montanacivic

Hey guys so today, I lost my crank pulley, last owner must have not tighten the bolt when installing the new motor.. now from what I have read a light weight crank pulley is not good on the D16y7, could any 1 point me in the right direction to get the right 1 I need?? From what I see a factory 1 is close to $100 but a aftermarket 1 runs from $50-300

ezone

Stock, used, junkyard?

mikey1

how long was the engine running after it fell off?

you can do alot of damage to your crank and bearings running the engine without that pulley on

EdGasket

Why is that then? Surely the pulley is just a load on the end of the crank but insignificant compared to the flywheel? Genuinely interested why damage might occur without it?

mikey1

it is balancing the crank, its not just a pulley, its a balancer

if that balancer is missing with the engine running it can damage the crank bearings

ezone

Because it's a torsional vibration damper, but that's not all that important right now.


A pulley that has been allowed to run loose can and will tear up the metal on the mounting surfaces of the crankshaft and pulley (a replacement may not fit tightly around the shaft, causing excessive runout and thus even more vibration), and can and will allow the unsecured crankshaft timing gear to do the same (if it does not move and allow the timing belt to be ruined or jump time), along with beating the crap out of the keyway areas so nothing correctly aligns with true TDC anymore.

This usually happens long before hurting anything else inside the engine, as this is the usual immediate damage.

EdGasket

Thanks, I didn't know that.

EdGasket

I've been thinking about this and I appreciate what a harmonic balancer (i.e. fancy crank pulley with rubber layers to dampen vibration) does but that doesn't explain how older engines that only had a simple solid metal pulley driving just an alternator, worked fine? Also why would lightweight and underdrive pulleys be available as these would negate the balancer function?

ezone

Is your crankshaft damaged from the pulley coming loose?
Timing gear?
Keyways?