WHY YOUR ENGINE NEEDS A GOOD CRANK DAMPER
Forget what you have heard or read about lightweight crank hubs. They may have a lower moment of inertia, but do not deliver more power than a heavier crank damper. In the real world, it's not as simple as the dynamics of a crankshaft. At some point in the mid- to upper-rpm range, the damper will go into a bending and torsional vibrational resonance. In so doing, it will behave something like this.
This results in adverse modifications...
This results in adverse modifications to the intended valvetrain motion such as seen here. This can cost up to 14 hp on a 500hp V-8. The fix is an effective damper.
Curve 1 is a solid hub. Curve...
Curve 1 is a solid hub. Curve 2 is a damper that's too small for the job. Curve 3 is a larger damper that is getting the job done.
10 Rules For Successful Stroker Builds
1. Select as long a rod as possible to minimize frictional losses from side loading and cut the engine's mechanical noise.
2. Select the lightest reciprocating components for the bottom end.
3. Use an effective crank damper.
4. Use an oil pan that keeps the oil away from the bottom end rotating assembly as entrainment will cost big power and may lead to failure.
5. Go for as high a compression ratio as possible as it will offset the engine's reduced mechanical efficiency due to its greater piston friction.6. Use cylinder heads with valves as large as possible as there are a lot more cubes to feed.
7. Be sure to tighten up the cam's Lobe Centerline Angle (LCA) from whatever was optimum before by about 1 degree for every 16 cubic inches of capacity increase.
8. Increase valve lift by at least the same proportion as the increase in displacement.
9. Make sure the induction system has enough flow capability to handle the extra inches.
10. Try to keep the induction system cool as this makes more difference with a stretched engine.