When and why do I want to do a balance shaft delete?

Almost all engines create harmonics when in motion (read vibration). Some designs are more vibration prone than others and one of these designs is the inline 4 cylinder. Some manufacturers dont spend much time worrying about the vibration because generally its really hard to detect. Others such as Mitsubishi decided that in order to refine the driving experience they would add a counterweighted shaft that spins twice crankshaft speed to counteract that vibration. It works well in stock motors and mildly modified engines alike.

However there are 2 things that contribute to balance shafts eventually causing an engine failure. They are: Extended usage at high rpm (remember the spin twice as fast, so at 8k its spinning 16,000rpm) Bearing failure Now the last problem is directly related to the first. Eventually the balance shaft bearings wear out because of the life the lead and it cause failure in a couple ways. Most notable is when the bearing starts to fail it can flush metal through the motor and take out main and rod bearings, the turbocharger, cams, etc. Next is is it can seize and cause the timing belt to skip and in the worst case version lead to bent valves and a ruined cylinder head.

So what can you do to prevent this?

Obviously at anytime you can have a balance shaft delete kit installed by trained professionals. When is a good time? If you are doing an engine build it is the easiest and least costly. We charge $50 for the kit AND install when doing a full build. The next best time is when having your 60k service done and the timing belt and balance shaft belt off anyway. Our normal service charge for the 60k is $240 for labor, $80 for belts, and the waterpump depends on the model.

1G and 2G DSMs have fairly inexpensive waterpumps (at the time of this article around $65) where the Evo VIII is $185 and the Evo IX is $225 (yikes huh? I have one as well so we're in it together). Now the balance shaft belt is only $20 by itself but for $300 (this is kit, labor, oil and filter) you can get rid of that balance shaft while we are in there.

Who really needs to consider doing this?

Cars with high mileage Anyone who will be racing the car. This is Drag Racers, AutoXers, Road Racers, Rallyists, etc. If you are doing an engine build (protect your investment) Those that want to limit the possibility of engine failure. I think this last one is all of us, I dont know anyone that wants to pay for a new motor if they can choose to do otherwise. While some aspects of this might be debatable, it is generally accepted that other than some increased vibration a balance shaft delete is a must for high performance 4G63s and 4G64s.