Modena Fiera 18-20 Ottobre 2007 VKR K125 A : design philosophy as function of performance and reliability www.vkr-engines.com VKR K125A PERFORMANCE AND RELIABILITY Modena Fiera 18-20 Ottobre 2007 MAIN TOPICS • Engine layout • Cooling system • Lubrication system • Auxiliary components layout • Starting system and transmission www.vkr-engines.com VKR K125A CHARACTERISTICS Modena Fiera 18-20 Ottobre 2007 • Two stroke engine with 123.89 cc displacement • Bore and stroke 54 x 54.5 mm • 5 scavenging ports • Water cooled with built-in water pump • Electric starter • Counterbalancing shaft • Centrifugal dry clutch • Exhaust power-valve • Homologated fixed advance electronic ignition • Maximum working engine speeds: 14000 - 16000 RPM (imposed by limitator) • Indicated specific power 200 - 340 BHP/L • Dry weight 13 Kg Homologation: CIK-FIA 14/M/15 Homologated categories: KF4 - KF3 - KF2 - KF1 www.vkr-engines.com VKR K125A ENGINE LAYOUT Modena Fiera 18-20 Ottobre 2007 • Rear oriented cylinder with increased angle between scavenging ports and reed-valve housing • 6 petals reed-valve optimized to crankshaft configuration www.vkr-engines.com VKR K125A ENGINE LAYOUT Modena Fiera 18-20 Ottobre 2007 Engine to chassis interface aligned with main bearings and main wall structure www.vkr-engines.com VKR K125A ENGINE LAYOUT Modena Fiera 18-20 Ottobre 2007 Alignment of main bearings to main walls and engine supports 18mm dia connecting rod pin and engine main walls location www.vkr-engines.com VKR K125A COOLING SYSTEM Modena Fiera 18-20 Ottobre 2007 Split cooling system between Water pump location crankcase and cylinder www.vkr-engines.com VKR K125A COOLING SYSTEM Modena Fiera 18-20 Ottobre 2007 Water pump driving system with 0.5 Water flow control bushings on the pump/crankshaft ratio (plastic impeller) inlet of the cylinder and on the outlet of the crankcase www.vkr-engines.com VKR K125A LUBRICATION SYSTEM Modena Fiera 18-20 Ottobre 2007 • Lubrication pump obtained from water pump driving gears • Circulating oil quantity 30cc www.vkr-engines.com VKR K125A LUBRICATION SYSTEM Modena Fiera 18-20 Ottobre 2007 • Counterbalancing shaft gears lubrified on gear disengagement side • Lubrication of each bearing www.vkr-engines.com VKR K125A AUXILIARY COMPONENTS LAYOUT Modena Fiera 18-20 Ottobre 2007 Extractable counterbalancing shaft Localized high stiffness at counterbalancing shaft supports www.vkr-engines.com VKR K125A STARTING SYSTEM AND Modena Fiera 18-20 Ottobre 2007 TRANSMISSION • High power starter motor • Transmission chain on the left side of the engine www.vkr-engines.com VKR K125A FIRST RACING SEASON BALANCE: Modena Fiera 18-20 Ottobre 2007 PERFORMANCES 2007 racing activity was mainly focused on the KF3 category due to economical factors and of engine development capabilities, obtaining the following main results: • Victory at the KF3 Bridgestone Cup Swiss ( Nico Muller ) • 6th place at the CIK-FIA KF3 European Championship ( Henri Rajala ) • 6th place at the CIK-FIA KF3 Vicking Trophy ( Kalle Kulmanen ) • Pole position at the CIK-FIA KF3 Vicking Trophy pre-final ( Henri Rajala ) • 7th place at the KF3 beginning race ( Trofeo Margutti at Parma – Nico Muller ) www.vkr-engines.com VKR K125A FIRST RACING SEASON BALANCE: Modena Fiera 18-20 Ottobre 2007 RELIABILITY From a reliability point of view, we had sustained: • No withdrawals due to engine failures (6-8 drivers on a dozen main events to wich can be added numerous other participations to minor rilevant racing events) • Marginal failures of auxiliary systems external to the engine ( i.e. failure of starter gear loaded by centrifugal forces, was later found to be out-of-spec) • Constant performance throughout racing events www.vkr-engines.com VKR K125A SUMMING UP OF THE Modena Fiera 18-20 Ottobre 2007 ENGINE PECULIARITIES • Very high reliability ( we have engines that used more than 200 liters of fuel without any kind of maintenance) • Constant performance level throughout racing events (very good behaviour of cooling and lubrication systems) • Ease in wich interventions can be performed on main auxiliary components • New CIK-FIA rules interpretation fully compliant (especially applicable for the inspection of the counterbalancing shaft, wich can be done quickly and with ease) • Exceptional behaviour of the transmission chain due to the different kind of applied stresses on the rear axle (LH transmission) • Outstanding high speed performances www.vkr-engines.com VKR K125A ENGINE PRODUCTION AND Modena Fiera 18-20 Ottobre 2007 DISTRIBUTION The engine is produced and distributed by: Villa Kart Racing – Via 4 novembre 49/bis – 10019 Strambino TO Italy Tel. +39 0125 714042 Fax +39 0125 639946 E-mail: [email protected] Website: www.vkr-engines.com Imagination is more important than knowledge Knowledge is limited Imagination encircles the world Modena , 18 Ottobre 2007 – Produced by Uber Ferraguti.