DRAG SPECIALTIES 139666 Piston Set Compression 3-7/16 .050 8.5

( Brand: Drag Specialties ), ( Manufacturer Part Number: 139666 ), ( Part Type: Piston Compression ), ( Warranty Details: See Manufacturer )

Review DRAG SPECIALTIES Piston Set 3-7/16 Inch .050 Bore 8.5 Compression Ratio Harley Davidson fits DS

Introducing the 139666 DS Piston Set from Harley-Davidson, specifically designed for engines with a piston bore size of 3-7/16 inches and a compression ratio of 8.5:1. This piston set is an essential upgrade for Harley-Davidson motorcycles seeking improved performance and reliability.

Each piston is meticulously crafted from forged aluminum alloy, enhancing their strength and durability. The piston crowns are engineered with a domed shape, optimizing combustion efficiency and power output. The piston skirts are designed with a full-length, split ring groove, ensuring a secure fit within the cylinder bore and reducing the risk of piston slap.

The piston rings included in this set are engineered for a precise fit and optimal sealing performance. The top ring is a compression ring designed to seal the combustion gases within the cylinder, while the second ring is an oil control ring that helps prevent oil from entering the crankcase during engine operation. The piston rings are made from a high-quality, heat-resistant material that can withstand the extreme temperatures and pressures generated during engine operation.

This piston set comes with matching piston pins, ensuring a perfect fit and smooth operation. The piston pins are made from high-strength steel and are chrome-plated to protect against wear and corrosion.

The 139666 DS Piston Set from Harley-Davidson is an excellent choice for riders who demand the best from their motorcycle. With its superior strength, durability, and performance, this piston set will help enhance the power and reliability of your Harley-Davidson engine.

For a hassle-free installation process, it's recommended to consult your Harley-Davidson dealer or a professional mechanic to ensure that the pistons are installed correctly and that all other components are in good working order. By investing in this high-quality piston set, you'll not only improve the performance of your Harley-Davidson motorcycle but also enjoy the peace of mind that comes with knowing you've made a wise investment in your ride.

Pros and Cons of Buying a 139666 DS Piston Set 3-7/16 050 for Harley Davidson Motorcycles

The 139666 DS Piston Set 3-7/16 050 is a popular option for Harley Davidson motorcycle owners looking to upgrade their engines with improved compression. In this analysis, we will discuss the potential advantages and disadvantages of purchasing this piston set.

1. Enhanced Performance: The primary reason for purchasing this piston set is the increased compression ratio, which leads to better engine performance, increased power, and improved throttle response.

2. Durability: DS pistons are known for their superior material and manufacturing quality, ensuring long-lasting performance and reduced wear and tear.

3. Customization: This piston set allows Harley Davidson owners to customize their engines to their specific needs and preferences, catering to various riding styles and engine configurations.

4. Improved Fuel Efficiency: The increased compression ratio can lead to better fuel efficiency, allowing riders to save money on fuel costs over time.

5. Wide Availability: These pistons are readily available through various dealers, making it easy for riders to find and purchase the parts they need.

1. Cost: The 139666 DS Piston Set 3-7/16 050 can be quite expensive compared to stock pistons. This cost may be a significant deterrent for some riders, especially those with tighter budgets.

2. Installation Complexity: Installing these pistons requires a high level of expertise and specialized tools, potentially leading to increased labor costs for those who do not have the necessary skills.

3. Engine Upgrades: Installing these pistons may require additional engine upgrades to ensure proper functioning and prevent potential damage. These upgrades can add to the overall cost of the project.

4. Potential Power Increase: The increased power generated by these pistons may not be desirable for all riders, especially those who prefer a more relaxed riding experience.

5. Risk of Damage: Any engine modification carries the risk of damaging the engine if not done correctly. Installing these pistons may lead to potential engine damage if not installed properly or if the engine is not adequately prepared for the increased compression ratio.

The 139666 DS Piston Set 3-7/16 050 offers several advantages, including enhanced performance, durability, customization, improved fuel efficiency, and wide availability. However, it also comes with potential disadvantages, such as high cost, installation complexity, engine upgrades, power increase, and the risk of engine damage. Ultimately, the decision to purchase this piston set depends on an individual's riding style, budget, and technical expertise. If a rider is willing to invest the time, money, and effort, the benefits of this piston set can lead to a significantly improved riding experience. However, those who prefer a more straightforward riding experience or have limited resources may find that the potential drawbacks outweigh the advantages.

For riders who are serious about optimizing their Harley Davidson's performance and are willing to invest in a high-quality piston set, the 139666 DS Piston Set 3-7/16 050 is an excellent choice. However, it is crucial to ensure that the installation is performed by a qualified mechanic to minimize the risks of damage and additional costs. Additionally, thoroughly researching the required engine upgrades and carefully considering the potential impact on the riding experience can help ensure a successful and rewarding project.

Details:

Harley Davidson FL 80 Electra Glide 1980. In.Engine Type Shovel head/ Aluminum Quantity Pair Size Over Standard .050 in. Piston rings are not included. Harley Davidson FL 1948.

DS Piston Set 3-7/16 .050 Bore 8.5:1 Compression Ratio Harley Davidson: Pistons come complete with wrist pins and cir clips sold in pairs.

part #: 139666 prices

• $39.99-$64.99

specifications pistondon:

• for models: Ds
• for makes: Harley, Davidson
• brand: Drag Specialties
• mpn: 139666
• part type: Piston Compression
• warranty details: See Manufacturer

offer pistondon:

• availability: In Stock
• started: October 17, 2025
• sold: 0
• quantity: 5
• options: Ship-to-home

shipping pistondon:

• transit: 3-5 Days
• type: Fixed
• class: Standard
• cost: $0.00
• carrier: UPS
• service: UPS Ground

returns pistondon:

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

seller pistondon:

• # reviews: 642039
• city: Grand Rapids, Michigan
• rating: 99.5%

payments pistondon:

• wallet: Apple-pay
• credit card: Discover
• other

general pistondon:

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

Drag Specialties 139666 Is Similar To:

• Drag Specialties 750766-bx-lb1 Ds-750766 (37.4% similar) Drag Specialties DS-750766 piston kit 1200CC. Available in various compression ratios. Photos are for reference only. Bore - standard bore, 9:1, pistons come complete with wrist pins and keepers sold in pairs. Actual product may differ from the item shown in photograph. Rings are not...(August 17th, 2024)
• Drag Specialties 0911-0043 (30.4% similar) Rings are not included suggest using Hastings rings. Bore - .010IN. Available in various compression ratios. Compression: 9.0:1 compression, sizing: 0.010IN. Oversize, pistons come complete with wrist pins and keepers sold in pairs. Actual product may differ from the item shown in...(August 23rd, 2024)
• Drag Specialties 0911-0083 Twin Cam 020 Inch Piston Kit Harley-davidson Electra Glide Classic Flhtc 1999-20 (41.5% similar) Part #: Drag Specialties 0911-0083 for sale...(August 23rd, 2024)
• Drag Specialties 0911-0046 Pistons Bb 005 99-06 Harley-davidson Twin Cam (54.7% similar) This occasionally happens, and is rare...(August 27th, 2024)
• Drag Specialties 0911-0082 (30.4% similar) Bore - 0.010IN. Available in various compression ratios. Bore, 9.4:1 compression, bore: 3.875IN. Photos are for reference only. Actual product may differ from the item shown in photograph. Compression: 9.4:1 compression, sizing: standard bore, pistons come complete with wrist pins and...(August 30th, 2024)
• Drag Specialties 0912-0942 Replacement Piston Ring Set 3.750 Inch Standard Bore (48.9% similar) Available in standard and oversize bore sizes. Actual product may differ from the item shown in photograph. Each set includes rings for two pistons. Designed for use with Drag Specialties replacement pistons and oem. Photos are for reference only. Feature high-quality Molly top rings...(September 14th, 2024)
• Drag Specialties 0911-0048 Big Bore Piston (36.9% similar) Free shipping offer does not include oversized parts. Keep in mind that a part can be used several times over multiple year, make, model's...(September 22nd, 2024)
• Drag Specialties 0911-0081 (30.4% similar) Bore - 0.005IN. Drag Specialties 0911-0081 piston kit 3.875IN. Rings are not included suggest using Hastings rings. Available in various compression ratios. Photos are for reference only. Compression: 9.4:1 compression, sizing: standard bore, pistons come complete with wrist pins and...(September 25th, 2024)
• Drag Specialties 0911-0041 Standard Pistons For 99-06 88 Inch Twin Cam (47.3% similar) Features: piston for twin cam motors. Specs: product name piston, bore size 3.750, - oversize standard, compression ratio 9.0:1, units pair, riding style street...(October 6th, 2024)
• Drag Specialties Ds-750754 Harley Davidson Xl 040 Piston Kit High Compression (45.2% similar) Condition is new. Drag Specialties harley davidson XL .040 piston kit DS-750754 high compression. Shipped with USPS priority mail...(October 27th, 2024)
• Drag Specialties Ds-750705 (38.4% similar) Bore - .050IN. Compression: 8.5:1 high compression, sizing: 0.050IN. Rings are not included suggest using Hastings rings. Photos are for reference only. Actual product may differ from the item shown in photograph. Oversize, pistons come complete with wrist pins and keepers sold in...(November 23rd, 2024)