{"product_id":"bbtv-639-engine-piston-ring","title":"BBTV 639 Engine Piston Ring","description":"\u003ch2\u003eEngine Piston Ring Overview\u003c\/h2\u003e\u003cp\u003eThis engine piston ring is built for classic V8 applications with an 8-cylinder layout and a standard 4.0625-inch bore. It uses grey iron top and second rings, a chrome steel-rail\/stainless expander oil ring, and phosphate surface treatment on the top and second rings for controlled break-in and wear resistance.\u003c\/p\u003e\u003ch2\u003eKey Features\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003eStandard oversize specification for matching the listed bore size.\u003c\/li\u003e\n\u003cli\u003eGrey iron top ring and second ring construction for consistent sealing performance.\u003c\/li\u003e\n\u003cli\u003eChrome-treated steel rail and stainless expander oil ring design.\u003c\/li\u003e\n\u003cli\u003ePhosphate-coated top and second ring surfaces for initial wear control.\u003c\/li\u003e\n\u003cli\u003eFits 1958-1966 Pontiac Bonneville, N\/A and other listed Pontiac, Dodge, Plymouth, and DeSoto applications.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003eDetailed Application Notes\u003c\/h2\u003e\u003cp\u003ePart number 639 is specified for a range of classic Pontiac, Dodge, Plymouth, and DeSoto engines, including 1958-1966 Pontiac Bonneville, 1958-1966 Pontiac Catalina, 1962-1966 Pontiac Grand Prix, and 1964-1966 Pontiac GTO. It also covers additional 1958 Chrysler-era applications listed in the fitment data. The ring package is configured for engines with a 4.0625-inch bore and 8 cylinders, making it a direct match for rebuild work where ring dimensions and surface finish must align with the original engine specification. Part number 639 is also cross-referenced to Monroe Shocks \u0026amp; Struts 253P and 288P for the same application.\u003c\/p\u003e\u003ch2\u003eCommon Problems This Part Addresses\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003eExcessive oil consumption from worn or damaged piston rings.\u003c\/li\u003e\n\u003cli\u003eLow compression caused by poor ring sealing.\u003c\/li\u003e\n\u003cli\u003eOil control issues from tired expander and rail components.\u003c\/li\u003e\n\u003cli\u003eBreak-in wear concerns after an engine rebuild.\u003c\/li\u003e\n\u003cli\u003eMismatch between replacement rings and the engine bore specification.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003eInstallation Notes and Quality\u003c\/h2\u003e\u003cp\u003eVerify bore size, groove dimensions, and ring end gap before assembly. Clean the piston ring grooves thoroughly and follow standard engine rebuild procedures during installation. The phosphate and chrome surface treatments are selected to support controlled seating during initial operation. Part number 639 should be matched to the exact engine application and bore specification shown in the fitment data.\u003c\/p\u003e","brand":"BBTV","offers":[{"title":"Default Title","offer_id":53706586063029,"sku":"BBTV-639","price":72.28,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0628\/1442\/1173\/files\/HA_639_Fro.jpg?v=1793947324","url":"https:\/\/www.partcatalog.com\/products\/bbtv-639-engine-piston-ring","provider":"PartCatalog","version":"1.0","type":"link"}