Diamond Forged Piston Kit — Subaru / Toyota FA20 / 4U-GSE BRZ / 86
Diamond Forged Piston Kit — Subaru / Toyota FA20 / 4U-GSE BRZ / 86
Diamond forged pistons for Subaru / Toyota FA20 / 4U-GSE BRZ / 86
Choose a 4-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. The listed pin is already included in the selected kit; this listing does not add a separate pin-upgrade charge.
| Piston Quantity | 4 |
|---|---|
| Compression Height | 1.285 IN |
| Stroke | 86.00 MM |
| Rod Length | 5.090 IN |
| Ring Set Thickness | 1.20 MM x 1.20 MM x 2.00 MM |
| Forging Type | Full Round |
Kit selection
| Kit SKU | Bore | Crown volume | Ratio | Included pin | Ring set | Retainer | Oil-rail supports |
|---|---|---|---|---|---|---|---|
| 36043-4 | 86.00 MM | -14.50 CC | 9.50:1 nominal | G8662250180C | 09573385 | 015113-8 | No |
Fitment and assembly
For first-generation BRZ/86 FA20 / 4U-GSE builds using the listed geometry. Do not use this as a blanket fitment claim for FA20DIT, FA24 or second-generation BRZ/GR86.
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.
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