rotary valve timing

[brucep1bruce]

Every video shows after using the degree wheel and they all wind up putting the rotary valve so its at the bottom edge of the intake port at tdc mag side. Unless I'm missing something why cant you just put the mag side at tdc and install the rotary valve so its at the bottom edge of the intake port and not use the degree wheel?

 

[mikidymac]

Then every video you have watched they are doing it wrong. With the MAG piston at TDC the bottom edge of the rotary valve should not be aligned with the intake port.

The bottom edge of the rotary valve should be 64 degrees below the top of the intake port on a 787 engine.

 

[brucep1bruce]

YOUR RIGHT THANKYOU

 

[brucep1bruce]

WOULD THIS CAUSE IT TO BACK FIRE OUT THE CARBS IF ITS WRONG AT WOT

 

[mikidymac]

I would sure think so if the timing is off.

 

[brucep1bruce]

So can l use the degree wheel and set the rotary valve at 64 degrees below the top of the intake to set the timing?

 

[Cheflen]

So can l use the degree wheel and set the rotary valve at 64 degrees below the top of the intake to set the timing?

Let me know how this works, I just set my rotary valve at the bottom of the intake on my 580 and it worked fine and now I need to time my 717 and I need to figure out how to properly do it