cficare68

iTrader: (6)

If you are going to delete the balance shafts there are two ways to it.

1) Use a turned balance shaft. Turned down shaft still provides the support for that oil pump gears like it is designed to do from the factory. But it eliminates the balance shaft in the rear of the motor hence deleting the need for the balance shaft belt.

2) Use a stubby balance shaft delete. The key to keeping your oil pump alive with the stubby balance shaft kits are changing the oil pump gears from the OEM Helical gears to straight cut gears. The problem with the helical gears are with the stubby balance shaft they deflect. Which in time kills the oil pump and causes failure. The straight cut gears prevent the deflection and help keep the oil pump alive. You can buy OEM straight cut gears out of the 90 dsm for about $150 and they work flawlessly.

kikiturbo

option 1 still leaves a plain bearing running at 2x engine speed
Truth be told I really dont see what kind of support the long shaft gives the oil pump..
also, why would the helical gears deflect and straight wouldnt?? The only thing helical gears do produce is axial force that the straight gears dont have... And that force is dealt with by the housing..

cficare68

iTrader: (6)

On a helical gear your pressure is going to start on end and then roll itself across the tooth causing an uneven amount of force in one section of the tooth itself then bounces the force constantly back and forth on the tooth as it rotates. Straight cut gear keeps a constant equal force threw out the entire gear for the entire duration of the gear rotation putting less strain on the part itself.

MIL.SPEC Erik

I will be running the Evo 9 OEM kevlar belt. However, my engine builder said he has witnessed some Evos with the kevlar BS belts experience the belt coming/slipping off, so he recommended the OEM belt.