The 263R Rotating Assembly is made for the Tillotson R-Series Blocks bored to 76mm.

The new 76mm hypereutectic piston(same material as the 72mm Tillotson Racing Piston) is an affordable option for those who want a 3-inch bored engine.

The 76mm piston is very lightweight, which can help with the “balance” of the rotating assembly, improved acceleration, and increased durability. The piston journal’s improved strength is that it is wider than the Tillotson 72mm piston and uses a longer 13mm wrist pin. 

The compression height(.715 vs .765) is now shorter to allow longer rods. Use our new 8282 billet rod with our 58mm crankshafts to make a 263cc engine. 

We measure the weight of common stock pistons assemblies (piston, rings, wrist pin, and clips) and a couple of market pistons of similar sizes to see how they compare to the 76mm piston assembly. The 76mm piston assembly weighs 195g.

68mm Clone Dish Piston(Lightweight)  – 207g 

70mm Predator Hemi Flat Top Piston   – 203g

72mm Tillotson Racing Piston               – 172g

2.8335 Wiseco Single Ring Piston        – 192g

2.985 Wiseco Single Ring Piston          – 208g

The New 76mm piston is 8mm larger than the 68mm piston and 6mm more than the typical flat top 212/223/224 piston that comes in the 196cc clone, but the 76mm assembly weighs 10-12g less. The 2.8335 Wiseco is 4mm smaller and only weighs 3g less, and the nearly equal-sized 2.985 piston weighs 13g more. 

The best of all the features is the price. Compared to many, aftermarket pistons cost nearly twice as much. 

The Piston Assembly includes:

– 76mm Hypereutectic Piston

– Standard Rings

– 13mm “Long” Wrist Pin

– Circlips