Exhaust rocker geometry question

[63409impala]

And half lift if I had to guess. (Don't have a dial indicator)

 

[63409impala]

And here is at rest, mid lift and full lift with a 9.050 pushrod.

 

[63409impala]

And there is a .054 gap between the stud boss and the rocker stud. I'd love to get the rocker all the way down

 

[La Hot Rods]

That push rod looks way to short to me.

 

[63409impala]

I'd say yes as well. But anything longer and the roller is more on the edge. Like this. I did have a 9.400 in it.

 

[63409impala]

And thats with a lash cap.

 

[La Hot Rods]

Re move the lash cap and that it to half lift.

 

[63409impala]

No difference. Still on extreme edge of valve

 

[63409impala]

As requested

 

[La Hot Rods]

You still need longer push rod.

 

[63409impala]

Correct me if I'm wrong, but any longer won't it push the tip of the rocker even farther towards the edge than it already is? Isn't that what you try to avoid?

 

[La Hot Rods]

I see what is happening now.
With the angle of the valve pointing toward the rocker stud. The farther up you go the center line of the valve and the rocker stud get closer together. So now we want to drop the rocker down with a shorter push rod, but now the pivot shaft center line is now to low to get to a 90 angle needed at half lift.
If you don't need the longer valve stem a shorter valve may be the best fix or the rocker stud need to move away from the valve.

I know it hard to tell from a picture, but are the push rods seated in the rocker arm? I only ask because the push rod look real close to the center of the rocker to me.

 

[63409impala]

Yes. They're seated. It needed the longer valve to avoid coil bind.

 

[La Hot Rods]

Are these rocker arms for a 409?

 

[Gofish]

I’m with La... I’m wondering if those are the correct rockers.

John

 

[63409impala]

They're a 1.7 bbc rocker. Surely I can't be the only person alive using these things on a 409

 

[La Hot Rods]

I have been running Crane Gold 1.7 big block.
Have you tried this on a different valve?

 

[63409impala]

No.

 

[La Hot Rods]

If you notice in the picture you posted, the ones with the shorter push rods the roller tip wipes most all the way across the valve tip. Now if you look at the one with the longer push rod the wipe pattern gets shorter and would get a little shorter with even longer, but it is moving to the edge of the valve tip. The shorter the wipe the better.
In my opinion your combination is not going to work happy. I'll have to think what could be fix without reinventing the wheel.

 

[63409impala]

The combo is this for valvetrain. Crane .655 lift solid roller cam, crower 409 chevrolet solid roller linkbar lifters, trend pushrods, .100 longer valves and a 1.7 ratio big block chevrolet rocker. Surely someone else has had to of run into this issue. I can't be the only one