CP's Bullet Race Series pistons are forged from 2618 aluminum, the ductile alloy CP specifies for severe duty nitrous, blower and turbo builds. This set is machined to a 4.125 in standard bore and matched to a 4.100 in stroke on a 6.200 in rod, a 1.250 in compression height that works out to 438 cubic inches in a small block Ford. The crown is flat top with a single valve relief cut 0.280 in deep on the intake side, a net crown volume of -8.73cc that returns 11.9:1 compression against 62cc cylinder heads. Each piston weighs 438 grams and is balanced to within 1 gram, with dual forced pin oilers, contact reduction grooves, accumulator grooves and forged side relief. Chromoly wrist pins, wire locks and a 1.5mm / 1.5mm / 3.0mm steel ring set are supplied with the set.
| Type | Forged flat top piston set (CP Bullet Race Series) |
| Application | Small Block Ford, 438 cubic inch |
| Material | 2618 forged aluminum alloy |
| Size | STD (standard 4.125 in bore, no oversize) |
| Bore | 4.125 in |
| Stroke | 4.100 in |
| Rod Length | 6.200 in |
| Compression Height | 1.250 in |
| Crown | Flat top, -8.73cc net (valve relief volume, not a dome or dish) |
| Valve Reliefs | 1, 0.280 in intake |
| Cylinder Head Chamber | 62cc (basis for the quoted compression ratio) |
| Compression Ratio | 11.9:1 with 62cc heads |
| Wrist Pin | 0.927 in diameter x 2.500 in chromoly, included |
| Ring Pack | 1.5mm / 1.5mm / 3.0mm steel ring set, included |
| Piston Weight | 438 g, balanced to within 1 gram |
| Gas Ports | No |
| Included | 8 pistons, wrist pins, wire lock retention rings, ring set |
| Quantity | 8 (set of 8 pistons) |
| Part Number | BF6155-STD |
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