Rocker Stands For Magnum Valve Train??

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The pattern is deceptive. What hughes told you should be happening. The rocker should start on the valley side offcenter, at mid-lift be exh port side offcenter, and then at max lift be back where you started. The rocker follows an arc and mid lift should be the farthest point towards the exh side. That rocker needs to go up IMO. Because you start inside and never come back. So you're never reaching the 90° perpendicular point between rocker and valve stem. That means lost lift at the valve (very small amount) but much more important is you're side-loading the stem. It places more stress on rockers and wears out guides quickly. Studs may need to be longer and watch your valve cover baffles.
 
moper said:
The pattern is deceptive. What hughes told you should be happening. The rocker should start on the valley side offcenter, at mid-lift be exh port side offcenter, and then at max lift be back where you started. The rocker follows an arc and mid lift should be the farthest point towards the exh side. That rocker needs to go up IMO. Because you start inside and never come back. So you're never reaching the 90° perpendicular point between rocker and valve stem. That means lost lift at the valve (very small amount) but much more important is you're side-loading the stem. It places more stress on rockers and wears out guides quickly. Studs may need to be longer and watch your valve cover baffles.
Click to expand...

Moper,

I raised the rocker on the stud over 3/4 of an inch in small increments and the tip never did what you are saying that it should. Dave at hughes said on the magnum head this normally happens with between .650-.700 of lift and his reasoning was that the stud is too close to the spring and if it was moved out a bit toward the intake or valley then it would be more likely to happen...........???????? I will look at it again and measure the amount of lift I am getting, but I am sure that it just will not happen I checked for over an Hour.

Where would you purchase a longer stud?? It would need to be at least 1.25 inches bigger I am guessing because 3/4 of an inch did nothing??
 
Moper,

Ok, I looked at it again and there is no way that by raising the rocker it will change the way that it sweeps across the valve tip like explained earlier.
The rocker stud is angled toward the spring and valve so as you raise it, the problem gets even worse. Maybe the rockers I am using are a pieces of S&^%$!!tt, they are totally based on the SB chevy I guess like most of them out there. Just another reason for me to HATE the Magnum Valve Train set up...........LA all the way from now on!!!!!!!!! It makes me wonder if when the studs were re drilled and tapped and the pad machined down a bit that it was done on the correct angle........???????? Do you have a picture of a Magnum head with the stud in place so I can see the angle of your stud compared to the spring and valve. If it was off only a little bit, by the time you go up the stud it could be quite a bit off and the geometry would never be correct no matter what I do........I am scratching my head now, thinking that is the problem for sure........I need to find out!!
 
the red line is the 90* the yellow is an exaggerated view of where the stud looks like its going.

IMG_0537.jpg
 
Pic is stock magnum. Looks like the holes are perpendicular to the rocker stand on them. 360's right. I missed that in the pic. Maybe it's just the picture. Do the bases of the studs sit flush to the stand on others? Maybe check with a light. If the arc isnt changed by raising the height of the rocker fulcrum point centerline something is off. Have you tried lowering the rocker on the stud?

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I totally understand what you are saying......and it makes alot of sense. So you are thinking that the pad is square but the tap job on the stud is off??

Just got off the phone with Bobby, he says that the angle is correct and that ALL MAGNUM head studs are angled toward the valve and springs.

I need a picture of a stock head assembled ..........anybody??
 
That pic I just took. Stock redon e mangums I plan to use with a factory bolt. The aluminum gage is not machined perfectly 90° tho... but it looks to me lik the hole is 90° to the pad... the pad might be leaned a little, but the stud should come straight out if they are like my factory ones.
 
moper said:
Pic is stock magnum. Looks like the holes are perpendicular to the rocker stand on them. 360's right. I missed that in the pic. Maybe it's just the picture. Do the bases of the studs sit flush to the stand on others? Maybe check with a light. If the arc isnt changed by raising the height of the rocker fulcrum point centerline something is off. Have you tried lowering the rocker on the stud?
Click to expand...

Moper,

Yes the base sits flush, but those were machined also so I cant tell if it was done correctly in relationship to the factory casting. I have done EVERYTHING that I could think of. It is down as far as it can go now without falling off the valve tip toward the intake-valley and this is on the base of the cam where it starts at 0 lift.

I do believe that something is truly wrong the more that I stare at it.

Trying to stay calm and not flip out just yet!
 
Take a breath. This is normal when working with unfamiliar stuff. The up side is you're looking into it. As Bobby did the work, I think he should be the one most invested in the set up. He may know something we dont.
 
I have a set of clearwater 5.9 magnum heads off my car now. No machine work done and still have factory pedestals. I have to go to a school meeting but I will pull them out when I get back and try to get some pics up for you.
 
oops didn't see that moper already did that. I guess the pics won't be needed. I am watching this closely since I will be in the same boat in a month or too. I aslo am thinking about ditching the magnum setup for shaft mount again. Seems like a much easier setup to deal with.
 
Mad Dart said:
I totally understand what you are saying......and it makes alot of sense. So you are thinking that the pad is square but the tap job on the stud is off??

Just got off the phone with Bobby, he says that the angle is correct and that ALL MAGNUM head studs are angled toward the valve and springs.

I need a picture of a stock head assembled ..........anybody??
Click to expand...
looks like its angled away from it.
 
moper said:
Pic is stock magnum. Looks like the holes are perpendicular to the rocker stand on them. 360's right. I missed that in the pic. Maybe it's just the picture. Do the bases of the studs sit flush to the stand on others? Maybe check with a light. If the arc isnt changed by raising the height of the rocker fulcrum point centerline something is off. Have you tried lowering the rocker on the stud?
Click to expand...


Moper,

If you know your installed height on the retainer or the top of the valve and then straight edge off the top of the valve or retainer across to the stud and get a measurement from center of the valve to center of stud, that just might explain everything?? I know the valve is where it needs to be, it has to be the stud!



Thanks in advance for your help.
 
moper said:
Take a breath. This is normal when working with unfamiliar stuff. The up side is you're looking into it. As Bobby did the work, I think he should be the one most invested in the set up. He may know something we dont.
Click to expand...


Contact has been made waiting for his response.
 
Here are some pics I took. On the stock setup with the 5/16 bolt about level with the valve tip I got right a 1 3/8". looks like the pedestal should have a 10 degree tilt in relation to the head sitting on a flat surface. sorry for the quality. My camera is having focusing issues.....I need a new one. The angle finder is on 10 degrees since you can't see it.

Picture 001 (Medium) (2).jpg


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Picture 003 (Medium) (2).jpg


Picture 004 (Medium) (2).jpg


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Picture 007 (Medium).jpg
 
Dartman,

I asked Moper the same question below.......Thanks for the pictures!

If you know your installed height on the retainer or the top of the valve and then straight edge off the top of the valve or retainer across to the stud and get a measurement from center of the valve to center of stud, that just might explain everything?? I know the valve is where it needs to be, it has to be the stud!

Thanks in advance for your help.
 
I'm not sure about the installed height of my spring I believe they are stock config. From the center of the valve to the center of the stud I used a caliper and measured it at 1 5/16"
 
63dartman said:
I'm not sure about the installed height of my spring I believe they are stock config. From the center of the valve to the center of the stud I used a caliper and measured it at 1 5/16"
Click to expand...

That is at the top of the valve where you got this measurement correct?
 
Yes, I went from the center of the valve stem to the bolt center. Well as close to center as my eyes could see:) Also I ran the bolt down until it was straight across from the valve stem. In the picture it's not down where I took the measurement.
 
Post a pic of the push rod /rocker cup angle at closed and full lift and compare, measure lift at retainer and compare to the degree.

Unless you are losing a lot of lift, the roller is gonna save it from guide shoving friction, as opposed to a non roller dragging across it.jmo
 
I just went out and pulled out one of my Iron ram heads and measured it and came up with exactly the same measurements 63Dartman got. The stud is angled towards the valve 10 degrees and I measured 1.315 (1-5/16") center to center of the valve tip and stud.

I was thinking the same thing wild one said that since you have roller tip rockers they aren't going to scrub across the valve tip creating side loading.

Here's a picture of mine showing the angle.

Magnum head valve to rocker stud angle.jpg
 
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