[K2e2vin]

did your pulley come with a damper installed because your can eat the bearings on the crank from un dampened harmonic vibrations in the crank. hence the damper built in on the stock pulley.

any reason why you recommend the stock crank pulley? Ive lost / broken all my OE ones and the shitty replacements I get in the market are horribly constructed and overpriced.
with this one I know exactly what I am running. it is perfectly balanced and after running it for 500+ km I dont feel the engine behaving abnormally. if a lightened flywheel is okay as long as it is balanced properly, what makes the crank pulley a no-no?

found something interesting here: Disadvantages of a Lightened Crank Pulley | eHow.com

The oil-pump is directly driven by the crankshaft; and having a damper makes sense to reduce torsional vibration. On the flywheel end, there shouldn't be much vibration due to load(hence the vibration will move out towards the crank pulley) or will be dampened some by the clutch and the inertia of the flywheel.

In your case, and in the case of many NA D15s, you should be fine with a solid pulley. The stroke and torque output isn't as significant thus there isn't as much torsional vibration. I can't say for the D13 or D14, but most D15s came with a solid pulley from the factory. I'd say you're good to go! :TU:

 

[K2e2vin]

Nice!

The r/s ratio is probably negligible when talking about torsional vibration consideration it's more related to crankshaft rigidity. Maybe the wavelength of the oscillation changes? I honestly haven't looked into that; but the vibration occurs after the power stroke when the crank is trying to return to it's normal shape.

If you see a vtec without the better crank. It means they have put in a 1.5 Crank.

Or it's a VTEC-E engine/crank