{"title":"MerCruiser Cooling System Sterndrive — Closed Cooling · Closed Cooling System(18390A7 \/ A11)","description":"\u003cdiv class=\"model-catalog\"\u003e\n\u003cp\u003e\u003ca href=\"\/collections\/mercruiser-cooling-system-sterndrive-closed-cooling\"\u003eBack to MerCruiser Cooling System Sterndrive — Closed Cooling\u003c\/a\u003e\u003c\/p\u003e\n\u003cp\u003eMatch the application and restrictions below with your engine or drive before ordering.\u003c\/p\u003e\n\u003cdiv style=\"overflow-x:auto\"\u003e\u003ctable\u003e\n\u003cthead\u003e\u003ctr\u003e\n\u003cth\u003eProduct\u003c\/th\u003e\n\u003cth\u003eApplication\u003c\/th\u003e\n\u003cth\u003eCatalog reference\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\u003ctr\u003e\n\u003ctd\u003e\u003ca href=\"\/products\/27-8637251-closed-riser-gasket-set-2-pcs-for-mercruiser-v6-v8\"\u003e27-8637251 Closed Riser Gasket Set (2 Pcs) for MerCruiser V6 \u0026amp; V8\u003c\/a\u003e\u003c\/td\u003e\n\u003ctd\u003eCooling: Closed Cooling\u003c\/td\u003e\n\u003ctd\u003e\u003cspan class=\"catalog-reference\"\u003eCatalog parts list · Ref. 26\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\u003c\/tbody\u003e\n\u003c\/table\u003e\u003c\/div\u003e\n\u003c\/div\u003e","products":[{"product_id":"27-8637251-closed-riser-gasket-set-2-pcs-for-mercruiser-v6-v8","title":"27-8637251 Closed Riser Gasket Set (2 Pcs) for MerCruiser V6 \u0026 V8","description":"\u003cdiv style=\"width:100%;max-width:960px;margin:0 auto;box-sizing:border-box;font-family:Arial,Helvetica,sans-serif;font-size:16px;line-height:1.75;color:#293a35;background:#ffffff;overflow-wrap:anywhere;\"\u003e\n  \u003csection style=\"padding:28px 24px;margin:0 0 40px;border-top:5px solid #234d40;background:#f5f3ec;box-sizing:border-box;\"\u003e\n    \u003cp style=\"margin:0 0 14px;color:#456052;font-size:12px;line-height:1.6;font-weight:700;letter-spacing:1.4px;text-transform:uppercase;\"\u003eSERDAMARINE \/ MARINE EXHAUST PARTS\u003c\/p\u003e\n    \u003ch2 style=\"margin:0 0 18px;color:#203e32;font-family:Georgia,Times,serif;font-size:clamp(25px,4vw,34px);font-weight:400;line-height:1.25;\"\u003eExhaust Manifold Elbow Riser Gasket Set (2 Pieces) — Closed \/ Block-Off Cooling Configuration\u003c\/h2\u003e\n    \u003cp style=\"margin:0 0 14px;\"\u003eThis two-piece exhaust manifold-to-elbow\/riser gasket set (referencing MerCruiser 27-8637251) is designed for specified MerCruiser GM V6 and V8 stern drive and inboard engines with center-riser exhaust manifolds and closed (fresh water) cooling systems. It applies to wet-joint center-riser arrangements from 1981 or 1983 depending on engine family, as well as GM V6 and V8 Small Block Dry Joint \"Alternative\" systems (0M serial numbers and up); it is not the open-flow or restricted-flow gasket version.\u003c\/p\u003e\n  \u003c\/section\u003e\n\n  \u003csection style=\"margin:0 0 40px;\"\u003e\n    \u003ch2 style=\"margin:0 0 18px;padding:0 0 10px;border-bottom:1px solid #bdc9c0;color:#234d40;font-family:Georgia,Times,serif;font-size:25px;font-weight:400;line-height:1.35;\"\u003eConfiguration \u0026amp; Specifications\u003c\/h2\u003e\n    \u003ctable style=\"width:100%;table-layout:fixed;border-collapse:collapse;text-align:left;\"\u003e\n      \u003ctbody\u003e\n        \u003ctr\u003e\n          \u003cth scope=\"row\" style=\"width:36%;padding:13px 10px 13px 0;border-bottom:1px solid #e0e5df;vertical-align:top;text-align:left;font-size:14px;font-weight:700;color:#456052;\"\u003eJoint Position\u003c\/th\u003e\n          \u003ctd style=\"padding:13px 0 13px 10px;border-bottom:1px solid #e0e5df;vertical-align:top;\"\u003eExhaust manifold to elbow \/ riser (center-exit \/ center-riser manifold configuration)\u003c\/td\u003e\n        \u003c\/tr\u003e\n        \u003ctr\u003e\n          \u003cth scope=\"row\" style=\"width:36%;padding:13px 10px 13px 0;border-bottom:1px solid #e0e5df;vertical-align:top;text-align:left;font-size:14px;font-weight:700;color:#456052;\"\u003eFlow \/ Cooling Configuration\u003c\/th\u003e\n          \u003ctd style=\"padding:13px 0 13px 10px;border-bottom:1px solid #e0e5df;vertical-align:top;\"\u003eClosed (block-off) configuration for MerCruiser closed \/ fresh water cooling systems\u003c\/td\u003e\n        \u003c\/tr\u003e\n        \u003ctr\u003e\n          \u003cth scope=\"row\" style=\"width:36%;padding:13px 10px 13px 0;border-bottom:1px solid #e0e5df;vertical-align:top;text-align:left;font-size:14px;font-weight:700;color:#456052;\"\u003eExhaust Joint Compatibility\u003c\/th\u003e\n          \u003ctd style=\"padding:13px 0 13px 10px;border-bottom:1px solid #e0e5df;vertical-align:top;\"\u003eConventional Wet Joint center-riser systems and GM V6 \/ V8 Small Block Dry Joint \"Alternative\" replacement systems\u003c\/td\u003e\n        \u003c\/tr\u003e\n      \u003c\/tbody\u003e\n    \u003c\/table\u003e\n  \u003c\/section\u003e\n\n  \u003csection style=\"margin:0 0 40px;\"\u003e\n    \u003ch2 style=\"margin:0 0 18px;padding:0 0 10px;border-bottom:1px solid #bdc9c0;color:#234d40;font-family:Georgia,Times,serif;font-size:25px;font-weight:400;line-height:1.35;\"\u003eEngine Applications\u003c\/h2\u003e\n    \u003cp style=\"margin:0 0 14px;\"\u003eApplies to MerCruiser GM-based V6 and V8 stern drive (rear transmission) and inboard engines equipped with center-exit exhaust manifolds and the MerCruiser closed (fresh water) cooling system. Match the engine family, serial number range, cooling-system gasket position, and whether the installed exhaust is a conventional wet-joint center-riser or a Dry Joint \"Alternative\" system before ordering.\u003c\/p\u003e\n    \u003cul style=\"list-style:none;margin:0;padding:0;\"\u003e\n      \u003cli style=\"margin:0;padding:17px 0;border-bottom:1px solid #dce3dc;\"\u003e\n        \u003cstrong\u003eMerCruiser Model 175–205 (GM V6, 229 \/ 262 CID)\u003c\/strong\u003e — Years: 1983 to 0M serial numbers. Exhaust configuration: Center Riser, Wet Joint. Cooling configuration: Closed (Fresh Water Cooling).\n        \u003cspan style=\"display:block;margin:6px 0 0;color:#59421f;font-size:13px;font-weight:700;\"\u003eFits when specified\u003c\/span\u003e\n      \u003c\/li\u003e\n      \u003cli style=\"margin:0;padding:17px 0;border-bottom:1px solid #dce3dc;\"\u003e\n        \u003cstrong\u003eMerCruiser Model 200–320 (GM V8 Small Block, 305 \/ 350 \/ 377 CID)\u003c\/strong\u003e — Years: 1983 to 0M serial numbers. Exhaust configuration: Center Riser, Wet Joint. Cooling configuration: Closed (Fresh Water Cooling).\n        \u003cspan style=\"display:block;margin:6px 0 0;color:#59421f;font-size:13px;font-weight:700;\"\u003eFits when specified\u003c\/span\u003e\n      \u003c\/li\u003e\n      \u003cli style=\"margin:0;padding:17px 0;border-bottom:1px solid #dce3dc;\"\u003e\n        \u003cstrong\u003eMerCruiser Model 330–370 (GM V8 Big Block, 454 \/ 502 CID)\u003c\/strong\u003e — Years: 1981 and up. Exhaust configuration: Center Riser, Wet Joint. Cooling configuration: Closed (Fresh Water Cooling).\n        \u003cspan style=\"display:block;margin:6px 0 0;color:#59421f;font-size:13px;font-weight:700;\"\u003eFits when specified\u003c\/span\u003e\n      \u003c\/li\u003e\n      \u003cli style=\"margin:0;padding:17px 0;border-bottom:1px solid #dce3dc;\"\u003e\n        \u003cstrong\u003eMerCruiser GM V6 \/ V8 Small Block — Dry Joint \"Alternative\" System\u003c\/strong\u003e — Serial numbers: 0M and up. Exhaust configuration: Center Riser, Dry Joint \"Alternative\" replacement system using the specified fresh-water-cooling closed gasket position.\n        \u003cspan style=\"display:block;margin:6px 0 0;color:#59421f;font-size:13px;font-weight:700;\"\u003eFits when specified\u003c\/span\u003e\n      \u003c\/li\u003e\n    \u003c\/ul\u003e\n    \u003cdiv style=\"margin:18px 0 0;padding:14px 16px;border-left:3px solid #8c622b;background:#faf5e9;color:#59421f;\"\u003e\n      \u003ch3 style=\"margin:0 0 10px;color:#234d40;font-size:17px;line-height:1.5;font-weight:700;\"\u003eNot Suitable For\u003c\/h3\u003e\n      \u003cp style=\"margin:0 0 14px;\"\u003e\u003cstrong\u003eOpen-flow or restricted-flow joint positions:\u003c\/strong\u003e This is the closed (block-off) gasket version for fresh water cooling; do not install in positions requiring open\/full-flow or restrictor water-passage gaskets.\u003c\/p\u003e\n      \u003cp style=\"margin:0;\"\u003e\u003cstrong\u003eStandard OEM Dry Joint systems outside the \"Alternative\" configuration:\u003c\/strong\u003e Not a universal fit for every OEM dry-joint exhaust system. Do not select this gasket solely because an engine has a dry-joint exhaust manifold.\u003c\/p\u003e\n    \u003c\/div\u003e\n  \u003ch3 style=\"font-size:17px;margin:20px 0 10px;color:#143b31;\"\u003eAdditional model-specific applications\u003c\/h3\u003e\n\u003cul style=\"padding-left:20px;line-height:1.7;\"\u003e\n\u003cli\u003eMerCruiser MODEL 175-205 — GM V6, 229 CID, Wet Joint, Center Riser, Closed \/ Fresh Water Cooling; Year \/ serial number condition “1983 - 0M SN#’s.”\u003c\/li\u003e\n\u003cli\u003eMerCruiser MODEL 175-205 — GM V6, 262 CID, Wet Joint, Center Riser, Closed \/ Fresh Water Cooling; Year \/ serial number condition “1983 - 0M SN#’s.”\u003c\/li\u003e\n\u003cli\u003eMerCruiser MODEL 200-320 — GM V8 Small Block, 305 CID, Wet Joint, Center Riser, Closed \/ Fresh Water Cooling; Year \/ serial number condition “1983 - 0M SN#’s.”\u003c\/li\u003e\n\u003cli\u003eMerCruiser MODEL 200-320 — GM V8 Small Block, 350 CID, Wet Joint, Center Riser, Closed \/ Fresh Water Cooling; Year \/ serial number condition “1983 - 0M SN#’s.”\u003c\/li\u003e\n\u003cli\u003eMerCruiser MODEL 200-320 — GM V8 Small Block, 377 CID, Wet Joint, Center Riser, Closed \/ Fresh Water Cooling; Year \/ serial number condition “1983 - 0M SN#’s.”\u003c\/li\u003e\n\u003cli\u003eMerCruiser MODEL 330-370 — GM V8 Big Block, 454 CID, Wet Joint, Center Riser, Closed \/ Fresh Water Cooling; from 1981 onward,\u003c\/li\u003e\n\u003cli\u003eMerCruiser MODEL 330-370 — GM V8 Big Block, 502 CID, Wet Joint, Center Riser, Closed \/ Fresh Water Cooling; from 1981 onward,\u003c\/li\u003e\n\u003cli\u003eMerCruiser GM V6 — Dry Joint “Alternative”, Fresh Water Cooling gasket position; serial condition “0M SN#’s \u0026amp; UP.”\u003c\/li\u003e\n\u003cli\u003eMerCruiser GM V8 Small Block — Dry Joint “Alternative”, Fresh Water Cooling gasket position; serial condition “0M SN#’s \u0026amp; UP.”\u003c\/li\u003e\n\u003cli\u003eMerCruiser GM-manufactured V6 inboard engines with center-exit exhaust manifolds and MerCruiser closed cooling.\u003c\/li\u003e\n\u003cli\u003eMerCruiser GM-manufactured V8 inboard engines with center-exit exhaust manifolds and MerCruiser closed cooling.\u003c\/li\u003e\n\u003cli\u003eMerCruiser GM-manufactured V6, application described as “rear transmissions,” with center-exit exhaust manifolds and MerCruiser closed cooling.\u003c\/li\u003e\n\u003cli\u003eMerCruiser GM-manufactured V8, application described as “rear transmissions,” with center-exit exhaust manifolds and MerCruiser closed cooling.\u003c\/li\u003e\n\u003c\/ul\u003e\u003c\/section\u003e\n\n  \u003csection style=\"margin:0 0 40px;\"\u003e\n    \u003ch2 style=\"margin:0 0 18px;padding:0 0 10px;border-bottom:1px solid #bdc9c0;color:#234d40;font-family:Georgia,Times,serif;font-size:25px;font-weight:400;line-height:1.35;\"\u003eReference Numbers\u003c\/h2\u003e\n    \u003cp style=\"margin:0 0 14px;\"\u003eThe numbers below are provided for part identification and cross-reference only; they do not imply manufacturer identity or guaranteed interchangeability across different cooling configurations.\u003c\/p\u003e\n    \u003ctable style=\"width:100%;table-layout:fixed;border-collapse:collapse;text-align:left;\"\u003e\n      \u003ctbody\u003e\n        \u003ctr\u003e\n          \u003cth scope=\"row\" style=\"width:36%;padding:13px 10px 13px 0;border-bottom:1px solid #e0e5df;vertical-align:top;text-align:left;font-size:14px;font-weight:700;color:#456052;\"\u003eMerCruiser Stern \/ Out Drive\u003c\/th\u003e\n          \u003ctd style=\"padding:13px 0 13px 10px;border-bottom:1px solid #e0e5df;vertical-align:top;\"\u003e8637251, 27-8637251, 863725, 27-863725, 860231, 27-860231, 41811, 27-41811, 87918, 87918A1\u003c\/td\u003e\n        \u003c\/tr\u003e\n        \u003ctr\u003e\n          \u003cth scope=\"row\" style=\"width:36%;padding:13px 10px 13px 0;border-bottom:1px solid #e0e5df;vertical-align:top;text-align:left;font-size:14px;font-weight:700;color:#456052;\"\u003eMercury Mariner\u003c\/th\u003e\n          \u003ctd style=\"padding:13px 0 13px 10px;border-bottom:1px solid #e0e5df;vertical-align:top;\"\u003e27-863725, 27-860231, 27-41811\u003c\/td\u003e\n        \u003c\/tr\u003e\n        \u003ctr\u003e\n          \u003cth scope=\"row\" style=\"width:36%;padding:13px 10px 13px 0;border-bottom:1px solid #e0e5df;vertical-align:top;text-align:left;font-size:14px;font-weight:700;color:#456052;\"\u003eOMC\u003c\/th\u003e\n          \u003ctd style=\"padding:13px 0 13px 10px;border-bottom:1px solid #e0e5df;vertical-align:top;\"\u003e0502988, 0508715\u003c\/td\u003e\n        \u003c\/tr\u003e\n        \u003ctr\u003e\n          \u003cth scope=\"row\" style=\"width:36%;padding:13px 10px 13px 0;border-bottom:1px solid #e0e5df;vertical-align:top;text-align:left;font-size:14px;font-weight:700;color:#456052;\"\u003eSierra\u003c\/th\u003e\n          \u003ctd style=\"padding:13px 0 13px 10px;border-bottom:1px solid #e0e5df;vertical-align:top;\"\u003e18-0672, 18-0672-9\u003c\/td\u003e\n        \u003c\/tr\u003e\n        \u003ctr\u003e\n          \u003cth scope=\"row\" style=\"width:36%;padding:13px 10px 13px 0;border-bottom:1px solid #e0e5df;vertical-align:top;text-align:left;font-size:14px;font-weight:700;color:#456052;\"\u003eGLM\u003c\/th\u003e\n          \u003ctd style=\"padding:13px 0 13px 10px;border-bottom:1px solid #e0e5df;vertical-align:top;\"\u003e30220\u003c\/td\u003e\n        \u003c\/tr\u003e\n        \u003ctr\u003e\n          \u003cth scope=\"row\" style=\"width:36%;padding:13px 10px 13px 0;border-bottom:1px solid #e0e5df;vertical-align:top;text-align:left;font-size:14px;font-weight:700;color:#456052;\"\u003eMallory\u003c\/th\u003e\n          \u003ctd style=\"padding:13px 0 13px 10px;border-bottom:1px solid #e0e5df;vertical-align:top;\"\u003e9-61422\u003c\/td\u003e\n        \u003c\/tr\u003e\n        \u003ctr\u003e\n          \u003cth scope=\"row\" style=\"width:36%;padding:13px 10px 13px 0;border-bottom:1px solid #e0e5df;vertical-align:top;text-align:left;font-size:14px;font-weight:700;color:#456052;\"\u003eOther Reference Numbers\u003c\/th\u003e\n          \u003ctd style=\"padding:13px 0 13px 10px;border-bottom:1px solid #e0e5df;vertical-align:top;\"\u003e8503-GB, MC-47-27-41811\u003c\/td\u003e\n        \u003c\/tr\u003e\n      \u003c\/tbody\u003e\n    \u003c\/table\u003e\n  \u003c\/section\u003e\n\n  \u003csection style=\"margin:0 0 40px;\"\u003e\n    \u003ch2 style=\"margin:0 0 18px;padding:0 0 10px;border-bottom:1px solid #bdc9c0;color:#234d40;font-family:Georgia,Times,serif;font-size:25px;font-weight:400;line-height:1.35;\"\u003eSupplied Parts\u003c\/h2\u003e\n    \u003cul style=\"margin:0;padding-left:22px;\"\u003e\n      \u003cli style=\"margin:0 0 12px;\"\u003e2 × Exhaust Manifold Elbow \/ Riser Gasket (Closed \/ Fresh Water Cooling configuration)\u003c\/li\u003e\n    \u003c\/ul\u003e\n  \u003c\/section\u003e\n\n  \u003csection style=\"margin:0 0 40px;\"\u003e\n    \u003ch2 style=\"margin:0 0 18px;padding:0 0 10px;border-bottom:1px solid #bdc9c0;color:#234d40;font-family:Georgia,Times,serif;font-size:25px;font-weight:400;line-height:1.35;\"\u003eService \u0026amp; Installation Notes\u003c\/h2\u003e\n    \u003cp style=\"margin:0 0 14px;\"\u003eGeneral service guidance only. Use the service manual for your exact engine and exhaust configuration.\u003c\/p\u003e\n    \u003col style=\"margin:0;padding-left:22px;list-style-type:decimal;\"\u003e\n      \u003cli style=\"margin:0 0 12px;\"\u003eShut off the engine, allow the exhaust system to cool completely, and disconnect the battery or disable ignition to prevent accidental starting.\u003c\/li\u003e\n      \u003cli style=\"margin:0 0 12px;\"\u003eDrain the cooling passages in the exhaust manifold and elbow\/riser according to the engine service manual before loosening joint fasteners, and support heavy exhaust components during removal.\u003c\/li\u003e\n      \u003cli style=\"margin:0 0 12px;\"\u003eRemove all old gasket material and inspect both the manifold and elbow\/riser mating surfaces for flatness, corrosion, or pitting while protecting the sealing surfaces from gouges.\u003c\/li\u003e\n      \u003cli style=\"margin:0 0 12px;\"\u003eVerify that the closed (block-off) gasket matches the required cooling circuit position for your closed-cooling system before reassembling and tightening fasteners to the factory specification.\u003c\/li\u003e\n      \u003cli style=\"margin:0 0 12px;\"\u003eAfter installation, run the engine with proper cooling water supply and inspect the manifold-to-riser joint for coolant, water, or exhaust leaks; stop the engine immediately and inspect if any leakage or abnormal temperature occurs.\u003c\/li\u003e\n    \u003c\/ol\u003e\n  \u003c\/section\u003e\n\n  \u003csection style=\"margin:0 0 40px;padding:24px;border-top:1px solid #bdc9c0;border-bottom:1px solid #bdc9c0;background:#f5f3ec;box-sizing:border-box;\"\u003e\n    \u003ch2 style=\"margin:0 0 18px;padding:0 0 10px;border-bottom:1px solid #bdc9c0;color:#234d40;font-family:Georgia,Times,serif;font-size:25px;font-weight:400;line-height:1.35;\"\u003eThe Serdamarine Approach\u003c\/h2\u003e\n    \u003cp style=\"margin:0;\"\u003eExhaust parts need a configuration match. Serdamarine focuses on marine exhaust manifolds and their related service parts. Application details, connection requirements and public reference numbers are presented together to support part selection.\u003c\/p\u003e\n  \u003c\/section\u003e\n\n  \u003csection style=\"margin:0 0 40px;\"\u003e\n    \u003ch2 style=\"margin:0 0 18px;padding:0 0 10px;border-bottom:1px solid #bdc9c0;color:#234d40;font-family:Georgia,Times,serif;font-size:25px;font-weight:400;line-height:1.35;\"\u003eQuestions Before Replacement\u003c\/h2\u003e\n    \u003cdiv style=\"margin:0;padding:18px 0;border-bottom:1px solid #dce3dc;\"\u003e\n      \u003ch3 style=\"margin:0 0 10px;color:#234d40;font-size:17px;line-height:1.5;font-weight:700;\"\u003eCan this gasket be used on open-flow or restricted-flow manifold-to-elbow joints?\u003c\/h3\u003e\n      \u003cp style=\"margin:0;\"\u003eNo. This gasket is the closed (block-off) version for specified MerCruiser closed (fresh water) cooling applications. Open-flow and restricted-flow gaskets have different water-passage cutouts and are identified under separate part numbers.\u003c\/p\u003e\n    \u003c\/div\u003e\n    \u003cdiv style=\"margin:0;padding:18px 0;border-bottom:1px solid #dce3dc;\"\u003e\n      \u003ch3 style=\"margin:0 0 10px;color:#234d40;font-size:17px;line-height:1.5;font-weight:700;\"\u003eDoes this fit all MerCruiser Dry Joint exhaust manifolds?\u003c\/h3\u003e\n      \u003cp style=\"margin:0;\"\u003eNo. For dry-joint systems, this gasket applies only to the GM V6 and V8 Small Block Dry Joint \"Alternative\" replacement system (0M serial numbers and up) where this specific fresh-water-cooling closed gasket is required. It is not a universal fit for original OEM dry-joint manifolds.\u003c\/p\u003e\n    \u003c\/div\u003e\n  \u003c\/section\u003e\n\u003c\/div\u003e","brand":"Serdamarine","offers":[{"title":"Default Title","offer_id":45171576307763,"sku":"23GT297*2","price":16.8,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0699\/2930\/4115\/files\/marine-exhaust-part-28aaf6cea101517e.png?v=1792750277"}],"url":"https:\/\/serdamarine.com\/collections\/mercruiser-cooling-system-sterndrive-closed-cooling-closed-cooling-system-18390a7-a11.oembed","provider":"我的商店","version":"1.0","type":"link"}