Choosing the Correct Carburettor Size
Balance engine demand, RPM range, response and intended use.
Engine Master technical resources
The Engine Master Toolbox
Practical calculators and technical guidance to help you plan, measure and choose parts with confidence.
Check the numbers
Performance Calculators
Use these planning tools as a starting point, then confirm final component choices and measurements with your engine builder.
Calculator 01Engine Displacement
Calculate total engine capacity from bore, stroke and cylinder count.
Result—Enter your measurements above.
Calculator 02Compression Ratio
Positive piston volume means a dish or valve relief. Enter a dome as a negative number. Deck clearance is positive when the piston is below the deck and negative when it protrudes above it. This calculates static compression ratio.
Result—Accurate measurements are essential.
Calculator 03Carburettor CFM
Estimate airflow demand for a naturally aspirated four-stroke engine using displacement, maximum RPM and volumetric efficiency. This is a starting point, not an automatic carburettor recommendation.
Estimated airflow—Street combinations commonly use 80–90% VE.
Important: These calculators provide estimates for planning purposes. Always verify specifications, clearances and component compatibility before purchasing or assembly.
Learn before you assemble
Technical Guides
Read buying guide →
Choosing an Intake Manifold
Compare intake designs and choose a manifold to suit your engine combination and intended use.
Numbers are only part of the combination
Need Help Choosing the Right Parts?
Tell our team about your vehicle, engine, intended use and goals. We’ll help you work through the combination.