Rocker arm geometry

[Joachim]

Hi gents. I am in the process of re-assembling my engine. Due to a few changes (PW3, milled head, no base gasket) I saw the need to adjust the push rod length. I got myself an adjustable push rod. I understand that the consensus is to achieve central push on the valve at mid lift. For normal road use at least. I was able to achieve that for both inlet valves with taking 2.2mm off the push rods:

https://photos.app.goo.gl/Vx93VH4LxXNCib6m9

For both exhaust valves I couldn't get there at all, no matter how short or long I adjusted the push rod:

https://photos.app.goo.gl/p5DGDKQkyYaeRKzY9

Exhaust valve closed:

https://photos.app.goo.gl/jkZ8EywQMMtviSbi9

Exhaust valve fully open:

https://photos.app.goo.gl/dPxysSHzpzJB56EeA

Now the questions:
Am I missing something?
Is it a problem at all?
Only way I see to rectify this is to bend the rocker arms. Has this been done before?

 

[comnoz]

It looks normal.

Don't bend the rockers.

You have not actually changed the geometry by changing the pushrod length. Only changing the valve stem height will change the geometry more than just the small change you get by moving the adjuster.

IE -if your valve stem height is correct and the adjuster is somewhere besides at the extreme ends of it's range then you are good to go.

 

[Joachim]

Thank you. Glad to hear that. So probably the reason for the difference between inlet and exhaust is because the exhaust valve seat had to be re-cut a fair bit deeper than the inlet.

 

[comnoz]

Thank you. Glad to hear that. So probably the reason for the difference between inlet and exhaust is because the exhaust valve seat had to be re-cut a fair bit deeper than the inlet.

Yes, I am sure that is right. If your stem height is over 1.840" then you probably should have installed seats.

Otherwise watch your spring installed height and shim as needed.

 

[Joachim]

Is stem height the dimension how far the valve sticks out of the head? Its 1.815" (46.1mm) in my case.

Spring installed height is 0.023" (0.6mm) too long compared to values in the manual.

Should be good to go?

 

[comnoz]

Is stem height the dimension how far the valve sticks out of the head? Its 1.815" (46.1mm) in my case.

Spring installed height is 0.023" (0.6mm) too long compared to values in the manual.

Should be good to go?

Yes, that should work.

 

[Joachim]

Thank you very much Mr. Comnoz!