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Wiseco 3129P4 Forged Piston Kit .040 Over Chrysler Force Marine Outboard

Manufacturer

Wiseco Pistons

<h3>Wiseco: Over 80 Years of Forged Performance</h3><p><strong>Wiseco</strong> has been at the heart of performance engine building since 1941, when founder Clyde Wiseman began crafting custom pistons in his garage to meet the demands of fellow motorsports enthusiasts. What started as a passion project has grown into one of the most respected names in the performance aftermarket — and today, <a href="/765-wiseco-pistons">Wiseco</a> is widely recognized as one of the only U.S. manufacturers to forge all of its own pistons entirely in-house.</p><p>That distinction matters. The forging process starts with aerospace-grade aluminum and compresses its molecular structure, aligning the grain flow of the alloy to produce a part that is denser, tougher, and more resistant to impact and fatigue than a conventional cast piston. For high-output, high-compression, or forced-induction engines — where stresses far exceed anything a stock engine sees — that difference in material integrity is critical. Wiseco engineers leverage the latest 3D design techniques and finite element modeling software to optimize each piston for the highest strength-to-weight ratio possible, and every design is validated through in-house dyno testing before it reaches customers.</p><p>At the core of the Wiseco lineup are their <a href="/765-wiseco-pistons-engine-piston-5620">engine pistons</a>, engineered for everything from weekend street builds to full-blown NASCAR campaigns. Whether you are dropping in a set of Pro Tru Street slugs for a classic American V8 or specifying a custom sport compact piston for a boosted import, Wiseco's catalog covers an enormous range of bore sizes and applications. For riders and off-road racers, <a href="/765-wiseco-pistons-pistons-201484">powersport pistons</a> cover motorcycles, ATVs, UTVs, PWC, and snowmobiles for both 2-stroke and 4-stroke engines, each kit designed to exact tolerances for a specific engine application.</p><p>Wiseco's commitment to complete engine solutions extends well beyond the piston itself. Their <a href="/765-wiseco-pistons-engine-piston-set-10313">engine piston sets</a> bundle matched forged pistons with precision ring sets, wrist pins, and circlips, giving builders a single-source solution for a full bore's worth of rotating assembly components. When it's time for a comprehensive overhaul, <a href="/765-wiseco-pistons-engine-rebuild-kit-5316">engine rebuild kits</a> package top-end essentials — including a forged piston kit, piston rings, wrist pins, and gaskets — into a convenient, application-specific bundle that simplifies the rebuild process for both seasoned professionals and capable DIYers.</p><p>The brand also manufactures a line of <a href="/765-wiseco-pistons-engine-piston-ring-compressor-18161">engine piston ring compressors</a> — precision-machined, PTFE-coated tapered tools that make proper piston installation cleaner and more reliable. Having the right installation tool is often the difference between a correct ring seal and a costly mistake, and Wiseco's compressors are purpose-built to pair with their forged piston products.</p><p>Headquartered in Mentor, Ohio, Wiseco operates more than 150,000 square feet of state-of-the-art forging and CNC machining equipment, and its in-house dyno facility allows the team to develop and test new piston shapes, coatings, and components with the rigor that top-tier motorsport demands. From NASCAR to motocross, the brand's winning culture of precision manufacturing continues to make it the go-to choice for serious engine builders worldwide.</p>

Part Number

3129P4
07/11/2036 2:53 AM
Sale Price

$81.54

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Product Details

The Wiseco 3129P4 is a .040" oversize forged piston kit designed for Chrysler and Force two-stroke marine outboard engines with a bore size of 3.352". Wiseco's forged construction delivers superior strength and durability compared to stock cast pistons, making this an excellent choice for engine rebuilds requiring cylinder boring to the .040" oversize.

Kit Includes:

  • Forged piston
  • Wiseco piston rings
  • Wrist pin
  • Wrist pin clips (Spirolox)

Key Specifications:

  • Oversize: .040" (1.016mm) over standard
  • Bore size: 3.352"
  • Standard bore reference: 3.312"
  • Construction: Forged aluminum for maximum strength

OEM Cross-Reference Numbers: 700-F658015, 700-834798, 700-F694015

Also Replaces: 3129PS, 3129P2, 3129P3

Important Installation Note: If replacing original press-fit wrist pin pistons, wrist pin bearing p/n 131-11-126 is required. All Wiseco pistons in this series use a floating wrist pin design. In 1990, both 3.312" and 3.375" bore size blocks were produced — verify your bore size before ordering to ensure proper piston selection.

This piston kit is also compatible with L Drive motors. Available in standard, .020", .030", and .040" oversizes to accommodate various cylinder conditions.

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