Why Did This Rebuilt Chevrolet 235 Inline-Six Seize after 10 Miles?

The feeling of success having rebuilt a mechanical object is a high that can often only be eclipsed by the soul-crushing low of having said object self-destruct right before your eyes for seemingly no reason. It’s a real feeling felt by many a garage dweller whether they want to or not. Faced with the options of wiping your hands and walking away forever or digging in and finding out what went wrong, it’s tempting to leave. Some people are brave enough to pick up where others leave off on jobs like this though and occasionally they bring us along for the ride.

One such operation is Jim’s Automotive Machine Shop, Inc. It is a YouTube channel I enjoy watching for the informative and fun projects and banter between the father and son, Jimmie and Nicolaus, who run the place. These are the guys who pick up where the DIY folks leave off and one of the more recent engines to cross their threshold was a Chevrolet 235-cubic-inch straight-six.

This particular engine looks relatively well put together, but nothing that was well put together has catastrophic failure in the first handful of miles running down the road. This engine came with a note saying it had seized though the first thing Jim and Nicholaus do is put a pry bar on the balancer and find that it turns over by hand with minimal fight. After agreeing to a rough plan of tearing the engine down completely and then freshening up anything that needs it before reassembly the pair get to really turning the screws on disassembly.

Each step in taking something apart can tell you something if you know what you are looking for. It is fun to see what their experienced hands and eyes are looking for in real-time as the video unfolds. Yes, this is a 46-minute video but it’s worth grabbing a cold drink and learning from someone who has clearly been inside his fair share of engines as they show not only the process of disassembling this Chevy but also his personal process for inspection. What he is looking at, in what order, and how his theory on what might have happened changes with each bit of new information. It’s a process unique to each person and seeing how others do it has helped me further develop my own.

We won’t ruin the fun by completely giving away the problem that ended up being the cause, but we will give the hint that removing the valves required two hammers. There are also updates on this project in more recent videos on the Jim’s Automotive Machine Shop, Inc. YouTube channel if you are curious about how it gets fixed.

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