some years of the factory service manuals for the rocker arm torque... The incorrect torque is called out at 30 foot pounds and they say the threads are 3/8" x 16... IF YOU TORQUE THEM TO THAT SPEC, YOU WILL STRETCH THE BOLTS AND MAY BREAK THEM...
THE CORRECT TORQUE FOR THE ROCKER ARM BOLT SHAFTS IS 180 - 200 INCH POUNDS...!!!
The 69 Dodge, 69 Plymouth, and the 70 Dodge service manuals state they are 3/8" x 18 bolts and torque to 30 foot pounds... This is not correct and will ruin the bolts if you torque them that much...
This was corrected in the 70 Plymouth and 71 Dodge and Plymouth service manuals and you will see that they are correctly identified as 5/16" x 18 threads in those manuals and torque to 200 inch pounds...
The early 60's service manuals called out 15 foot pounds, which converts to 180 inch pounds and is acceptable, but I would use an inch pound torque wrench instead of a foot pound torque wrench for a torque that low to be accurate...
*************** WARNING *************** WARNING *************** WARNING *************** WARNING ***************
The correct torque for the rocker arm shaft bolts is 200 inch pounds as called out in the 70 Plymouth service manual as shown below... Use an inch pound 3/8" drive torque wrench to torque these as it is too low for a 1/2" drive foot pound torque wrench to be accurate... Remember slow and steady pull always when using a torque wrench to tighten a bolt or nut for accurate torque...
*************************************************************************
Adjustable rocker arms...
Now we will show the adjustable rocker arms... They install mostly the same procedure as the hydraulic rocker arms, but there are a few differences...
Here is a shaft assembly with the adjustable rocker arms... You can see that the rocker shaft bolts have the same narrow and wide spacers under the bolts and the narrow spacers are in the #1, #3, & #5 bolt holes and the wide spacers are in the #2 and #4 bolt holes just like the hydraulic rocker arms... However there is a round spacer that goes between each pair of intake and exhaust rocker arms...
All of the adjustable rocker arms are the same, straight with no offset and can go in any position...
Here they are shown mocked up on a loose head... The angle of the picture makes the outboard rocker arms look offset, but they are actually straight...
From the other side...
Here are the pushrods for the adjustable rocker arms installed in an engine ready for the rocker arms to be installed... You can see the cup ends on the top of the pushrod for the ball of the adjusting stud for the rocker arm to contact...
Here is a close up of the rocker arm with the stud in the cup end on the right side and the left side without the pushrod showing the end of the ball stud that goes into the cup end of the pushrod... The cup is in contact with the bottom of the rocker arm because the stud is not adjusted yet in this picture... When adjusted properly there should be at least 1 1/2 threads or more showing below the rocker arm...
Here I have circled the cup end of the pushrod with the rocker arm stud, and pointing to the ball end of the stud on the other side... Note that these are not adjusted, just put together for illustration purposes.
When installing the adjustable rocker arm shafts to the head, use the same procedure as explained above for the hydraulic non-adjustable (stamped steel) rocker arms... Back off the adjusting studs before installing the rocker arms like the one in the picture above so they do not bind... Torque the rocker arm shaft bolts to the same torque as the stamped steel rocker arms...
Put the valve tips down and roll them over the springs until you seat the shaft on the rocker shaft bosses in the head, just like the procedure for the stamped steel rocker arms as described above... Make sure that all of the rocker arm ball stud ends are properly seated in the cup end of the pushrod before torqueing... Tighten to 200 inch pounds with a 3/8" drive torque wrench with a slow and steady pull...
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Now to adjust the rocker arms...
On a solid lifter cam, look up the proper specs for the proper year and engine that you are adjusting for a stock engine, or contact the manufacturer of the cam that you have installed if you are running aftermarket solid cam and/or aftermarket rocker arms... Many times the intake and exhaust valves are different clearances, the exhaust valves usually have more clearance...
When you adjust a valve, the cam must be on the base circle of the lobe so the lifter is not on the nose of the lobe to adjust it... That way the valve is closed and there isn't pressure on the valve... Since we have the intake manifold off, it's easy to see the cam and the lobe for the valve that we are working on... Rotate the crank so the both valves are closed for the cylinder that you are working on... Watch for the intake valve to close as that is where both valves for that cylinder will be on the base circle...
Take a feeler gauge with the proper thickness and place it between the rocker arm and valve stem... Tighten the adjusting stud on the rocker arm while rotating the pushrod... When the pushrod won't rotate with the feeler gauge between the valve stem and rocker arm, back it off a smidgeon until you can rotate the pushrod with some resistance... Then repeat with the proper clearance for the other valve... Repeat for each cylinder making sure that you rotate the crank until both valves are closed (just after the intake valve closes) and you are not on base circle for that lobe...
For a hydraulic cam with adjustable lifters, contact the cam and/or lifter manufacturer for the proper adjustment procedure...
If you adjust the valves too loose, you won't get full lift and duration for your cam and you won't get the maximum power and efficiency out of your engine... If they are adjusted too tight, the valve may not close all the way and will cause low cylinder pressure and a valve may hit a piston and damage a piston or the whole engine in extreme cases... So it is important to have your valves adjusted properly...
Here are the clearance specs for a factory 67 273 with solid lifters and adjustable rocker arms...
When the valves are properly adjusted, there should be 1 1/2 to 3 threads showing below the rocker arm... Also rotate the crank a few turns and watch the valve open and close for each cylinder to make sure the spring doesn't contact the rocker arm during movement, I've seen this happen and had to grind some clearance to keep the valve spring from rubbing the bottom of the rocker arm while opening and closing the valve...
This is what it should look like when everything is done...
Now you are this far, cover the engine until you work on it to keep it clean and free of any loose parts that may be falling... Set the intake manifold and valve covers on the engine and put a rag in the distributor hole to keep things out...
Next we will move onto preparing the timing chain cover...
How to Rebuild a Small Block Part 14: Preparing the Timing Chain Cover
