Forged Pistons for Subaru, EJ257 WRX STI (stroker), 99.75mm, 8.5:1 (CP Pistons SC7434)
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|
Make |
Subaru |
|
Model |
EJ257 WRX STI (stroker) |
|
Part Number |
SC7434 |
|
Cylinders |
4 |
|
Bore (in) |
3.927 |
|
Bore (mm) |
99.75 |
|
Size |
+0.25mm |
|
Stroke |
83 |
|
Conrod |
130.5 |
|
Comp Height (in) |
1.123 |
|
Comp Height (mm) |
28.5 |
|
Dom/Dish CC |
|
|
Compression Ratio |
8.5 |
|
Weight (Grams) |
396 |
|
Pin (mm) |
23 |
|
Rings |
RS1658-3927-0 |
|
Ring Thickness |
1.2 x 1.2 x 2.0mm |
|
Pin included (Standard) |
905-2500-18CP1S |
|
Upgraded Pin |
905-2500-20CP3S |
|
Ultra Duty Pin |
905-2500-26CP3S |
|
Locks |
905x055 SUB |
CP pistons are compatible with oversized valves and high lift camshafts. CP Pistons represent the highest quality and is engineered for maximum power. Standard features include: Deep valve reliefs accommodate high lift camshafts; Larger valve reliefs for +1mm valve sizes; Custom skirt cam and barrel design; Accumulator grooves; High strength aluminum forgings; High performance rings; Fully CNC machined and balanced to +/- 1 gram; Wrist pins included at no additional cost; Double pin oilers force fed from oil ring groove; Pin lock grooves for easy lock removal; Pin fitting included.
| Product Name | Forged Pistons for Subaru, EJ257 WRX STI (stroker), 99.75mm, 8.5:1 (CP Pistons SC7434) |
|---|---|
| Brands | CP Carrillo |
| Engine | EVO VIII / EVO IX |
| Make | Subaru |
Delivery & Freight
We are an Australian-based company that ships items nationally and internationally, usually within 48 hours of receiving your order. High-value items shipped internationally are sent via DHL Express, while lower-value items are sent via Australia Post Express unless otherwise instructed.
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Disclaimer:
Product images are for description purposes only. Actual product may vary.
Shipping calculations available at checkout.
If you are unsure, get in touch by emailing [email protected], messaging us on Facebook, or phoning us at +61 7 5645 1333 (8am to 2pm AET).
What information do I need to match these pistons to my engine?
You need the engine code, bore size, stroke, rod length, pin diameter and target compression ratio. These determine the correct piston compression height and crown design.
How should ring gaps be set for these pistons?
Ring gaps must be set by your engine builder based on fuel type, boost level and the intended rpm range. Forced-induction engines usually require larger gaps.
Are forged pistons suitable for street engines?
Yes. Forged pistons handle detonation and high cylinder pressure better than cast units. Your builder should set the piston-to-bore clearance to suit your application.
What is the recommended bore clearance for the SC7434 pistons?
For the SC7434 pistons, a typical bore clearance of 0.0015" to 0.0025" is recommended. However, this can vary based on the specific application and the engine builder's preferences. Always consult with your engine builder for the best fitment.
What type of rings are included with the SC7434 pistons?
The SC7434 pistons come with high-performance rings, specifically the RS1658-3927-0 set. These rings are designed to provide optimal sealing and durability under high-performance conditions.
Can the SC7434 pistons accommodate oversized valves?
Yes, the SC7434 pistons feature deep valve reliefs that can accommodate oversized valves and high lift camshafts, making them suitable for performance builds that require enhanced airflow.
What is the weight of the SC7434 pistons?
Each SC7434 piston weighs approximately 396 grams. This lightweight design helps reduce reciprocating mass, which can improve engine response and performance.
What is the compression ratio of the SC7434 pistons?
The SC7434 pistons have a compression ratio of 8.5:1. This ratio is suitable for applications that require a balance between performance and reliability, especially in turbocharged setups.
