Mahle SBC425040F05
The Mahle PowerPak piston is a forged item that features a phosphate dry-lubricant coating, which protects the piston against ring microwelding and wrist-pin galling that otherwise may occur during start-up or break-in. The piston skirts are additionally protected with a unique Grafal antifriction coating. Each 4032 high-silicone, low-expansion piston forging is hand deburred, and each valve pocket is radiused.
| Bore | 4.040 inches |
| Stroke | 3.750 inches |
| Rod length | 5.70 inches |
| Compression height | 1.425 inches |
| Compression | 11.3:1 (approx) |
| Style | Flat-top |
| Head volume | 64 cc |
| Material | Forged, high-silicone |
| | low-expansion aluminum alloy |
| Pin diameter | 0.927 inch |
| Pin type | Floating |
| Top groove | 1.5 mm |
| Second groove | 1.5 mm |
| Oil groove | 3.0 mm |
| Weight | 456 g |
| Dome volume | -5 cc |
| Price | $597 |
Manley 590730
Manley's Platinum piston is manufactured from 2618 alloy for excellent high-temperature strength and fatigue resistance. Pressure-balance grooves between the rings promote better ring sealing. All final machining to the piston is performed on the same fixture so that the rings match the cylinder walls with total squareness. The wrist pin is manufactured from tool steel. The piston skirts feature a full-band design for improved skirt stability.
| Bore | 4.030 inches |
| Stroke | 3.750 inches |
| Rod length | 5.70 inches |
| Compression height | 1.425 inches |
| Compression | 11.1:1 (approx) |
| Style | Flat-top |
| Material | 2618 forged aluminum |
| Head | 64 cc |
| Pin diameter | 0.927 inch |
| Pin type | Floating |
| Top groove | 11/416 inch |
| Second groove | 11/416 inch |
| Oil groove | 31/416 inch |
| Weight | 438 g |
| Dome volume | -4 cc |
| Price | $520 |