This engine supposedly made 1000 hp, yet only had 150 cyl psi. Don't see how that's possible. Must be a happy dyno. Not sure on the cam specs, they wont send me or didn't keep cam card.

Hey, you could give it to me! I'll even pay postage.

From my point of view, the rubbed off paint marks show that the damper was doing exactly what it was supposed to. As the power stroke pushes the hub ahead, the inertia ring stays behind, tethered by the rubber that's between the two. Then the rubber unstretches and the inertia ring is back to the starting point, when another power stroke happens and the same things occur again.

The rubbed off paint shows you how much the inertia ring actually moves. I'm surprised at how much it is, but I've never had a damper on a 1000? hp engine either.



R.

Some damper designs are more tolerant of internal engine mods, in which changes to stroke are probably safer.
If you're not sure, read up.
The "harmonic orders" that cause the problems are not a function of balance, or power, or reciprocating weight. They are far more closely related to:
1. crankshaft length
2. stroke length
3. main journal size
4. rod journal size
5. number of mains

Increases to 1. & 2. reduce overall crankshaft stiffness and reduce the RPM at which harmful orders occur (from which the engine needs protection). Increases to 3., 4., & 5. increase stiffness and increase the critical RPM.

Bottom line: don't use a damper designed for an engine with different crank geometry unless you're sure its design accepts the differences.
A stock 383 has very different crank stiffness from a 4.15" stroker with BBC rods.