Jurnal Teknik Mesin Indonesia
Vol 21 No 1 (2026): April

The Influence of the crown and ring land piston dimensions on the performance of the Honda Supra X 125 motorcycle engine

Randi Febrian, Muhamad (Unknown)
Boni, Boni sena (Unknown)
Siswadi, Siswadi (Unknown)
Edlyn, Edlyn Farid Simanjuntak (Unknown)
Alwi, Alwi Azwar Anas (Unknown)



Article Info

Publish Date
03 May 2026

Abstract

This study aims to analyze the influence of piston crown and ring land dimensions on the performance of a 125 cc engine with a bore of 52.40 mm and a stroke of 57.90 mm. The research scope includes geometric dimension calculations, three-dimensional modeling using SolidWorks, and theoretical engine performance evaluation. The method employed empirical piston design ratios and performance analysis using a Brake Mean Effective Pressure (BMEP) of 900 kPa at 8,000 rpm. The results indicate a cylinder volume of 124.95 cc with piston dimensions consisting of a 4.78 mm crown thickness, 2.62 mm ring land height, 3.14 mm oil ring groove width, 36.68 mm skirt length, and 13.10 mm piston pin diameter. Performance analysis yielded a power output of 6.67 kW (8.94 HP), torque of 7.96 Nm, theoretical thermal efficiency of 59.2%, and an estimated BSFC of 75.7 g/kWh. Overall, the designed piston dimensions are consistent with the characteristics of a 125 cc four-stroke SOHC engine and approach the actual performance of the Honda Supra X 125 engine.

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Journal Info

Abbrev

jtmi

Publisher

Subject

Aerospace Engineering Automotive Engineering Control & Systems Engineering Industrial & Manufacturing Engineering Mechanical Engineering

Description

Jurnal Teknik Mesin Indonesia “JTMI” " adalah jurnal ilmiah sains dan teknologi yang diterbitkan oleh Badan Kerjasama Teknik Mesin Indonesia. JTMI meliputi bidang konversi energi, material, desain mekanikal, manufaktur dan ...