Rotary Valve Timing

[CheeseBurger]

:( Got a 96 Challenger with 787 motor with valve PN: 290 924 508 (159 Degree Cutout).

The maintenance manual doesn't address settings for the Challenger as it does the XP's, GSX's, etc.

Anyone have experience on this (opening & closing degree angles)?

[Bryan Glynn]

It's the same as all the other 720 and 800's. 147.

[John Kubiak]

Actually, you shold be more concerned with the close timing, which is 65 degrees. The reason for this difference is the valve is assymetrical, and the timing can vary outside of the close specifications when timed to the opening value

[CheeseBurger]

[img]tongue.gif[/img] Okay, so if I use the same settings as the GSX-GTX (opening 146-147) and (closing 59-69) I will be in the ball park?

But I will be more concerned with the closing setting of 65.

Thanks!

[John Kubiak]

correct

[Paul Zxi n XP]

john, i have an xp 650, with a 650x motor. I understand i have a 158 degree cutout. How do i set it?

what gains will i get if i install a 147 degree valve.

i set up the ski 44mm buckshot carbs, factory pipe with ECWI, 170 compression, 78.5 wiseco pistons.

thanks

[Bryan Glynn]

The 650x is setup the same as the above examples. Using a smaller valve will hurt your performance.