Lightening Crank?

**JeepMadness1979** · 28 Jun 10 01:24 pm

I have seen this on pirate they drill their crank shafts with a few holes evenly throughout the lobes. What are everyones idea on doing this? I would be an interesting idea to do to my buggy project.

**Zukman** · 28 Jun 10 07:59 pm

Cuts down on rotating weight, i.e you can hit rpms faster.

**AKMark** · 28 Jun 10 08:29 pm

Weakens crank, personally I would not do this.

**Zukman** · 28 Jun 10 08:41 pm

You can lighten a 6.2 crank by chucking a rod!

**akram** · 28 Jun 10 10:18 pm

I knew several folks who did this on their dirt track cars for the quicker revs. never seen one break or seen one be weakened by it. The biggest issue is getting the holes spaced exactly even and the same size so you don't through it out of balance. I've seen ones out of balance cause issue.

**JeepMadness1979** · 29 Jun 10 07:14 am

I less rotational weight should also decrease the torque out put... right?

**Zukman** · 29 Jun 10 07:44 pm

Yes, In would effect the torque output.

**SamuraiMike** · 02 Jul 10 06:39 pm

Most offroaders with manual tranny try to find the heaviest flywheel they can find, it keeps the rig from stalling out. The only person I trust to drill a crank is the machinist balancing it.... It would be like a 2 stroke dirt bile, as long as the revs are theere, it will go, but it won't lug down at all...