1uz non vvti Block differences between Series 1 and series 2

Summary

In this video, Calvin from the Catching Company in New Zealand, along with Jason, discusses the differences between Toyota's Gen 1 and Gen 2 engine blocks, specifically focusing on the 1UZ-FE engine. They highlight the changes in block casting, including the introduction of holes in the Gen 2 block for weight reduction and potential harmonic improvements. The discussion also touches on the transition from thick to thin connecting rods and the lighter pistons and crankshaft in Gen 2 engines. The hosts compare various engine components, noting similarities and differences, and speculate on the reasons behind Toyota's design choices without definitive answers, inviting viewer input and further exploration.

Takeaways

• 🔧 The main difference between a Gen 2 and a Gen 1 block is the presence of additional holes in the Gen 2 block, which makes it lighter.
• 📅 The transition from Gen 1 to Gen 2 blocks occurred around the 9th month of 1994, with the changes appearing in the USA market in 1995.
• 🏎️ The Gen 2 block was introduced alongside lighter connecting rods and pistons, enhancing engine performance.
• 🔩 The change from Gen 1 to Gen 2 is marked by the switch from thick to thin connecting rods, which is also seen in the LS400s and SC400s models.
• 🏭 The block casting for both Gen 1 and Gen 2 is believed to be the same, with modifications made for specific engine components.
• 🔧 The Gen 3 or VVT-i blocks further lightened the crankshaft by 1.5 kg and modified the oil galleries.
• 🧐 The additional holes in the Gen 2 block are speculated to be for block harmonics or windage pressure, although this is not confirmed.
• 🔍 The script suggests that the Gen 2 block is preferred by some dirt track Speedway racers due to its design.
• 📏 The block's underside has distinguishing features, such as the presence of holes, which are not found in the Gen 1 block.
• ⚙️ The script highlights the importance of matching bearing sizes when rebuilding engines, as indicated by markings on the blocks.

Q & A

What is the main difference between a Gen 1 and Gen 2 engine block in Toyota's 1UZ series?

The main difference is the presence of additional holes in the Gen 2 block, which makes it lighter.

Why did Toyota introduce changes in the engine block design from Gen 1 to Gen 2?

Toyota made changes to improve the engine's performance, specifically by introducing lighter rods and pistons.

In which year did the change from Gen 1 to Gen 2 engine blocks occur in the USA market?

The change occurred in the USA market in 1995, registered as 95 year models.

What is the significance of the additional holes in the Gen 2 engine block?

The additional holes are believed to be for either weight reduction or to change the harmonics of the block.

Is there a difference in the oiling and water holes between Gen 1 and Gen 2 engine blocks?

No, the oiling and water holes in the top of the engine blocks appear to be the same between Gen 1 and Gen 2.

What are the differences in the main cap design between Gen 1 and Gen 2 engine blocks?

The Gen 2 has chamfering and no recess, while the Gen 1 has a flat edge with recesses.

What is the purpose of the numbers found on the engine blocks?

The numbers indicate the bearing sizes fitted at the factory, which can vary and are not necessarily the same across all engine blocks.

Why might some engine blocks have different numbers indicating bearing sizes?

The different numbers could be due to mass production machining differences, where the factory adjusts the bearing sizes to meet specific tolerances.

Are there any differences in the block casting between the VVT-i and non-VVT-i versions of the 1UZ engine?

The VVT-i block casting is almost the same as the non-VVT-i, but it has modifications for the oil galleries.

What is the significance of the bolt-on drain in the engine blocks?

The bolt-on drain is an additional feature compared to the Gen 1 block and is part of the block's design for oil management.