Diamond Forged Piston Kit — BMW S63B44 4.4L V8
Diamond forged pistons for BMW S63B44 4.4L V8
Choose a 8-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.
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. The listed pin is already included in the selected kit; this listing does not add a separate pin-upgrade charge.
| Piston Quantity | 8 |
|---|---|
| Compression Height | 1.259 IN |
| Stroke | 88.3 MM |
| Forging Type | Full Round |
Kit selection
| Kit SKU | Bore | Crown volume | Ratio | Included pin | Ring set | Retainer | Oil-rail supports |
|---|---|---|---|---|---|---|---|
| 83117-8 | 89 MM | -10.3 CC | Not published | H8662250225C | 09553504 | 015113-16 | Confirm with BBT |
Fitment and assembly
Confirm the exact S63B44 revision and rod specification with BBT before ordering. The supplier does not publish a compression ratio for this kit. Do not assume interchangeability across S63 generations.
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.