Don Terrill’s Speed-Talk

Paul Kane, one of the politicians on this board. If the facts don't fit, you make them fit. Especially if you have an agenda.

"kim, you are now arguing how the roller wheel is positioned atop the valve, not where the roller wheel is positioned atop the valve."

So now you're saying that when you twist the rocker it doesn't move the position on top of the valve stem.... Ok, we're done here.

Since you're into Miller rockers so much, why don't you adress my remarks on Millers quality issues? They are easily searched on google.

kimosabi wrote:Paul Kane, one of the politicians on this board. If the facts don't fit, you make them fit. Especially if you have an agenda.

"kim, you are now arguing how the roller wheel is positioned atop the valve, not where the roller wheel is positioned atop the valve."

So now you're saying that when you twist the rocker it doesn't move the position on top of the valve stem.... Ok, we're done here.

Since you're into Miller rockers so much, why don't you adress my remarks on Millers quality issues? They are easily searched on google.

Give it a rest.

Almost everyone reading this knows that he was talking about the inside/outside contact roll pattern; (with the rocker arm being aligned correctly to the valve).
If not ... of course there are all sorts of other variables introduced. That is no longer a rocker arm issue.

I've used the miller PVS stud mount rockers on a SBF for several years now, very happy with them. 8000 rpm 302 based, mid 5's in the 1/8. The mid-lift theory worked out very well, cam lobe info transfers to the valve tip accurately.

kimosabi wrote:So now you're saying that when you twist the rocker it doesn't move the position on top of the valve stem....

kim you are not looking at the roller wheel's relation to the valve stem, instead you're moving the entire rocker arm in relation to the valve train. You're completely changing the setup. Fine, go ahead if you want. You may position the rocker arm however you wish for the sake of example, just let the roller wheel fall wherever it may atop the valve stem and don't worry whether it's inboard, outboard, dead center, etc, because the roller wheel's position atop has nothing to with your final geometry setup. And that's true whether your rocker arm is installed straight, pidgeon-toed, inline valve train or compound valve angles such as in a canted valve head. I've tried numerous ways now to explain this to you, sorry you don't comprehend it. I'm not going to spend any more time explaining--there are plenty of examples in this thread that you may re-read if you want.

kimosabi wrote:Since you're into Miller rockers so much, why don't you adress my remarks on Millers quality issues? They are easily searched on google.

kim, use a little rationale: Every rocker arm manufacturer has a history of failed rocker arms. You are less likely to see the history of broken Crane rockers (for example) on a google search because millions of Crane rockers have been sold and so the links about broken Cranes are buried amongst near-endless pages of links discussing Crane rockers. Incidentally, most broken rocker arms--regardless of brand--"failed" because something else failed in the engine and took the rocker arm out along the way, or user error. A rocker arm breaking entire unto itself is the lowest percentage of occurrence, and that's certainly true about Millers as much as any other brand.

I'll be moving along now.

Well reguardless they are going on Trackboss #1. I'll keep you posted with developments!!

kimosabi wrote:
I'll be moving along now.

Thank God! My head hurts.

Walter R. Malik wrote:

kimosabi wrote:Paul Kane, one of the politicians on this board. If the facts don't fit, you make them fit. Especially if you have an agenda.

"kim, you are now arguing how the roller wheel is positioned atop the valve, not where the roller wheel is positioned atop the valve."

So now you're saying that when you twist the rocker it doesn't move the position on top of the valve stem.... Ok, we're done here.

Since you're into Miller rockers so much, why don't you adress my remarks on Millers quality issues? They are easily searched on google.

Give it a rest.

Almost everyone reading this knows that he was talking about the inside/outside contact roll pattern; (with the rocker arm being aligned correctly to the valve).
If not ... of course there are all sorts of other variables introduced. That is no longer a rocker arm issue.

Yeah I'll give it a rest. What I have been trying to do is to help Paul Kane understand that geometry applies one way or the other. It always does. Blunt statements like "geometry does not involve roller tip placement on the valvestem" is only half correct.

Anyhoo, good luck and have fun with your build OP! If you have a shelf roller rocker and compare it to the Miller rocker and post a pic of the two would be cool.

Wow. Amazing that people still employ the 'if I don't understand, it must be wrong" attitude. Smh.

midnightbluS10 wrote:Wow. Amazing that people still employ the 'if I don't understand, it must be wrong" attitude. Smh.

I used ONE set of 1.6 SBC rockers. I thought this was a great idea I have always struggled with rocker are geometry. Five passes (1/8 mile drag) the engine dropped a valve, the pin that holds roller on came out. After inspection the pins had moved on five other rockers. I called Miller he told me " I thought I had that problem fixed" well short story I fix the customer's engine on my dime. I would not use them.

mdengine wrote:I used ONE set of 1.6 SBC rockers. I thought this was a great idea I have always struggled with rocker are geometry. Five passes (1/8 mile drag) the engine dropped a valve, the pin that holds roller on came out. After inspection the pins had moved on five other rockers. I called Miller he told me " I thought I had that problem fixed" well short story I fix the customer's engine on my dime. I would not use them.

Agreed they do seem to have a history of failure. Internet searching reveals multiple rocker failures for every part of the rocker. I have little time or money to waste so I will continue to use a steel stud mount rocker from Comp or Crower over any aluminum rocker arm.

Mr Kimosabi I am about to set up T&D rocker arms on a pair of Brodex LS heads. I am perty sure the T&D
Rockers are designed to run on the mid lift theory.
How would you suggest I set them up??

jed wrote: ↑Wed Nov 01, 2017 8:59 pm Mr Kimosabi I am about to set up T&D rocker arms on a pair of Brodex LS heads. I am perty sure the T&D
Rockers are designed to run on the mid lift theory.
How would you suggest I set them up??

I would use the set up tool that comes with the T&D.
reed

"At this day and age I don't know that manufacturing rocker arms is outlandishly easier in aluminum than steel. But as far as attributes of steel vs aluminum in general, off the top of my head mass moment of inertia may be better with certain designs in aluminum over steel. Aluminum also dissipates heat much faster than steel (it absorbs heat faster and disipates it faster). "


Aluminum rockers are basically sawed from bar stock already extruded to shape and any monkey with a 3 axis knee mill in his garage can do the machining. There is no comparison in terms of ease of manufacturing between steel rockers and aluminum.
A well designed steel rocker will have substantially better fatigue resistance, have a lower MOI compared to aluminum and be more rigid. Steel rocker will always win on the spintron.
Been building race engines for 28 years, I have never had a heat related failure with a rocker arm.

Agree, use steel for rocker arms. Why take a chance?