Pics needed: Trigger Wheel Setup

[TimZ]

With all due respect, yes, you do need a damper, unless you are planning to tear-down the bottom end of the motor after every few runs/outings (depending on how hard you are hitting it - ask Jeff Priddy) and have the budget to replace parts fairly regularly.

 

Even on normally-aspirated inline four-cylinder engines, we have seen crankshaft journal flexing of two degrees or more with no harmonic damper installed, in our dyno/torsiograph tests. In serious performance applications, you can expect that much flex to shear cranks at the flywheel after a few laps in a road race environment. Inline-six cranks are notoriously worse (ask the BMW racers what they have been going through.)

 

Anyone who wants to read-up on exactly what harmonic dampers actually do can click the link below for a technical document which our head of damper development wrote:

 

Click Here (230K PDF)

 

Cheers,

Chris @ BHJ

 

Thanks Chris - that is a really good paper.

 

Mods - could we move this to another forum where more people will see it and make it a sticky?

 

Maybe this could cut down on the "you don't need a 'balancer' if your crank is internally balanced" discussions.

[RTz]

Mods - could we move this to another forum where more people will see it and make it a sticky?

 

 

http://forums.hybridz.org/showthread.php?p=1031208#post1031208

[chris @ bhj]

yes but they also offer stock pulley modification w/ a trigger wheel instead of the aftermarket aluminum one...

 

That would be a preferable alternative to the pulley-only approach if you care about longevity. When properly done that may be a more affordable way to go, as long as the operational parameters of the engine are not pushed too far from stock (redline, long durations at high rpm, etc.) Keep in mind that stock harmonic dampers are designed for stock usage.

 

Cheers,

Chris @ BHJ