Ep 54. Rod Ratio Examined

Engine Masters is a car show that features a team of expert builders and mechanics pushing engines to their limits in order to discover what modifications and upgrades yield the most horsepower and torque. In the season 5 episode 54, titled "Rod Ratio Examined", the team takes a closer look at the impact of rod ratios on engine performance.

The episode begins with a brief explanation of rod ratios and how they affect an engine's power output. Essentially, the rod ratio is the ratio between the length of the connecting rod and the crankshaft stroke. A higher rod ratio can increase power by allowing more efficient combustion, while a lower rod ratio can improve the engine's ability to rev to higher RPMs. However, finding the optimal rod ratio for a given engine is a complex process that involves balancing several factors.

To explore these factors and better understand the impact of rod ratios, the team conducts a series of tests on two engines with different rod ratios. The first engine is equipped with a 1.5:1 rod ratio, while the second engine has a 1.75:1 rod ratio. Both engines are otherwise identical, with the same displacement, compression ratio, and camshaft.

The team begins by testing the engines on a dyno, measuring their horsepower and torque output at various RPMs. The results show that the engine with the higher rod ratio produces more power throughout the RPM range. However, this isn't necessarily a surprise, as the team expected the higher rod ratio to have an advantage in terms of power output.

Next, the team disassembles both engines and takes a closer look at the components. They inspect the pistons, connecting rods, and crankshafts, looking for any signs of wear or damage. They also measure the clearance between the rod and main bearings, as well as other critical dimensions.

With this information, the team begins to make modifications to the engines. They swap out the connecting rods and pistons, trying different combinations to see how they affect the engine's performance. They also make changes to the bearing clearances and other dimensions, always striving to find the optimal balance of components and settings.

Throughout the episode, the team offers plenty of technical insights and advice for anyone looking to build or modify an engine. They discuss the pros and cons of different connecting rod materials and designs, as well as the importance of bearing clearance and other factors.

Towards the end of the episode, the team reassembles both engines and returns them to the dyno for further testing. The results confirm that the engine with the higher rod ratio still produces more power overall, but the team notes that the differences between the two engines have narrowed considerably.

Overall, "Rod Ratio Examined" is a fascinating and educational episode that delves into the intricate details of engine building. While some of the technical jargon may be intimidating for casual viewers, the team does a great job of explaining concepts in plain English and making the information accessible to anyone with a basic understanding of engines. Whether you're a seasoned mechanic or just a fan of the show, this episode is sure to leave you with a greater appreciation for the complex science behind engine performance.