Key specs
- Bore Diameter
- 99.50 mm
- Compression Height
- 30.70 mm
- Engine Detail
- Subaru EJ257
- Forging Type
- FLAT
- Oil Ring Thickness
- 2 mm
- Piston Material
- 2618
Have it fitted at Willys
We fit parts at our Oxley and Warana workshops. Order the part and we'll book you in, or ask for a fitted price first.
Get a fitting quote- Returns within 30 days
- 12 month warranty
- Fitting available
Wiseco Engine Internals Performance Pistons Subaru EJ Forged Pistons
Wiseco Professional Subaru EJ257 Piston Set of 4 - 99.50 mm Bore - 30.70 mm CH, -19.00 CC
- Fits Subaru
- Fits STI GD
- Fits STI GR / GV
- Fits STI VA STI
- Fits EJ257
$1,428.92
Including GST
Available to order – usually ships in 2-3 weeks
or 4 interest-free payments of $357.23 with Afterpay on orders up to $2,000Zip and humm are available over the phone: (07) 5619 7869
Will it fit your vehicle?
| Make | Model | Series | Years | Engine |
|---|---|---|---|---|
| Subaru | — | — | — | — |
| — | — | — | — | EJ257 |
| Subaru | STI | GD (Impreza WRX STi) | Aug 2005 – 2007 | EJ257 |
| Subaru | STI | GR / GV (Impreza WRX STI) | Feb 2008 – 2014 | EJ257 |
| Subaru | STI | VA STI (2014-2021) | Apr 2014 – 2021 | EJ257 |
A dash means the listing does not narrow it down that far (for example no build dates are listed). Check with us if your vehicle was built near a model change.
Fitment listings are a guide. Not sure? Send us your rego or VIN and our team will check the part for your vehicle, before or after you order.
Check my fitmentor call(07) 5619 7869or text0485 885 957oremail us
Bore 99.50 mm · Compression height 30.70 mm · Volume -19.00 cc · Set of 4 · rings included · wrist pins included
Description
Set of 4 Wiseco Professional Series forged pistons for the Subaru EJ257: 99.50 mm (3.917 in) bore, 30.70 mm (1.209 in) compression height and -19.00 cc crown volume. Rings and wrist pins are included.
What’s in the box
- 4 forged pistons
- 4 wrist pins (23.00 mm / 0.905 in diameter, 9310 steel, floating)
- Piston ring set
Matching it to your Subaru EJ257
Crown volume is quoted as -19.00 cc: Wiseco use a negative figure when the dish or valve reliefs add volume to the combustion chamber. Work out the compression ratio for your combination (chamber volume, gasket bore and thickness, deck clearance) before you order.
The bore size is the finished bore these pistons are made for, so have the block measured and then bored and honed to suit, with piston-to-wall clearance set to Wiseco’s figure for part K598M995.
Material: 2618 aluminium, the low-silicon alloy usually chosen for boosted and high-load engines (it needs more piston-to-wall clearance than 4032).
Ring grooves: 1.2 mm top, 1.5 mm second and 2 mm oil.
Boostline conrods listed for this engine family: Boostline Connecting Rod Kit | EJ20/25 Turbo 130.5 | ARP2000, Boostline Connecting Rod Kit | EJ20/25 Turbo 130.5 | ARP625+. Match the rod length to the pistons before you order.
More: Subaru EJ forged pistons · all performance pistons · Wiseco
Wiseco part number: K598M995
Specifications
| Bore Diameter | 99.50 mm |
|---|---|
| Compression Height | 30.70 mm |
| Engine Detail | Subaru EJ257 |
| Forging Type | FLAT |
| Oil Ring Thickness | 2 mm |
| Piston Material | 2618 |
| Piston Quantity | 4 |
| Piston Volume | -19.00 cc |
| Ring Set Included | Yes |
| Second Compression Ring Thickness | 1.5 mm |
| Skirt Coating | Yes |
| Top Compression Ring Thickness | 1.2 mm |
| Wrist Pin Included | Yes |
| Wrist Pin Material | 9310 |
| Wrist Pin Outer Diameter | 0.9055 in |
| Wrist Pin Style | Floating |
| Brand | Wiseco |
| SKU | WPC-K598M995 |
| MPN | K598M995 |
Warranty: 12 months from Willys Workshop
Sold and warranted by Willys Workshop. Parts carry our 12-month warranty against defects, from the date of purchase or installation (whichever is later), subject to any manufacturer terms and fair wear and tear (Terms & Conditions, clause 7.1(b)). This is in addition to your rights under the Australian Consumer Law, which cannot be excluded.
- 30-day change-of-mind returns on eligible items: unused, uninstalled and in the original packaging, with a Return Authorisation from us first. A 15% restocking fee applies and return postage is at your cost.
- Wrong fit: if a part covered by our Fitment Guarantee doesn’t fit, we pay the return freight both ways and there’s no restocking fee.
- Special-order or imported-to-order items, electrical parts, ECUs and tuners once registered, connected or flashed, parts that have been fitted or modified, and clearance items can’t be returned for change of mind. Your rights for faulty goods still apply.
- Refunds are made to your original payment method within 14 business days of us receiving and inspecting the return.
Full details: Returns & Refund Policy and Terms & Conditions.
Warranty claims are coordinated through Willys Workshop. Email sales@willysworkshop.com.au or call Warana (07) 5619 7869 / Oxley (07) 3377 3421 with your order number and a description of the issue.
Shipped Australia-Wide
- Dispatched from within Australia with tracking.
- Available to order – usually ships in 2–3 weeks.
- Freight is quoted after you order – we confirm the cost to your address before dispatch.
- Delivery usually takes 2–10 business days after dispatch, depending on your location.
- Need your tracking number? Once your order has shipped, email sales@willysworkshop.com.au with your order number and we’ll send you the carrier and tracking details.
Freight question? Call us on (07) 5619 7869.
