What can I realistically expect from installing one of the lighter crankshaft pulleys on my MCS? Thanks...

 

I'll let you know Tuesday.


Dave

 

expect to damage your engine from un-damped torsional and and lateral vibrations inherent to the inline 4. try the search function.

 

Not sure if this applies but something to consider.

http://dinancars.com/whitepapersFile.asp?ID=5

 

If you are seeking a quicker-revving engine, you'd gain more of a benefit from using a lightened flywheel first. Use the pulley as a last resort, and not on a car that will be seeing primarily street usage. The stock damper incorporates a system which prevents torsional vibrations from affecting the supercharger and other accessories.

Also, if the light crank pulley is any smaller in diameter, you will lose boost and subsequently power as you'll be turning the supercharger slower instead of it's current speed or faster.

My latest 'worry' regarding this mod is a result of seeing threads pop up regarding belt tensioner failures. Adding the solid pulley will markedly increase the torsional vibrations transmitted to the belt and the 'whipping' effect the tensioner already encounters. Just a thought.

 

the Dinan ref is spot on

 

Many thanks for the comments and the Dinan reference :smile: . You've helped me to change my plan to leave-well-enough-alone! Since I already have a 15 lb. flywheel, it seems that the lighter crank pulley could be courting disaster . BTW, jlm, I did try the search function before posting, but was unable to find any threads on NAM. Perhaps I did it wrong...

 

I thought there were a couple of posts a few weeks ago about the lightweight pulley; so:


I just searched on "harmonic" and found a few:

https://www.northamericanmotoring.co...light=harmonic

https://www.northamericanmotoring.co...light=harmonic

https://www.northamericanmotoring.co...light=harmonic

https://www.northamericanmotoring.co...light=harmonic

 

The above link isn't working anymore, try this;

http://www.dinancars.com/bmw/technia...armonic-damper

 

There is no conclusive evidence that lightened crank pulley's cause oil pump failure or any other engine damage!

There are so many sold worldwide to a lot of mini owners, and if there were issues I am sure there would be more cases of blown up engines around the world.

There are also alot of people with crank pulleys that have done a lot of miles and had no issues!!!! https://www.northamericanmotoring.co...=54503&page=10

I think it is a very simplistic approach to blame mechanical failures on non-dampened crank pulleys.

Bottom line is it is up to people to make informed judgements on what they may or may not put on their car!

I will now put my flame suit on, sit in the corner and wait for a roasting...

 

I thought the only aftermarket crank pulleys available were either stock size (0%) or larger?