To develop a Simulink model for assessing the performance, combustion, and emission characteristics of a spark-ignition (SI) engine using a gasoline-biogas dual fuel strategy, I have outlined the necessary components and the corresponding useful Simulink blocks. 
Key Components of the Model: 
- Engine Model 
- Fuel System 
- Ignition System 
- Exhaust System 
- Control System 
- Performance Metrics 
- Torque and Power Output 
- Fuel Efficiency 
Suggested Simulink Blocks 
- Signal Builder: For input signals like throttle position and engine speed. 
- MATLAB Function: For custom calculations and logic. 
- Integrator: To model dynamics and state changes. 
- Gain: For scaling signals. 
- Lookup Table: To model non-linear relationships like fuel maps. 
- Sum: For adding or subtracting signals. 
- Product: For multiplying signals. 
- Scope: For visualizing outputs like torque, power, and emissions. 
- Subsystem: To organize and encapsulate parts of the model. 
For more information kindly refer following MathWorks documentation. 
I hope this will be helpful.