fortysixandtwo

Different type of harmonic. The type that is typically mounted on the crankshaft snout (outer ring separated from hub, by elastomer layer) , are tuned for a specific range. The stuff put out by companies like Fluidamper are suppose to cover all ranges. But in the end, balance shafts and crank mounted harmonic balancers are suppressing different sources of vibration.

reno808

Roger that

eman930

So what kinda stuff can second order harmonics damage?? I'm just wondering because I've always been eyeing those balance shaft delete kits but always have been kinda scared to give it a shot and have to deal with broken parts

Chris White

My personal opinion is that deleting the balance shafts creates more problems than it solves. I would not build a balance shaft delete engine for street use. The only reason that I would delete the balance shafts is a high RPM track only engine.
Keep in mind that the balance shafts spin at twice the speed of the crank – so if you are building a 8k rpm engine the balance shafts will spin at 16k RPM….that starts to get pretty fast!

Basic info –
Balance shafts are used to create an equal but opposite force created by the vibrations caused by the imbalance inherent to an inline 4 cylinder engine (nothing to do with static balance)

Harmonic Balancer is used to dampen torsional vibrations in the crank shaft. Each power stroke will actually twist individual throw on the crankshaft. When this is done repeatedly the crank shaft may flex more due to resonances of the crank. Flexing steel repeatedly will eventually cause fatigue and failure.

eman930

I totally need to get a second engine, Then I can slowly put together a nice 2.8/3.0 turbo engine with some nice add on stuff

333pg333

Chris, would you always consider deleting the balance shafts for a track car or only those with very high rpms which is very rare on even the highest 944 turbo builds?

blade7

That's my plan.