{"product_id":"mhp-135-pistons-mhp-p4375-135-new-2026-pistons","title":"MHP M8 135 Stroker Pistons 4.625\" Stroke 4.313\" Bore -2.5cc  - MHP-P4313-135","description":"\u003cp\u003e\u003cstrong\u003e\u003cspan class=\"font-semibold\" data-streamdown=\"strong\"\u003eMoonshine Horsepower M8 Stroker 135 Pistons for 4.625\" Stroke\u003c\/span\u003e\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eBuilt specifically for our high-performance Moonshine Horsepower Stroker 135 packages, these pistons are engineered to deliver reliable power and durability in Milwaukee-Eight engines. Whether you’re running stock H-D Screamin’ Eagle Stage IV heads or aftermarket heads, these are the pistons we trust in every MHP 135 stroker build.\u003c\/p\u003e\n\u003cp\u003eMade from tough 2618 aluminum with a molybdenum (moly) skirt coating, they’re designed to handle serious heat, high RPM, and the demands of a stroker combination. We run these in our own engines because they hold up when you push the limits.\u003c\/p\u003e\n\u003ch3 class=\"mt-6 mb-2 font-semibold text-xl\" data-streamdown=\"heading-3\"\u003eKey Features\u003c\/h3\u003e\n\u003cul class=\"list-disc list-outside whitespace-normal ps-6 marker:text-secondary\" data-streamdown=\"unordered-list\"\u003e\n\u003cli class=\"py-1 [\u0026amp;\u0026gt;p]:inline\" data-streamdown=\"list-item\"\u003e\n\u003cspan class=\"font-semibold\" data-streamdown=\"strong\"\u003eForged 2618 aluminum construction\u003c\/span\u003e with moly skirt coating for strength and reduced friction\u003c\/li\u003e\n\u003cli class=\"py-1 [\u0026amp;\u0026gt;p]:inline\" data-streamdown=\"list-item\"\u003eOptimized for the MHP Stroker 135 combination\u003c\/li\u003e\n\u003cli class=\"py-1 [\u0026amp;\u0026gt;p]:inline\" data-streamdown=\"list-item\"\u003eClearanced for CP Carrillo rods\u003c\/li\u003e\n\u003cli class=\"py-1 [\u0026amp;\u0026gt;p]:inline\" data-streamdown=\"list-item\"\u003eClearanced for plus 4mm oversized valves\u003c\/li\u003e\n\u003cli class=\"py-1 [\u0026amp;\u0026gt;p]:inline\" data-streamdown=\"list-item\"\u003eDesigned to work with stock H-D Screamin’ Eagle Stage IV heads or aftermarket heads\u003c\/li\u003e\n\u003cli class=\"py-1 [\u0026amp;\u0026gt;p]:inline\" data-streamdown=\"list-item\"\u003eMatched to our MHP-spec Total Seal ring pack (Part # MHP-R4310A)\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3 class=\"mt-6 mb-2 font-semibold text-xl\" data-streamdown=\"heading-3\"\u003eTechnical Specifications\u003c\/h3\u003e\n\u003cdiv class=\"my-4 flex flex-col gap-2 rounded-lg border border-border bg-sidebar p-2\" data-streamdown=\"table-wrapper\"\u003e\n\u003cdiv class=\"border-collapse overflow-x-auto overflow-y-auto rounded-md border border-border bg-background\"\u003e\n\u003ctable class=\"w-full divide-y divide-border\" data-streamdown=\"table\"\u003e\n\u003cthead class=\"bg-muted\/80\" data-streamdown=\"table-header\"\u003e\n\u003ctr class=\"border-border\" data-streamdown=\"table-row\"\u003e\n\u003cth class=\"whitespace-nowrap px-4 py-2 text-left font-semibold text-sm\" data-streamdown=\"table-header-cell\"\u003eSpecification\u003c\/th\u003e\n\u003cth class=\"whitespace-nowrap px-4 py-2 text-left font-semibold text-sm\" data-streamdown=\"table-header-cell\"\u003eValue\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody class=\"divide-y divide-border\" data-streamdown=\"table-body\"\u003e\n\u003ctr class=\"border-border\" data-streamdown=\"table-row\"\u003e\n\u003ctd class=\"px-4 py-2 text-sm\" data-streamdown=\"table-cell\"\u003eBore\u003c\/td\u003e\n\u003ctd class=\"px-4 py-2 text-sm\" data-streamdown=\"table-cell\"\u003e4.313\"\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eStroke\u003c\/td\u003e\n\u003ctd\u003e4.625\"\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr class=\"border-border\" data-streamdown=\"table-row\"\u003e\n\u003ctd class=\"px-4 py-2 text-sm\" data-streamdown=\"table-cell\"\u003ePiston Diameter\u003c\/td\u003e\n\u003ctd class=\"px-4 py-2 text-sm\" data-streamdown=\"table-cell\"\u003e4.3085\"\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr class=\"border-border\" data-streamdown=\"table-row\"\u003e\n\u003ctd class=\"px-4 py-2 text-sm\" data-streamdown=\"table-cell\"\u003eCompression Height\u003c\/td\u003e\n\u003ctd class=\"px-4 py-2 text-sm\" data-streamdown=\"table-cell\"\u003e1.018\"\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr class=\"border-border\" data-streamdown=\"table-row\"\u003e\n\u003ctd class=\"px-4 py-2 text-sm\" data-streamdown=\"table-cell\"\u003eEffective Volume\u003c\/td\u003e\n\u003ctd class=\"px-4 py-2 text-sm\" data-streamdown=\"table-cell\"\u003e-2.5 cc\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr class=\"border-border\" data-streamdown=\"table-row\"\u003e\n\u003ctd class=\"px-4 py-2 text-sm\" data-streamdown=\"table-cell\"\u003eIntake Pocket Depth\u003c\/td\u003e\n\u003ctd class=\"px-4 py-2 text-sm\" data-streamdown=\"table-cell\"\u003e0.215\"\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr class=\"border-border\" data-streamdown=\"table-row\"\u003e\n\u003ctd class=\"px-4 py-2 text-sm\" data-streamdown=\"table-cell\"\u003eExhaust Pocket Depth\u003c\/td\u003e\n\u003ctd class=\"px-4 py-2 text-sm\" data-streamdown=\"table-cell\"\u003e0.195\"\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr class=\"border-border\" data-streamdown=\"table-row\"\u003e\n\u003ctd class=\"px-4 py-2 text-sm\" data-streamdown=\"table-cell\"\u003ePiston Weight\u003c\/td\u003e\n\u003ctd class=\"px-4 py-2 text-sm\" data-streamdown=\"table-cell\"\u003e413 grams\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr class=\"border-border\" data-streamdown=\"table-row\"\u003e\n\u003ctd class=\"px-4 py-2 text-sm\" data-streamdown=\"table-cell\"\u003eWrist Pin Diameter\u003c\/td\u003e\n\u003ctd class=\"px-4 py-2 text-sm\" data-streamdown=\"table-cell\"\u003e0.927\"\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003ch3 class=\"mt-6 mb-2 font-semibold text-xl\" data-streamdown=\"heading-3\"\u003e\u003c\/h3\u003e\n\u003ch3 class=\"mt-6 mb-2 font-semibold text-xl\" data-streamdown=\"heading-3\"\u003eRing Pack (Sold Separately)\u003c\/h3\u003e\n\u003cp\u003e\u003cspan class=\"font-semibold\" data-streamdown=\"strong\"\u003eMHP Spec’d Total Seal Ring Pack – \u003ca href=\"https:\/\/shop.moonshineharley.com\/collections\/pistons-and-rings\/products\/mhp-4-310-4-315-total-seal-ring-set-gas-ported-top-rings-mhp-r4310a\" title=\"MHP-R4310A\"\u003e\u003cstrong\u003ePart # MHP-R4310A\u003c\/strong\u003e\u003c\/a\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cul class=\"list-disc list-outside whitespace-normal ps-6 marker:text-secondary\" data-streamdown=\"unordered-list\"\u003e\n\u003cli class=\"py-1 [\u0026amp;\u0026gt;p]:inline\" data-streamdown=\"list-item\"\u003e0.9 mm Gas Ported Top Ring\u003c\/li\u003e\n\u003cli class=\"py-1 [\u0026amp;\u0026gt;p]:inline\" data-streamdown=\"list-item\"\u003e0.9 mm Napier Second Ring\u003c\/li\u003e\n\u003cli class=\"py-1 [\u0026amp;\u0026gt;p]:inline\" data-streamdown=\"list-item\"\u003e3.0 mm Oil Control Ring\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3 class=\"mt-6 mb-2 font-semibold text-xl\" data-streamdown=\"heading-3\"\u003eCylinder Fitment \u0026amp; Honing\u003c\/h3\u003e\n\u003cp\u003eThese pistons are sized for a \u003cspan class=\"font-semibold\" data-streamdown=\"strong\"\u003e4.313\" bore\u003c\/span\u003e. Stock Harley-Davidson 4.310\" cylinders will require honing for proper clearance.\u003c\/p\u003e\n\u003cp\u003eWe perform the finish hone in-house on our CNC Rottler using a 12-stone head setup. This gives us precise control over final size, straightness, cross-hatch angle, and the peaks and valleys of the hone surface — critical for ring seal and long-term durability. We can also hone your existing 135 cylinders for use with these pistons. Please contact Nick Zinola or Jamie Lima for this service and pricing. \u003cstrong\u003ePhone 615-274-4170\u003c\/strong\u003e\u003c\/p\u003e\n\u003ch3 class=\"mt-6 mb-2 font-semibold text-xl\" data-streamdown=\"heading-3\"\u003eWhy These Pistons\u003c\/h3\u003e\n\u003cp\u003eThese aren’t off-the-shelf parts. They’re the same pistons we use in every Moonshine Horsepower Stroker 135 engine we build. The combination of 2618 aluminum, moly coating, proper clearances, and our matched Total Seal ring pack is intended to deliver consistent performance under real-world high-output conditions.\u003c\/p\u003e\n\u003cp\u003e\u003cspan class=\"font-semibold\" data-streamdown=\"strong\"\u003eReady for serious power.\u003c\/span\u003e Contact us if you need cylinder honing or have questions about fitment in your M8 Stroker 135 build.\u003c\/p\u003e\n\u003cp\u003e \u003c\/p\u003e","brand":"Moonshine Harley-Davidson","offers":[{"title":"Default Title","offer_id":48044578406587,"sku":"MHP-P4313-135","price":689.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0101\/8085\/3857\/files\/P1362285.jpg?v=1783017911","url":"https:\/\/shop.moonshineharley.com\/products\/mhp-135-pistons-mhp-p4375-135-new-2026-pistons","provider":"Moonshine Harley-Davidson","version":"1.0","type":"link"}