Starting an engine upon assembly and installation into a vehicle is often as simple as turning the key or pressing the starter button – until it isn’t. There are a number of reasons why it wouldn’t be so simple, and one of them is depicted in this short video put together by John Edwards of Costa Mesa R&D Automotive Machine Shop in California. 

A customer dropped off the MG-TF flywheel to be balanced and Edwards installed it onto the machine to check out the situation, immediately noticing that something was awry with the ring gear’s installation. “It looks as if someone had tried to remove the ring gear, basically thought they could knock it off and didn’t, then it came in to us. We just took a hammer and a brass punch and knocked it back into place and we were done with it,” says Edwards.

As shown in the video, the face of the flywheel was perfectly flat, but the ring-gear on the flywheel had severe wobble, which will cause definite issues – not only with balancing the flywheel, but also with starter engagement.

Those familiar with the balancing process on V-style engines may be wondering why there are no bobweights attached to the crankshaft. Edwards explains, “It’s not like a V8 or V6 engine where you have pistons and rods going off the crankshaft at different angles. Flat six-cylinders, straight six-cylinders, straight-eight cylinders, five, four, three-cylinders don’t require a bobweight to balance as they are inherently balanced due to their design.”

Balancing engine parts is one of the most critical processes during new engine machining and assembly, as an out-of-balance component will cause havoc in the crankcase, even potentially ruining the brand new engine that’s been so meticulously assembled. 

Checking for potential issues like this is paramount to every assembly they perform at Costa Mesa R&D, and Edwards notes that careful measurement of each component – including the visual test – is important during the assembly process.