{"product_id":"sierra-18-70939-molded-cooling-hose-replaces-mercruiser-32-8066351-fits-4-3l-5-0l-5-7l-lx-350-mag-thermostat-housing-to-port-exhaust-manifold","title":"Sierra 18-70939 Molded Cooling Hose - Mercruiser 32-8066361 - Thermostat Housing to Starboard Exhaust Manifold, GM V-6\/V-8 305\/350","description":"\u003cp\u003eThe Sierra 18-70939 is a molded cooling system hose engineered for fresh water or raw water cooling systems on MCM\/MIE GM V-6 and V-8 (305 and 350 cid) sterndrive engines. It is designed to route coolant from the thermostat housing to the starboard exhaust manifold, and its molded construction maintains full, unrestricted water flow through the bend rather than relying on a flexible section that can kink or collapse under vacuum.\u003c\/p\u003e\u003cp\u003eConstruction is EPDM tubing with a synthetic knit reinforcement layer, giving the hose the heat and chemical resistance needed for continuous exposure to engine coolant while resisting collapse, cracking, and age-hardening. Because it is molded to the exact bend and length required for this application, installation matches the original routing without needing to force, clamp-bend, or trim a straight length of hose. Sierra engineers this hose to OEM quality so that fit, form, and function match the factory original.\u003c\/p\u003e\u003cp\u003eThis hose is specific to the starboard side application; it is not interchangeable with a port-side routing hose, which would carry a different part number. Confirm your engine is an MCM\/MIE GM V-6 or V-8 (305 or 350 cid) application before ordering to ensure correct fit.\u003c\/p\u003e\u003ch3\u003eSpecifications\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eBrand:\u003c\/strong\u003e Sierra\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eManufacturer Part Number:\u003c\/strong\u003e 18-70939\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMaterial:\u003c\/strong\u003e EPDM tubing with synthetic knit reinforcement\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eColor:\u003c\/strong\u003e White\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight:\u003c\/strong\u003e 0.64 pounds\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eApplication:\u003c\/strong\u003e Thermostat housing to starboard exhaust manifold\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSide:\u003c\/strong\u003e Starboard\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eEngine Fitment:\u003c\/strong\u003e MCM\/MIE GM V-6 \u0026amp; V-8 (305 \u0026amp; 350 cid) engines\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMercruiser Cross Reference:\u003c\/strong\u003e 32-8066361\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUPC:\u003c\/strong\u003e 808282227685\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFitment\u003c\/h3\u003e\u003cul\u003e\u003cli\u003eMCM\/MIE GM V-6 \u0026amp; V-8 (305 \u0026amp; 350 cid) engines\u003c\/li\u003e\u003c\/ul\u003e\u003ch3\u003eReplaces (OEM)\u003c\/h3\u003e\u003cul\u003e\u003cli\u003e32-8066361\u003c\/li\u003e\u003c\/ul\u003e\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eWhat engines does the Sierra 18-70939 molded hose fit?\u003c\/strong\u003e The Sierra 18-70939 fits MCM\/MIE GM V-6 and V-8 (305 and 350 cid) engines.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhere does this hose route on the engine?\u003c\/strong\u003e It routes from the thermostat housing to the starboard exhaust manifold, so it is intended for the starboard side of the engine.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWill the 18-70939 work on the port side instead?\u003c\/strong\u003e No. This hose is molded specifically for the starboard exhaust manifold routing; a port-side hose is a separate part with a different part number, so make sure you are ordering for the correct side.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs there an OEM Mercruiser number for the 18-70939?\u003c\/strong\u003e Yes, the Sierra 18-70939 cross-references to Mercruiser part number 32-8066361.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat material is the hose made from?\u003c\/strong\u003e The 18-70939 uses EPDM tubing with a synthetic knit reinforcement layer, giving it heat and chemical resistance for continuous coolant exposure.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow much does this hose weigh?\u003c\/strong\u003e The Sierra 18-70939 molded hose weighs 0.64 pounds.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat color is the 18-70939 hose?\u003c\/strong\u003e It is white.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs this a straight length of hose or pre-shaped?\u003c\/strong\u003e The 18-70939 is molded to the specific bend of the thermostat-housing-to-exhaust-manifold routing, providing full water flow through the bend rather than requiring a flexible hose to be forced into shape.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs the Sierra 18-70939 built to OEM quality?\u003c\/strong\u003e Yes, Sierra molded hoses including the 18-70939 are designed to be OEM quality and correct in fit, form, and function for the original routing.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eCan this hose be used in a raw water cooling system?\u003c\/strong\u003e Yes, the 18-70939 molded hose is designed for both fresh water and raw water cooling systems on the applicable MCM\/MIE GM V-6\/V-8 engines.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes the 18-70939 come with a warranty?\u003c\/strong\u003e Yes, this Sierra molded hose is covered under Sierra's customer satisfaction warranty.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow do I confirm the 18-70939 is the right hose for my boat?\u003c\/strong\u003e Verify your engine is an MCM\/MIE GM V-6 or V-8 in 305 or 350 cid, and that you need the thermostat-housing-to-starboard-exhaust-manifold hose, before ordering part 18-70939.\u003c\/p\u003e","brand":"Sierra","offers":[{"title":"Default Title","offer_id":48988362834139,"sku":"SIE-18-70939","price":42.01,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0839\/7586\/4539\/files\/SIE-18-70939_lg__81795.1558130616.500.750.jpg?v=1785188152","url":"https:\/\/www.goodvibesmarina.com\/products\/sierra-18-70939-molded-cooling-hose-replaces-mercruiser-32-8066351-fits-4-3l-5-0l-5-7l-lx-350-mag-thermostat-housing-to-port-exhaust-manifold","provider":"Good Vibes Marina","version":"1.0","type":"link"}