J.E. PISTONS 138979 Rings Piston 12.0 945 1.00

( Brand: J.e. Pistons ), ( Manufacturer Part Number: 138979 ), ( Part Type: Ring Piston ), ( Disclaimer: Picture For Illustration Purposes Only. Actual Product May Vary ), ( Manufacturer Warranty: No Warranty ), ( Option: 72 Mm 12.0 )

Review J.E. PISTONS 12.0 945 1.00 fits 1972

JE Pistons part number 138979 is a high-performance piston designed for applications where increased power and durability are required. This piston is specifically engineered for use in a 72mm bore, 12.0:1 compression ratio, naturally aspirated engine with a displacement of 945 cubic centimeters and a bore stroke ratio of 1.00.

The piston crown is constructed from JE's proprietary 2618-T431 alloy, which provides excellent strength and thermal properties. The crown design features a dish shape to provide optimal combustion chamber volume and shape for efficient combustion. The crown also includes a ring groove for the installation of compression rings.

The piston skirt is designed to provide a snug fit within the cylinder bore, minimizing the potential for piston slap and reducing engine friction. The skirt is made from JE's 4032 alloy, which offers excellent wear resistance and strength.

The piston pin bore is machined to precise tolerances, ensuring a secure fit of the piston pin and minimizing the potential for piston-to-crankshaft contact. The piston pin itself is made from high-strength material to provide reliable support for the piston during engine operation.

The piston also includes a base gasket ring, which helps to seal the piston within the cylinder bore and prevent the loss of compression. The piston rings, which are not included with this part number, must be selected based on the specific engine application and fuel type.

In summary, JE Pistons part number 138979 is a high-performance piston designed for use in a 945cc, 12.0:1 compression ratio, naturally aspirated engine with a 72mm bore and a bore stroke ratio of 1.00. Its features include a strong and durable piston crown, a snug-fitting piston skirt, and precise machining for a secure fit within the engine.

Product: J.E. Pistons Part Number: 138979, 72mm Bore, 12.0:1 Compression Ratio, 945cc Displacement, 1.000" Dome Height

1. High-performance piston designed for racing and high-horsepower applications.

2. Manufactured using J.E. Pistons' proprietary process, ensuring superior strength and durability.

3. Designed to provide increased power and torque, resulting in improved engine performance.

4. Widely used in various racing series and applications, ensuring availability of supporting parts and expertise.

1. This piston is specifically designed for racing and high-performance applications. Therefore, it may not be suitable for daily-driven street vehicles due to its aggressive design and potential for increased engine wear and noise.

2. The piston's high compression ratio may require the use of premium fuel to achieve optimal engine performance.

3. Installation of this piston may involve additional costs for engine machining and assembly services.

The J.E. Pistons Part Number 138979 is a high-performance piston designed for racing and high-horsepower applications. While it offers numerous advantages such as increased power, durability, and improved engine performance, it may not be suitable for daily-driven street vehicles due to its aggressive design and potential for increased engine wear and noise. Additionally, the use of premium fuel and additional installation costs are important considerations. Ultimately, the decision to purchase this piston depends on the specific application and performance goals.

If you are building a high-performance racing engine or a street engine intended for regular track use, the J.E. Pistons Part Number 138979 could be an excellent choice due to its proven performance and durability. However, if you are looking for a piston for a daily-driven street vehicle, it may be more prudent to consider a lower-performance, stock replacement piston. Ultimately, it is recommended that you consult with a professional engine builder or mechanic to determine the best piston for your specific application.

Details:

Machined from 2618-T6 high tensile forged aluminum. Made in the USA. Dome/dish features smooth flowing radii; require no debarring or preparation. Pistons Products:: From Dayton to Bonneville, JE continues set the standards in street bike piston design.

No junk, no knock offs and seconds. JE has recorded wins at Dayton with American Honda's CBR600RR, low Eats on the drag strip and land speed records Bonneville. Pins, pin fitment, lock and rings included.

part #: 138979 prices

• $845.99-$939.99

specifications pistondon:

• for years: 1972
• brand: J.e. Pistons
• mpn: 138979
• part type: Ring Piston
• disclaimer: Picture For Illustration Purposes Only. Actual Product May Vary
• manufacturer warranty: No Warranty
• option: 72 Mm 12.0

offer pistondon:

• options: Ship-to-home
• availability: In Stock
• started: August 16, 2025
• quantity: 4
• sold: 0

shipping pistondon:

• type: Fixed
• cost: $0.00
• transit: 6-6 Days
• class: Standard, Expedited
• service: Standard, Expedited

general pistondon:

• Motorcycle Scooter Parts Accessories > Engines Engine Parts > Pistons, Rings Piston Kits
• condition: New

payments pistondon:

• other
• wallet: Google-pay
• credit card: Visa

returns pistondon:

• policy: Returns Accepted
• time: 30 Days
• paid by: Seller

seller pistondon:

• city: Springfield, Missouri
• rating: 99.8%
• # reviews: 64568

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