The new motor sports a bigger bore(3.75 inches as compared to the EVO's 3.5). Centrifugally cast liners are used.The cylinders have a O-ring seal.At the Twin Cams bottom end ,a straight crankpin is utilized. There is a larger diameter crankpin.Engine stroke has been reduced to 4 inches, providing quicker revving,crisper throttle response and smoother power with less vibration.The engine has 12 mm spark plugs, giving more room on the sides of the head's combustion surface.The combustion chamber has been configured into a bathtub- style shape,generating an improved flow of gasses,and more power.Compression ratio has been upped to 8.9:1  

One of the greatest changes revealed inside the motor is its all-new two-cam sub-assembly.The twin camshafts are carried on both sides by bearings.Mechanical noise has been reduced by means of chain drive instead of a gear mesh.

Overall,there is 50% more cooling fin area to the new Twin Cam 88.

The new Twin Cam oilpump is integreted in the engine.The cranckcase has a attached oil filter setup, which houses a 10 micron spin-on filter.