Speedmaster rockers

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Ok, I’m massively disappointed. First, IF your rockers have the oil hole in the rocker clocked where Chrysler put it then you use the 9/32 inch measurement. So it’s about .281 and it is plus zero minus .050 not the other way around.

The only rockers I have on hand are the MP aluminum rockers. They are the same as the Crane gold rockers just blue. I had no idea until I dug these out that they have the oil hole lowered in the rocker body. I don’t know if Crane did that or Chrysler. Either way, it sucks because you can’t use the 9/32 measurement.

When looking at these pictures you’ll see there is an undercut area on the adjuster. That undercut and where it is relative to the oil feed hole in the rocker is critical.

In theory, while the valves are on the seat and there is lash in the rocker there is going to be oil blowing out of the hole in the rocker, hitting the undercut and running down into the cup. This is all predicated on some things. One is at idle and low engine speeds you have enough oil volume and pressure at the rocker to get the oil to blow out of the hole and onto the adjuster. Low volume/pressure at idle won’t feed the bulldog. You will smoke adjusters. And here is the big issue (as if the flow and pressure thing wasn’t bad enough) the hole in the rocker MUST and by MUST I mean ABSOLUTELY MUST line up with the hole in the shaft or you will have issues.

If you are running a SFT cam with low spring pressure this isn’t usually a thing. But a solid roller and some decent spring pressure and it is critical. And you might be surprised that many times the hole in the rocker is never lined up with the hole in the shaft.

Going further down the rabbit hole...the only way I know to correct the hole alignment between the rocker and the shaft is to mock everything up like it’s going to run. Use machinists blueing on the shafts. Then bolt the shaft and rockers on the head, lined up side to side and with the geometry corrected (the lined up and geometry corrected is important) and take a sharp scribe and stick it in the oil hole in the rocker and mark the shaft where the hole in the rocker is. Then you have to take all that apart, get a really sharp carbide center drill or something similar and drill the hole in the shaft where it goes.

Ok, back to adjuster protrusion. If you have rockers where the oil feed hole is right at the bottom of the threads then use the 9/32 measurement. If the hole is lower than the bottom of the threads you have to eyeball the protrusion. Yes, it’s stupid. That lowered hole was done (as told to me by Chase Knight at Crane) that that was done because everyone was running pushrods too short so the lowered the hole to stop smoking adjusters. Don’t tell people how to fix it. Just drop the hole. And that’s bad because even though it’s a relatively small amount, it does change the rocker ratio. The further out the adjuster is, the further it is away from the center of the shaft and that changes the ratio. So it’s a suck suck deal. Now to the pictures.
A0B568A5-C312-44D9-B202-8A84CCE741F3.jpeg

I’m starting with this picture because you can see by the arrows pointing to the black sharpie dot where the oil feed hole SHOULD be. In fact, it should be up a bit more but that’s as good as I could get with a sharpie. It really should break through right at the bottom of the threads.

If the hole was in that location, the 9/32 measurement is the correct measurement to use. Since the hole in this rocker is lower than it should be, the 9/32 measurement is wrong. You have to eyeball the protrusion.

796493E6-D689-42C0-9E40-D388CD5A0A08.jpeg


In this picture you can see how far out the adjuster is. This is because the oil feed hole is so low in the rocker. That adjuster is about .375 out. That would smoke adjusters if the oil hole was in the correct location.
796493E6-D689-42C0-9E40-D388CD5A0A08.jpeg

^^^Double picture^^^

7CDEA0A9-B352-4978-8BEB-ED27D403CE0D.jpeg


This picture shows the 9/32 protrusion and this is what you use IF the oil hole is at the bottom of the threads. In the pictures you can see the undercut area and that’s what you want to get in the correct position so oil coming out of the rocker hits that undercut and runs down into the cup.

One can argue that this system is Rube Goldberg through and through you wouldn’t be wrong. But it does work IF the hole in the rocker lines up with the hole in the shaft while the valves are in the seat and the adjuster is correctly positioned according to where the oil feed hole in the rocker is.

I hope everyone isn’t confused on this, but once you understand the relationship of the hole in the rocker to the undercut on the adjuster. If you get everything right, this system will oil the adjusters to well over 8500 rpm with 900 pounds of spring pressure over the nose.
BB21F1FA-FFAE-4291-ADBF-E428BE4F505A.jpeg



Here is a picture of 4 pushrods. I don’t have any single or double taper pushrods in the shop. I thought I had some single tapers out there but I can’t find them.

From the bottom is an OE pushrod which is good for dead stock stuff only. After that, but something better.

Second from the bottom is a Smith Brothers 3/8 heavy wall pushrod. This is a good pushrod for what it is. A SFT cam should be able to use these unless it’s a W2 head. The double offset of the lifter bank angle and rocker offset of W2 will push these to the limit.

The top 2 pushrods are Smith Brothers heavy wall 7/16 pieces. These are good pushrods. You can see by the arrows that these have been under duress. The round mark is from the pushrod bending (yup...it sure did bend) and in bending it was rubbing the head at Max lift. There was over .125 clearance where it was rubbing and it moved that far. This was an intake pushrod.

The hash marks the other pushrod are from a lifter failure and the link bar came around and beat the crap out of the pushrod. The lifter failed on an intake lobe and that pushrod was on an exhaust.

Probably way too much information but it’s all important. You have to set adjuster protrusion by where the oil feed hole is. I believe on your Norris rockers the oil hole is right at the threads where it should be. If that’s the case, it’s 9/32 minus .050 plus zero.

If your oil feed hole is lower than the bottom of the threads you have to set adjuster protrusion so the undercut is lined up with the hole in the rocker.

One other thing to note is once you get to a 3/8 pushrod you start getting into clearance issues. A 7/16 pushrod is worse. Especially at the bottom of the pushrod tunnel. You may have to grind out enough materiel from the tunnel that you break through the intake flange. If that’s what it takes it’s ok. A single taper 7/16-3/8 will make fitting the pushrod a bit easier and the 3/8-7/16 double taper gets you the same clearance through the tunnel with the extra diameter of 7/16 in the middle.
 
Wow: That is the clearest easiest to understand
explanation that I have ever read on this.

All I every do is confuse the heck out of people!
 
I got confused after reading the first paragraph... soooo when I need pushrods, I'll just ask which ones to buy lol.
 
I got confused after reading the first paragraph... soooo when I need pushrods, I'll just ask which ones to buy lol.


I am massively disappointed because I never looked at those rockers as close as I did today. That’s when I saw the funky oil hole location.
 
Gimme cup adjusters and pushrod oiling. Short n sweet:lol:
 
Ok, I’m massively disappointed. First, IF your rockers have the oil hole in the rocker clocked where Chrysler put it then you use the 9/32 inch measurement. So it’s about .281 and it is plus zero minus .050 not the other way around.

The only rockers I have on hand are the MP aluminum rockers. They are the same as the Crane gold rockers just blue. I had no idea until I dug these out that they have the oil hole lowered in the rocker body. I don’t know if Crane did that or Chrysler. Either way, it sucks because you can’t use the 9/32 measurement.

When looking at these pictures you’ll see there is an undercut area on the adjuster. That undercut and where it is relative to the oil feed hole in the rocker is critical.

In theory, while the valves are on the seat and there is lash in the rocker there is going to be oil blowing out of the hole in the rocker, hitting the undercut and running down into the cup. This is all predicated on some things. One is at idle and low engine speeds you have enough oil volume and pressure at the rocker to get the oil to blow out of the hole and onto the adjuster. Low volume/pressure at idle won’t feed the bulldog. You will smoke adjusters. And here is the big issue (as if the flow and pressure thing wasn’t bad enough) the hole in the rocker MUST and by MUST I mean ABSOLUTELY MUST line up with the hole in the shaft or you will have issues.

If you are running a SFT cam with low spring pressure this isn’t usually a thing. But a solid roller and some decent spring pressure and it is critical. And you might be surprised that many times the hole in the rocker is never lined up with the hole in the shaft.

Going further down the rabbit hole...the only way I know to correct the hole alignment between the rocker and the shaft is to mock everything up like it’s going to run. Use machinists blueing on the shafts. Then bolt the shaft and rockers on the head, lined up side to side and with the geometry corrected (the lined up and geometry corrected is important) and take a sharp scribe and stick it in the oil hole in the rocker and mark the shaft where the hole in the rocker is. Then you have to take all that apart, get a really sharp carbide center drill or something similar and drill the hole in the shaft where it goes.

Ok, back to adjuster protrusion. If you have rockers where the oil feed hole is right at the bottom of the threads then use the 9/32 measurement. If the hole is lower than the bottom of the threads you have to eyeball the protrusion. Yes, it’s stupid. That lowered hole was done (as told to me by Chase Knight at Crane) that that was done because everyone was running pushrods too short so the lowered the hole to stop smoking adjusters. Don’t tell people how to fix it. Just drop the hole. And that’s bad because even though it’s a relatively small amount, it does change the rocker ratio. The further out the adjuster is, the further it is away from the center of the shaft and that changes the ratio. So it’s a suck suck deal. Now to the pictures.
View attachment 1715894534
I’m starting with this picture because you can see by the arrows pointing to the black sharpie dot where the oil feed hole SHOULD be. In fact, it should be up a bit more but that’s as good as I could get with a sharpie. It really should break through right at the bottom of the threads.

If the hole was in that location, the 9/32 measurement is the correct measurement to use. Since the hole in this rocker is lower than it should be, the 9/32 measurement is wrong. You have to eyeball the protrusion.

View attachment 1715894535

In this picture you can see how far out the adjuster is. This is because the oil feed hole is so low in the rocker. That adjuster is about .375 out. That would smoke adjusters if the oil hole was in the correct location.
View attachment 1715894535
^^^Double picture^^^

View attachment 1715894541

This picture shows the 9/32 protrusion and this is what you use IF the oil hole is at the bottom of the threads. In the pictures you can see the undercut area and that’s what you want to get in the correct position so oil coming out of the rocker hits that undercut and runs down into the cup.

One can argue that this system is Rube Goldberg through and through you wouldn’t be wrong. But it does work IF the hole in the rocker lines up with the hole in the shaft while the valves are in the seat and the adjuster is correctly positioned according to where the oil feed hole in the rocker is.

I hope everyone isn’t confused on this, but once you understand the relationship of the hole in the rocker to the undercut on the adjuster. If you get everything right, this system will oil the adjusters to well over 8500 rpm with 900 pounds of spring pressure over the nose.
View attachment 1715894546


Here is a picture of 4 pushrods. I don’t have any single or double taper pushrods in the shop. I thought I had some single tapers out there but I can’t find them.

From the bottom is an OE pushrod which is good for dead stock stuff only. After that, but something better.

Second from the bottom is a Smith Brothers 3/8 heavy wall pushrod. This is a good pushrod for what it is. A SFT cam should be able to use these unless it’s a W2 head. The double offset of the lifter bank angle and rocker offset of W2 will push these to the limit.

The top 2 pushrods are Smith Brothers heavy wall 7/16 pieces. These are good pushrods. You can see by the arrows that these have been under duress. The round mark is from the pushrod bending (yup...it sure did bend) and in bending it was rubbing the head at Max lift. There was over .125 clearance where it was rubbing and it moved that far. This was an intake pushrod.

The hash marks the other pushrod are from a lifter failure and the link bar came around and beat the crap out of the pushrod. The lifter failed on an intake lobe and that pushrod was on an exhaust.

Probably way too much information but it’s all important. You have to set adjuster protrusion by where the oil feed hole is. I believe on your Norris rockers the oil hole is right at the threads where it should be. If that’s the case, it’s 9/32 minus .050 plus zero.

If your oil feed hole is lower than the bottom of the threads you have to set adjuster protrusion so the undercut is lined up with the hole in the rocker.

One other thing to note is once you get to a 3/8 pushrod you start getting into clearance issues. A 7/16 pushrod is worse. Especially at the bottom of the pushrod tunnel. You may have to grind out enough materiel from the tunnel that you break through the intake flange. If that’s what it takes it’s ok. A single taper 7/16-3/8 will make fitting the pushrod a bit easier and the 3/8-7/16 double taper gets you the same clearance through the tunnel with the extra diameter of 7/16 in the middle.
That's a lot of great information and I appreciate it. I should probably give you more info about my combination. I'm running W2 Econo heads which I believe are 810 castings. Banana groove rocker shafts with the previously mentioned Norris stainless roller rockers, 1.6 ratio. For cam I'm running a Comp Cams solid roller, gross lift is .654 intake, .655 exhaust, duration @ .050 is 269 intake, 276 exhaust, installed at 106.0 intake center line. Comp Cams roller lifters. I currently have Smith Brothers 3/8 diameter pushrods with .120 wall thickness, no oil hole, length currently is 7.4375, or 7 7/16s.
If I'm interpreting your info correctly I shouldn't be running 3/8s push rods with these W2 Econo heads, but 7/16s? I don't have any clearance issues with the 3/8s as it appears the push rod holes in these heads have been enlarged.
I'll have to take a look at these Norris rockers to check the location of the oil hole in relation to the adjuster threads. I'll do that when I get home from work today. I also know that the adjusters are turned down more than your calculations show to get proper valve lash settings, which led me to believe that the push rods I am currently using are too short. I'll post a picture of one this evening.
 
That's a lot of great information and I appreciate it. I should probably give you more info about my combination. I'm running W2 Econo heads which I believe are 810 castings. Banana groove rocker shafts with the previously mentioned Norris stainless roller rockers, 1.6 ratio. For cam I'm running a Comp Cams solid roller, gross lift is .654 intake, .655 exhaust, duration @ .050 is 269 intake, 276 exhaust, installed at 106.0 intake center line. Comp Cams roller lifters. I currently have Smith Brothers 3/8 diameter pushrods with .120 wall thickness, no oil hole, length currently is 7.4375, or 7 7/16s.
If I'm interpreting your info correctly I shouldn't be running 3/8s push rods with these W2 Econo heads, but 7/16s? I don't have any clearance issues with the 3/8s as it appears the push rod holes in these heads have been enlarged.
I'll have to take a look at these Norris rockers to check the location of the oil hole in relation to the adjuster threads. I'll do that when I get home from work today. I also know that the adjusters are turned down more than your calculations show to get proper valve lash settings, which led me to believe that the push rods I am currently using are too short. I'll post a picture of one this evening.


If you don’t mind, can you take a close up picture of the oil feed hole? I’m pretty sure Norris put the hole where it should be and we can compare the two oil hole locations.

As far as pushrods go, the Chrysler stuff doesn’t follow the same rules as other engines.

For one thing, on the SB you have the 59 degree lifter bank angle so the lifter doesn’t even push the pushrod in a straight line. Any time you have a column (say a pushrod for example) in compression and you have the load not running through its axis (centerline) then that column loses some of its old carrying capabilities.

Now add to that the roughly .800 offset for the W2 rocker and you have a column under compression load out of plane in two directions.

I can’t remember exactly where I found the math to calculate how much reduction there is in load carrying when you are out in two planes but it was quite a bit.

That’s why all the pushrod manufacturers think you can use what you’d use in a small block Chevy and it just isn’t so.

That’s why when I read that you have adjusters backing off the first thing I thought of was pushrods. Even if you can’t see witness marks where the pushrods are bending and touching something doesn’t mean it isn’t happening. Your pushrods are most likely doing something similar to pole vaulting. It bends under initial loading and at some point it has to return to its original state. That bending and unbending has stored energy and it has to go somewhere.

One interesting thing I noted when I finally got the pushrods stiff enough was the engine was quieter but the lash was more audible. The constant loading and unloading of the pushrods was making a noise that you wouldn’t know if you didn’t stop it. Once the pushrods got stiffer, that peculiar sound went away and the lash became more pronounced.
 
If you don’t mind, can you take a close up picture of the oil feed hole? I’m pretty sure Norris put the hole where it should be and we can compare the two oil hole locations.

As far as pushrods go, the Chrysler stuff doesn’t follow the same rules as other engines.

For one thing, on the SB you have the 59 degree lifter bank angle so the lifter doesn’t even push the pushrod in a straight line. Any time you have a column (say a pushrod for example) in compression and you have the load not running through its axis (centerline) then that column loses some of its old carrying capabilities.

Now add to that the roughly .800 offset for the W2 rocker and you have a column under compression load out of plane in two directions.

I can’t remember exactly where I found the math to calculate how much reduction there is in load carrying when you are out in two planes but it was quite a bit.

That’s why all the pushrod manufacturers think you can use what you’d use in a small block Chevy and it just isn’t so.

That’s why when I read that you have adjusters backing off the first thing I thought of was pushrods. Even if you can’t see witness marks where the pushrods are bending and touching something doesn’t mean it isn’t happening. Your pushrods are most likely doing something similar to pole vaulting. It bends under initial loading and at some point it has to return to its original state. That bending and unbending has stored energy and it has to go somewhere.

i'll take some photos when i get home this afternoon and post them.

One interesting thing I noted when I finally got the pushrods stiff enough was the engine was quieter but the lash was more audible. The constant loading and unloading of the pushrods was making a noise that you wouldn’t know if you didn’t stop it. Once the pushrods got stiffer, that peculiar sound went away and the lash became more pronounced.
 
If you don’t mind, can you take a close up picture of the oil feed hole? I’m pretty sure Norris put the hole where it should be and we can compare the two oil hole locations.

As far as pushrods go, the Chrysler stuff doesn’t follow the same rules as other engines.

For one thing, on the SB you have the 59 degree lifter bank angle so the lifter doesn’t even push the pushrod in a straight line. Any time you have a column (say a pushrod for example) in compression and you have the load not running through its axis (centerline) then that column loses some of its old carrying capabilities.

Now add to that the roughly .800 offset for the W2 rocker and you have a column under compression load out of plane in two directions.

I can’t remember exactly where I found the math to calculate how much reduction there is in load carrying when you are out in two planes but it was quite a bit.

That’s why all the pushrod manufacturers think you can use what you’d use in a small block Chevy and it just isn’t so.

That’s why when I read that you have adjusters backing off the first thing I thought of was pushrods. Even if you can’t see witness marks where the pushrods are bending and touching something doesn’t mean it isn’t happening. Your pushrods are most likely doing something similar to pole vaulting. It bends under initial loading and at some point it has to return to its original state. That bending and unbending has stored energy and it has to go somewhere.

One interesting thing I noted when I finally got the pushrods stiff enough was the engine was quieter but the lash was more audible. The constant loading and unloading of the pushrods was making a noise that you wouldn’t know if you didn’t stop it. Once the pushrods got stiffer, that peculiar sound went away and the lash became more pronounced.
As you can see, the oil holes on my Norris rockers are in the correct location. Also including a picture of an adjuster at its correct lash position.
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20220324_164935.jpg
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20220324_165032.jpg
 
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