JE LS1 Extreme Duty Asymmetrical FSR Flat Top Forged Piston (J321242) — Fast Lane Spares Skip to content
💸 BLACK FRIDAY SALE LIVE | LINK, HALTECH, PULSAR + MORE | UP TO 40% OFF STOREWIDE!
💸 BLACK FRIDAY SALE LIVE | LINK, HALTECH, PULSAR + MORE | UP TO 40% OFF STOREWIDE!

JE LS1 Extreme Duty Asymmetrical FSR Flat Top Forged Piston (J321242)

3.905" bore, 3.622" stroke, 6.125" rod length, -20.2cc dome volume
SKU: J321242
Original price $1,826.00 - Original price $1,826.00
Original price
$1,826.00
$1,826.00 - $1,826.00
Current price $1,826.00
+ GST
Availability:
Low stock, please contact before purchasing

J321242 - LS1 3.905" PISTONS -20cc DISH

3.905" bore, 3.622" stroke, 6.125" rod length, -20.2cc dome volume

Part Number: J321242

We have redesigned and expanded our GM LS1 series product lines! These new pistons utilized our dedicated Forged Side Relief (FSR) forging that was specifically designed for high output GM LS1 series engines. In addition we have found ways to reduce weight and maintain the durability needed for both street and racing use. Lightweight and extremely durable, these pistons are machined for 1.5mm, 1.5mm, 3.0mm rings. Wrist pin upgrade recommended above 800hp.
Includes:
Pin #927-2250-15-51C (106g)
Round Wire Locks # 927-073-MW

Features:

High strength FSR forging
Accumulator Grooves
Double Pin Oilers
Offset Wrist Pin
Piston Specifications

Make: CHEVROLET
Engine: CHEVROLET LS GEN III/IV
Bore Diameter: 3.905
Compression Height: 1.315

Compression Ratio with 64cc chamber volume: 8.7

Compression Ratio with 66cc chamber volume: 8.5

Compression Ratio with 72cc chamber volume: 8.0

Piston Volume: -20.2

Cylinder Head: LSX/L92 12 DEG
Piston Pin Outside Diameter: 0.927

Piston Pin Length: 2.250
Piston Pin Material: 5115
Ringset Included: No
Top Compression Ring Thickness: 0.06
Second Compression Ring Thickness: 0.06
Oil Ring Thickness: 0.1175
Piston Material: 2618
Forging Type: FSR
Piston Avg Weight: 421

Pin Wall Thickness: 0.170
Piston Type: Dish