KB PERFORMANCE - KB595LCA.STD - Super-Duty Big Bore Piston Kit - '17-'24 Harley-Davidson Electra Glide Standard, Heritage Classic 107, Softail Slim 107
KB Performance builds this Super-Duty Big Bore Piston Kit for a 4.250" bore cylinder (sold separately) on '17-'24 Harley-Davidson engines, with oversized valve pockets accepting valves up to 4.00mm larger than stock. The Line2Line AST skirt coating starts at near-zero clearance and hones itself square during break-in, while the Type 3 hard-anodized crown and ring groove resist corrosion and micro-welding. Heavy-duty 0.9270" wrist pins and OE-style round wire locks are included alongside the pistons and rings in the standard-bore kit.
Features
- Valve pockets are designed to accept up to +4.00 mm oversized intake and exhaust valves
- Type 3 hard-anodized crown offers corrosion resistance for alcohol-added fuels
- Type 3 hard-anodized top ring groove eliminates micro-welding of ring to the groove and gives a hard-flat surface for ring to rotate on
- OE-style round wire locks are easily installed
- Heavy-duty wrist pins with true 0.9270” diameter to fit rods correctly
- Line2Line AST skirt coating starts out with a near-zero wall clearance and through the break-in period hones the cylinders to produce the correct oil wedge, keeping the piston square to the cylinder for best ring seal and quiet operation
- Kit includes pistons, rings, pins and locks
- Requires 4.250" bore cylinder sold separately.
Specs
- Piston Material: 4032 Aluminum Alloy
- Type: Big Bore
- Compression Ratio: 11.8:1
- Piston Head Shape: Domed
- Bore Size: 4.250"
- Units: Kit
- Bore - Oversize: Standard
- Product Name: Piston Kit
- Model: Super Duty
- Bore - Oversize: Standard
- Displacement: 124"
- Stroke Length: 4.375"
- Riding Style: Street
- Style: Forged
Frequently Asked Questions - KB PERFORMANCE - KB595LCA.STD - Super-Duty Big Bore Piston Kit - '17-'24 Harley-Davidson Electra Glide Standard, Heritage Classic 107, Softail Slim 107
How do I know if this part fits my vehicle?
Check the fitment information listed on this page against your exact year, make, model, and (where applicable) trim, engine size, or configuration. If your exact vehicle isn't listed, or you're not sure, use the product chat on this page or contact our support team before ordering - we're glad to help confirm fitment.
What does it mean if a product is listed as universal fit?
Universal fit means the product is designed to work across a range of vehicles, not that it's guaranteed to fit every one. Compare the listed measurements, mounting requirements, and connector or hardware specs against your specific vehicle before ordering, since some installations may need additional hardware or minor fabrication.
Where can I find installation instructions for this product?
General installation notes are provided above where available. For detailed step-by-step instructions, refer to the manufacturer's documentation included with the product, or use the product chat on this page for questions about difficulty, required tools, or whether professional installation is recommended.
What if I have more questions about this product?
Use the product chat on this page for fitment, specs, installation, and compatibility questions, or contact our support team directly for help before you order.
