The 263-SKA Rotating Assembly Kit is made for Tillotson Blocks Bored to 76mm
The 263cc kit is made of a 76mm hypereutectic piston (same material as the 72mm Tillotson Racing Piston), EC's Pinnacle Forged Connecting Rod, and 58mm Ductile Iron Crankshaft.
For comparison, we should look at the differences in displacement among other small block engines.
- 212 70mm x 55mm = 211.67cc (12.92ci) difference 51.45cc(3.13ci) 25%
- 223/224 70mm x 58mm = 223.21cc(13.62ci) difference 39.91cc(2.43ci) 18%
- 225 72mm x 55mm = 223.93cc(13.67ci) difference 39.19cc(2.38ci) 18%
- 228 72mm x 56mm = 228cc. (13.91ci) difference 35.12cc(2.14ci) 16%
- 236 72mm x 58mm = 236.15cc(14.41ci) difference 26.97cc(1.64ci) 12%
- 254 76mm x 56mm = 254.04cc(15.5ci) difference 9.085cc(0.55ci) 4%
- 263 76mm x 58mm = 263.12cc(16.05ci) difference 51.45cc(3.13ci)
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.
Note: This is a EC Carb part, not an NR Racing Kit!
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.
You will gain compression, which can impact what fuel you run or possibly the camshaft and cylinder head you choose.
22cc Combustion Chamber
w/.045 Head Gasket & Zero Deck - 10.67:1
w/.035 Head Gasket & Zero Deck - 11.1:1
20cc Combustion Chamber
w/.045 Head Gasket & Zero Deck - 11.42:1
w/.035 Head Gasket & Zero Deck - 11.92:1
18cc Combustion Chamber
w/.045 Head Gasket & Zero Deck - 12.31:1
w/.035 Head Gasket & Zero Deck - 12.9:1
16cc Combustion Chamber
w/.045 Head Gasket & Zero Deck - 13.35:1
w/.035 Head Gasket & Zero Deck - 14.06:1
14cc Combustion Chamber
w/.045 Head Gasket & Zero Deck - 14.73:1
w/.035 Head Gasket & Zero Deck - 15.61