Diamond Forged Piston Kit — Ford Barra XR6 4.0L
Diamond forged pistons for Ford Barra XR6 4.0L
Choose a 6-piston kit to suit your measured engine and planned rotating assembly. The selector identifies the catalogue bore, piston crown volume, nominal compression ratio where published, and supplied gudgeon-pin option.
Photo: representative Diamond piston catalogue image. Crown shape, valve reliefs, skirt finish and supplied components may differ by the selected part number. Use the kit specifications and option selectors to confirm your order.
Made to order and delivery
These pistons are supplied by BBT as special-order, made-to-order items. Allow approximately 5–6 weeks for delivery, pending Australian customs processing time. Supplier manufacturing schedules, international freight and customs clearance can extend the estimate. Contact BBT before ordering for a time-critical build.
Included components and build dimensions
2618 aluminium forged pistons, the listed ring set, gudgeon pins and retainers are included. Part numbers ending in -H select the upgraded H13 pin kit at the displayed additional price. Each option is a complete kit.
| Piston Quantity | 6 |
|---|---|
| Compression Height | 1.215 IN |
| Stroke | 3.910 IN |
| Rod Length | 6.058 IN |
| Ring Set Thickness | 1.00 MM x 1.20 MM x 2.80 MM |
| Forging Type | Full Round |
Kit selection
| Kit SKU | Bore | Crown volume | Ratio | Included pin | Ring set | Retainer | Oil-rail supports |
|---|---|---|---|---|---|---|---|
| 30200-6 | 3.632 IN | -15.00 CC | 8.50:1 nominal | G8662500180C | 09533632 | 015113-12 | No |
| 30203-6-H | 3.632 IN | -9.00 CC | 9.00:1 nominal | H8662500225C | 09533632 | 015113-12 | No |
| 30206-6 | 3.632 IN | -4.00 CC | 9.50:1 nominal | G8662500180C | 09533632 | 015113-12 | No |
| 30201-6 | 3.642 IN | -15.00 CC | 8.50:1 nominal | G8662500180C | 09533642 | 015113-12 | No |
| 30204-6 | 3.642 IN | -9.00 CC | 9.10:1 nominal | G8662500180C | 09533642 | 015113-12 | No |
| 30207-6 | 3.642 IN | -4.00 CC | 9.60:1 nominal | G8662500180C | 09533642 | 015113-12 | No |
| 30205-6 | 3.652 IN | -9.00 CC | 9.10:1 nominal | G8662500180C | 09533652 | 015113-12 | No |
| 30208-6-H | 3.652 IN | -4.00 CC | 9.60:1 nominal | H8662500225C | 09533652 | 015113-12 | No |
Fitment and assembly
For Barra inline-six engine builds. Confirm the measured block, cylinder head and rod small end before ordering.
Catalogue bores are finished cylinder-bore sizes. The finished compression ratio depends on chamber volume, deck clearance and compressed head-gasket thickness. Have your engine builder verify piston-to-wall clearance, ring gaps, pin fit and piston-to-valve clearance using the supplied Diamond instructions before machining or assembly.
BBT workshop support
Built by Boost & Tune can help select a specification for your fuel, boost and intended use. Machining, engine assembly, connecting rods and tuning are purchased separately.