BRONZE

#### Engine vs Engine

Comparing two different engine sizes to see witch makes a vehicle go faster.

### Hypothesis

I hypothesize that if I swap a 350 cc engine for a 454 cc engine the truck  will go faster by 2-7 km/ph. This will happen because the bigger engine is more powerful.

### Research

Engine Spec Comparison:

(Engine1) Chevy 350cc Small Block

• V8 (8 cylinders)
• 350 Cubic Inch - 5.7 Litre (cylinder volume)
• Horsepower ranges from 145 to 370
• 380 foot pounds of torque (force created by the engine)
• Fuel efficient due to low power engine
• Slow speeds and slow acceleration
• Engine used in a small car or truck

(Engine 2) Chevy 454cc Big Block

• (Engine 2) Chevy 454cc Big Block

• V8 (8 cylinders)
• 454 Cubic inch- 7.3 Litre (cylinder volume)
• Horsepower ranges from 390 to 420
• 500 foot pounds of torque (force created by the engine)
• Less fuel efficient due to higher power engine
• Faster speeds and quick acceleration
• Engine used in large trucks or high performance vehicles

**A vehicle with higher power can get to higher speeds and keep them easier, since the engine can give more work (torque) at a faster pace. The specs above show the difference between the two engines used in this experiment

### Variables

 Manipulated The Engine size Responding The Speed of truck Constant The Vehicle & recording distance

### Procedure

Step 1 - drive engine1 500 meters and record the speed

Step 2 - get engine2 ready to go in the vehicle

Step 3 - take engine1 out out of vehicle

Step 4 - connect engine2 in vehicle

Step 5 - drive engine2 500 meters and record the speed

### Observations

Hear - engine starting, ratchets turning

See - engine, truck, tools

Taste - fumes

Touch - tools, engines, truck, grease

Smell -  dirt, oil, fumes

### Analysis

For my engine vs engine science fair project my dad and I swapped a smaller engine 350cc for a bigger engine 454cc to see which one was faster. Engine1 went 60 km/hr when recorded at 500m. Engine two had a wapping speed of 83 km/hr when recorded at 500m. This change in speed happened because engine2 has more horsepower and foot pounds of torque which increases power and acceleration. Engine2 has a better performance than engine1 which I observed in the speed test.

This experiment is helpful for people to understand engines and how the size affects the speed. This could be helpful for people buying vehicles, for the people who like to race for a hobby or build cars/vehicles for fun.  Another thing to consider would be that the smaller engine will have better fuel economy as the less powerful engine requires less gas to be powered.

### Conclusion

My hypothesis was correct because engine2 went faster than engine1. The increase in speed was greater than I expected as it increased by 20 km/hr and l thought it would only go 2-7 km/hr faster. This experiment shows how bigger engines greatly increase the speed of vehicles

### Application

This experiment is helpful for people to understand engines and how the size affects the speed. This could be helpful for people buying vehicles, for the people who like to race for a hobby or build cars/vehicles for fun.  Another thing to consider would be that the smaller engine will have better fuel economy as the less powerful engine requires less gas to be powered.

### Sources Of Error

We had a few problems when swapping the engines. The push rods all bent when we were tightening them on engine2 and we had to get new push rods. Also when we were testing engine2 the trucks exhaust pipe kept falling down so we had to put chicken wire on it to keep it up. These errors did not affect the results of the speed test in the end.

### Acknowledgement

Thanks to my Dad and Grandpa for helping me on this project and teaching me all about engines and mechanics!