{"product_id":"ums-5-cylinder-55cc-petrol-radial-engine-4-stroke-scale-aircraft-powerplant","title":"UMS 5-Cylinder 55cc Petrol Radial Engine – 4-Stroke Scale Aircraft Powerplant","description":"\u003cp data-start=\"301\" data-end=\"615\"\u003eThe \u003cstrong data-start=\"305\" data-end=\"349\"\u003eUMS 5-Cylinder 55cc Petrol Radial Engine\u003c\/strong\u003e delivers authentic radial appearance, smooth 4-stroke performance, and dependable engineering in a compact, lightweight format. Designed for smaller scale aircraft, this ready-to-run petrol radial offers realistic sound, refined machining, and long-term durability.\u003c\/p\u003e\n\u003ch2 data-start=\"622\" data-end=\"650\"\u003e\u003cstrong data-start=\"625\" data-end=\"648\"\u003eProduct Description\u003c\/strong\u003e\u003c\/h2\u003e\n\u003cp data-start=\"652\" data-end=\"955\"\u003eThe \u003cstrong data-start=\"656\" data-end=\"693\"\u003eUMS 5-Cylinder 55cc Radial Engine\u003c\/strong\u003e is the smallest in the UMS 5-cylinder radial range, offering true radial realism in a compact and lightweight package. Perfect for detailed scale models and vintage aircraft builds, it combines authentic sound and appearance with modern manufacturing precision.\u003c\/p\u003e\n\u003cp data-start=\"957\" data-end=\"1273\"\u003eWith a \u003cstrong data-start=\"964\" data-end=\"985\"\u003e55cc displacement\u003c\/strong\u003e, this engine provides reliable and efficient power for lightweight scale aircraft where balance and weight are critical. Supplied \u003cstrong data-start=\"1116\" data-end=\"1132\"\u003eready to run\u003c\/strong\u003e, it includes an exhaust collector ring, spark plugs, electronic ignition system, and a sturdy engine mount for straightforward installation.\u003c\/p\u003e\n\u003cp data-start=\"1275\" data-end=\"1528\"\u003eAll major components are \u003cstrong data-start=\"1300\" data-end=\"1344\"\u003eCNC-machined from aluminium or bar stock\u003c\/strong\u003e, ensuring accuracy, repeatability, and durability. The \u003cstrong data-start=\"1400\" data-end=\"1454\"\u003eaircraft-grade alloy cylinder heads and crankcases\u003c\/strong\u003e provide strength while maintaining an excellent strength-to-weight ratio.\u003c\/p\u003e\n\u003cp data-start=\"1530\" data-end=\"1870\"\u003eA \u003cstrong data-start=\"1532\" data-end=\"1572\"\u003eheavy-duty double-bearing crankshaft\u003c\/strong\u003e ensures smooth operation and extended service life. Billet aluminium pistons fitted with hardened steel rings operate within \u003cstrong data-start=\"1698\" data-end=\"1729\"\u003ehard-chromed cylinder bores\u003c\/strong\u003e, reducing friction and enhancing wear resistance. Hardened steel camshafts ensure reliable valve timing and long-term operational stability.\u003c\/p\u003e\n\u003cp data-start=\"1872\" data-end=\"2079\"\u003eDesigned to operate on \u003cstrong data-start=\"1895\" data-end=\"1919\"\u003e87–110 octane petrol\u003c\/strong\u003e with a \u003cstrong data-start=\"1927\" data-end=\"1955\"\u003e32:1 fuel-to-oil mixture\u003c\/strong\u003e, this compact radial engine provides dependable 4-stroke performance and authentic scale character for discerning builders.\u003c\/p\u003e\n\u003ch2 data-start=\"2086\" data-end=\"2105\"\u003e\u003cstrong data-start=\"2089\" data-end=\"2105\"\u003eKey Features\u003c\/strong\u003e\u003c\/h2\u003e\n\u003cul data-start=\"2107\" data-end=\"2784\"\u003e\n\u003cli data-start=\"2107\" data-end=\"2176\"\u003e\n\u003cp data-start=\"2109\" data-end=\"2176\"\u003e5-cylinder 4-stroke radial engine with authentic scale appearance\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"2177\" data-end=\"2247\"\u003e\n\u003cp data-start=\"2179\" data-end=\"2247\"\u003e55cc displacement ideal for lightweight and smaller scale aircraft\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"2248\" data-end=\"2329\"\u003e\n\u003cp data-start=\"2250\" data-end=\"2329\"\u003eReady-to-run package including ignition, plugs, collector ring \u0026amp; engine mount\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"2330\" data-end=\"2393\"\u003e\n\u003cp data-start=\"2332\" data-end=\"2393\"\u003ePrecision CNC-machined aluminium and bar stock construction\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"2394\" data-end=\"2448\"\u003e\n\u003cp data-start=\"2396\" data-end=\"2448\"\u003eAircraft-grade alloy cylinder heads and crankcases\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"2449\" data-end=\"2510\"\u003e\n\u003cp data-start=\"2451\" data-end=\"2510\"\u003eHeavy-duty double-bearing crankshaft for smooth operation\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"2511\" data-end=\"2565\"\u003e\n\u003cp data-start=\"2513\" data-end=\"2565\"\u003eBillet aluminium pistons with hardened steel rings\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"2566\" data-end=\"2629\"\u003e\n\u003cp data-start=\"2568\" data-end=\"2629\"\u003eHard-chromed cylinder bores for durability and reduced wear\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"2630\" data-end=\"2684\"\u003e\n\u003cp data-start=\"2632\" data-end=\"2684\"\u003eHardened steel camshafts for reliable valve timing\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"2685\" data-end=\"2732\"\u003e\n\u003cp data-start=\"2687\" data-end=\"2732\"\u003eUser-friendly choke and throttle bellcranks\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"2733\" data-end=\"2784\"\u003e\n\u003cp data-start=\"2735\" data-end=\"2784\"\u003eCompatible with 87–110 octane petrol (32:1 mix)\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2 data-start=\"2791\" data-end=\"2809\"\u003e\u003cstrong data-start=\"2794\" data-end=\"2809\"\u003ePerfect For\u003c\/strong\u003e\u003c\/h2\u003e\n\u003cul data-start=\"2811\" data-end=\"3006\"\u003e\n\u003cli data-start=\"2811\" data-end=\"2840\"\u003e\n\u003cp data-start=\"2813\" data-end=\"2840\"\u003eSmaller scale RC warbirds\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"2841\" data-end=\"2880\"\u003e\n\u003cp data-start=\"2843\" data-end=\"2880\"\u003eVintage and classic aircraft builds\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"2881\" data-end=\"2923\"\u003e\n\u003cp data-start=\"2883\" data-end=\"2923\"\u003eLightweight radial engine applications\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"2924\" data-end=\"2967\"\u003e\n\u003cp data-start=\"2926\" data-end=\"2967\"\u003eBuilders seeking authentic radial sound\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"2968\" data-end=\"3006\"\u003e\n\u003cp data-start=\"2970\" data-end=\"3006\"\u003ePrecision scale modelling projects\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2 data-start=\"3013\" data-end=\"3034\"\u003e\u003cstrong data-start=\"3016\" data-end=\"3034\"\u003eSpecifications\u003c\/strong\u003e\u003c\/h2\u003e\n\u003cp data-start=\"3036\" data-end=\"3374\"\u003e\u003cstrong data-start=\"3036\" data-end=\"3052\"\u003eEngine Type:\u003c\/strong\u003e 4-Stroke\u003cbr data-start=\"3061\" data-end=\"3064\"\u003e\u003cstrong data-start=\"3064\" data-end=\"3078\"\u003eCylinders:\u003c\/strong\u003e 5 (ABC Type)\u003cbr data-start=\"3091\" data-end=\"3094\"\u003e\u003cstrong data-start=\"3094\" data-end=\"3111\"\u003eDisplacement:\u003c\/strong\u003e 55cc\u003cbr data-start=\"3116\" data-end=\"3119\"\u003e\u003cstrong data-start=\"3119\" data-end=\"3128\"\u003eBore:\u003c\/strong\u003e 23.7mm\u003cbr data-start=\"3135\" data-end=\"3138\"\u003e\u003cstrong data-start=\"3138\" data-end=\"3149\"\u003eStroke:\u003c\/strong\u003e 25mm\u003cbr data-start=\"3154\" data-end=\"3157\"\u003e\u003cstrong data-start=\"3157\" data-end=\"3176\"\u003eApprox. Thrust:\u003c\/strong\u003e 7.5kgf @ 20×8 SEP prop\u003cbr data-start=\"3199\" data-end=\"3202\"\u003e\u003cstrong data-start=\"3202\" data-end=\"3216\"\u003eRPM Range:\u003c\/strong\u003e 1,000 – 6,000\u003cbr data-start=\"3230\" data-end=\"3233\"\u003e\u003cstrong data-start=\"3233\" data-end=\"3271\"\u003eWeight (with silencer \u0026amp; ignition):\u003c\/strong\u003e Approx. 2.35kg\u003cbr data-start=\"3286\" data-end=\"3289\"\u003e\u003cstrong data-start=\"3289\" data-end=\"3309\"\u003eEngine Diameter:\u003c\/strong\u003e 201mm\u003cbr data-start=\"3315\" data-end=\"3318\"\u003e\u003cstrong data-start=\"3318\" data-end=\"3336\"\u003eEngine Length:\u003c\/strong\u003e 142mm\u003cbr data-start=\"3342\" data-end=\"3345\"\u003e\u003cstrong data-start=\"3345\" data-end=\"3372\"\u003eRecommended Propellers:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul data-start=\"3375\" data-end=\"3614\"\u003e\n\u003cli data-start=\"3375\" data-end=\"3391\"\u003e\n\u003cp data-start=\"3377\" data-end=\"3391\"\u003e2-Blade 17×8\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"3392\" data-end=\"3409\"\u003e\n\u003cp data-start=\"3394\" data-end=\"3409\"\u003e2-Blade 17×10\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"3410\" data-end=\"3427\"\u003e\n\u003cp data-start=\"3412\" data-end=\"3427\"\u003e2-Blade 17×12\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"3428\" data-end=\"3444\"\u003e\n\u003cp data-start=\"3430\" data-end=\"3444\"\u003e2-Blade 18×6\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"3445\" data-end=\"3461\"\u003e\n\u003cp data-start=\"3447\" data-end=\"3461\"\u003e2-Blade 18×8\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"3462\" data-end=\"3614\"\u003e\n\u003cp data-start=\"3464\" data-end=\"3614\"\u003e2-Blade 20×8\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp data-start=\"3464\" data-end=\"3614\"\u003e\u003cstrong data-start=\"3479\" data-end=\"3496\"\u003eMuffler Type:\u003c\/strong\u003e Collector Ring\u003cbr data-start=\"3511\" data-end=\"3514\"\u003e\u003cstrong data-start=\"3514\" data-end=\"3529\"\u003eSpark Plug:\u003c\/strong\u003e 1\/4-32\u003cbr data-start=\"3536\" data-end=\"3539\"\u003e\u003cstrong data-start=\"3539\" data-end=\"3555\"\u003eCarburettor:\u003c\/strong\u003e UMS T2\u003cbr data-start=\"3562\" data-end=\"3565\"\u003e\u003cstrong data-start=\"3565\" data-end=\"3579\"\u003eFuel Type:\u003c\/strong\u003e Petrol (87–110 octane, 32:1 mix)\u003c\/p\u003e\n\u003ch3 data-end=\"3529\" data-start=\"3491\"\u003e\u003cstrong data-end=\"3529\" data-start=\"3495\"\u003eWhy Buy from Probuild Aircraft\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp data-end=\"3723\" data-start=\"3530\"\u003e✅ Official UK stockist – 100% genuine UMS engines\u003cbr data-end=\"3582\" data-start=\"3579\"\u003e✅ Trusted by top international pilots and builders\u003cbr data-end=\"3635\" data-start=\"3632\"\u003e✅ Fast UK shipping and secure packaging\u003cbr data-end=\"3677\" data-start=\"3674\"\u003e✅ Supplying and supporting pilots since 1993\u003c\/p\u003e\n\u003cp data-end=\"3723\" data-start=\"3530\"\u003eManual:\u003c\/p\u003e\n\u003cp data-end=\"3723\" data-start=\"3530\"\u003e\u003ca rel=\"noopener\" href=\"https:\/\/ch-ignitions.com\/wp-content\/uploads\/2020\/03\/ums-gas-radial-engine-manual-9-115.pdf\" target=\"_blank\"\u003e\u003cimg height=\"351\" width=\"233\" alt=\"\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0934\/7711\/0146\/files\/Screenshot_2026-02-04_115553.png?v=1770206937\"\u003e\u003c\/a\u003e\u003c\/p\u003e","brand":"UMS Engines","offers":[{"title":"Default Title","offer_id":56341553611138,"sku":"UMS5-55","price":1550.0,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0934\/7711\/0146\/files\/UMS-5-55CC-PETROL.jpg?v=1770806103","url":"https:\/\/www.probuild-uk.co.uk\/products\/ums-5-cylinder-55cc-petrol-radial-engine-4-stroke-scale-aircraft-powerplant","provider":"Probuild Aircraft Ltd","version":"1.0","type":"link"}