{"product_id":"qsb6-7-marine-full-running-engine-copy","title":"QSB6.7 Marine Long Block Diesel Crate Engine Choate Performance","description":"\u003ch2\u003e\u003cstrong\u003eQSB6.7 Marine Long Block Engine\u003c\/strong\u003e\u003c\/h2\u003e\n\u003cp\u003eThe QSB6.7 Marine Engine is designed for reliability in harsh saltwater environments, whether for commercial fishing or recreational cruising.\u003c\/p\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003ch3\u003eKey Features and Fixes\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eVibration Mitigation:\u003c\/strong\u003e A fully balanced rotating assembly ensures your vessel runs quiet and smooth, protecting your transmission and running gear.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eEnhanced Valve Integrity:\u003c\/strong\u003e Features all-new, upgraded exhaust valves that eliminate high-heat separation, preventing catastrophic engine failure at sea.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCorrosion Resistance:\u003c\/strong\u003e Billet freeze plugs are installed to eliminate the \"rot-out\" common with standard brass or steel plugs in marine environments.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003ch3\u003eMachining Process:\u003c\/h3\u003e\n\u003cp\u003eAt Choate Engineering Performance, we don’t just \"overhaul\" marine engines, we remanufacture them to surpass original factory specifications. Our QSB6.7 marine engines undergo rigorous CNC blueprinting to correct OEM flaws, ensuring the ultimate reliability required for offshore and coastal applications.\u003c\/p\u003e\n\u003ch5\u003e\u003cstrong\u003eEngine Block Machining:\u003c\/strong\u003e\u003c\/h5\u003e\n\u003cp\u003eEach of our engine blocks are CNC blueprint machined using state-of-the-art CNC machines. This process ensures perfect dimensions, precise tolerances, and optimal alignment. This starts with decking the surface of the block to achieve the necessary flatness and smoothness (Ra 30 or better) required for flawless sealing with MLS head gaskets. The cylinders are then diamond honed to an extremely tight tolerance to match the piston diameter (within the nearest 0.0001 inch). Following honing, the main bearing bores are line honed to establish a true, straight centerline for the crankshaft. Finally, the cylinder bores are bored to a true 90 degree angle from the crankshaft centerline.\u003c\/p\u003e\n\u003ch5\u003e\u003cstrong\u003eCylinder Head Machining:\u003c\/strong\u003e\u003c\/h5\u003e\n\u003cp\u003eOur cylinder heads are fully machined and enhanced in-house to improve airflow and reliability. Each head is first magnafluxed and pressure tested to ensure they are free of any cracks or leaks. The surface is then precision decked to an extremely smooth finish, guaranteeing the necessary flatness for a perfect seal with MLS head gaskets. Internally, the valve seats are machined to optimize airflow and prevent common failures, and the entire valve train geometry is blueprinted to specific tolerances to reduce lifter preload and prolong component life.\u003c\/p\u003e\n\u003ch5\u003e\u003cstrong\u003eRotational Assembly Balancing:\u003c\/strong\u003e\u003c\/h5\u003e\n\u003cp\u003eThe balancing of the rotational assembly is crucial for eliminating vibration and maximizing engine longevity. This precision work involves checking and correcting the balance of the crankshaft, connecting rods, and pistons. The crankshaft is thoroughly checked for run-out and inspected for fatigue before being polished and ground to strict concentricity tolerances (0.0005 or less) to ensure the new bearings receive the best possible surface. Rods are inspected and conditioned, and all bearing clearances checked to ensure proper fitment with the new bearings. Each of the pistons, rings, and pin retainers are meticulously weight matched (to a tolerance of 2 grams or less) prior to crank balancing. Then the entire assembly is dynamically balanced on specialized equipment. This ensures that the engine runs smoothly, minimizing stress on the bearings, and extends the overall life of the components.\u003c\/p\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003ch3\u003eComponents and Parts:\u003c\/h3\u003e\n\u003ch5\u003e\u003cstrong\u003eEngine Core Components\u003c\/strong\u003e\u003c\/h5\u003e\n\u003cul\u003e\n\u003cli\u003eCylinder Block\u003c\/li\u003e\n\u003cli\u003eCrankshaft\u003c\/li\u003e\n\u003cli\u003eSteel Connecting Rods\u003c\/li\u003e\n\u003cli\u003eCamshaft\u003c\/li\u003e\n\u003cli\u003eMarine Pistons\u003c\/li\u003e\n\u003cli\u003eReman Cylinder Head\u003c\/li\u003e\n\u003cli\u003ePushrods\u003c\/li\u003e\n\u003cli\u003eNew Main Bearings\u003c\/li\u003e\n\u003cli\u003eNew Rod Bearings\u003c\/li\u003e\n\u003cli\u003eNew Cam Bearings\u003c\/li\u003e\n\u003cli\u003eMain Bolts\u003c\/li\u003e\n\u003cli\u003eHead Studs\u003c\/li\u003e\n\u003cli\u003eRockers\u003c\/li\u003e\n\u003cli\u003eBillet Freeze Plugs\u003c\/li\u003e\n\u003cli\u003eNew Oil Pump\u003c\/li\u003e\n\u003cli\u003eUpper Oil Pan\u003c\/li\u003e\n\u003cli\u003eLower Oil Pan\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch5\u003e\u003cstrong\u003eGaskets and Seals\u003c\/strong\u003e\u003c\/h5\u003e\n\u003cul\u003e\n\u003cli\u003eNew Head Gaskets\u003c\/li\u003e\n\u003cli\u003eRear Main Seal\u003c\/li\u003e\n\u003cli\u003eFront Gear Housing\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch5\u003e\u003cstrong\u003eCylinder Head Components\u003c\/strong\u003e\u003c\/h5\u003e\n\u003cul\u003e\n\u003cli\u003eNew Valve Guides\u003c\/li\u003e\n\u003cli\u003eNew Socket Plug\u003c\/li\u003e\n\u003cli\u003eNew Oversized Valve Seats\u003c\/li\u003e\n\u003cli\u003eNew Threaded Plugs\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003ch3\u003eMarine-Grade Confidence: 2 Year \/ 2,000 Hour Warranty\u003c\/h3\u003e\n\u003cp data-path-to-node=\"1\"\u003eWhen you’re out on the water, reliability isn’t just a luxury, it’s a necessity. At Choate, we stand behind the precision engineering of our \u003cb data-path-to-node=\"1\" data-index-in-node=\"140\"\u003eQSB6.7 Marine Engines\u003c\/b\u003e with a comprehensive \u003cb data-path-to-node=\"1\" data-index-in-node=\"183\"\u003e2-Year \/ 2,000-Hour Warranty\u003c\/b\u003e.\u003c\/p\u003e\n\u003cp data-path-to-node=\"2\"\u003eWe understand that marine environments are among the most demanding on earth. From high-idle trolling to wide-open throttle transitions, our warranty is designed to give you total peace of mind while you navigate. Whether you are a commercial operator or a recreational enthusiast, we ensure your investment is protected against defects in materials and workmanship.\u003c\/p\u003e","brand":"choateperformance","offers":[{"title":"Default Title","offer_id":66533662425392,"sku":"CEP67CML","price":12900.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0941\/2680\/1200\/files\/QSB6.7LongBlockMarineEngine.png?v=1779987672","url":"https:\/\/choateperformance.com\/products\/qsb6-7-marine-full-running-engine-copy","provider":"choateperformance","version":"1.0","type":"link"}