Timing Chain vs. Timing Belt
You have probably heard the terms "timing chain" and "timing belt" before, either in the context of vehicle maintenance or just engines in general. One is clearly a belt and one is a chain, but what that difference means isn't quite so obvious, and neither is what they do or why they're important. To help break this all down, Germain Honda of College Hills has put together this helpful guide to timing chains and belts, and everything you need to know about them.
Engine Timing Basics
Automotive internal combustion engines use a series of valves to direct the flow of spent exhaust gasses and clean intake air, thus ensuring continuous proper functioning. These valves are opened and closed by the camshaft, or camshafts, which make two complete rotations for every one complete rotation of the crankshaft. All of these rotations have to be timed precisely to one another for the engine to function, something known as "mechanical timing", and the job of keeping this all running smoothly belongs to the timing chain or belt.
Timing Belt vs Timing Chain
The older of the two methods used for mechanical timing, a timing chain both looks and operates a lot like a bicycle chain. Tensioners controlled by engine oil pressure keep the chains in place. The big advantage of the chain is that it's much more durable than a belt, and some manufacturers say they never need replacing, and will last for the life of the vehicle. The downside is that a lack of engine oil pressure can cause the tensioners to back off, and there is a potential for serious engine damage in that situation. These aren't as common in Honda engines, but some still use them.
First introduced in the 1960s, timing belts run quieter than chains, and maintain their position through tensioning pulleys, which don't require engine oil pressure to stay in place. And while they are very strong, they aren't quite as strong as chains, and do eventually wear out. Belt replacement intervals are usually between 60,000 and 100,000 miles. This is actually about the same interval as the engine's water pump, and it's usually a good idea to just replace both at the same time, thus avoiding a lot of extra work taking the front of the engine apart twice. Most modern Honda engines use belts.
What Happens If I Don't Change My Timing Belt or Chain?
Fortunately, by performing regular maintenance on your Honda, you shouldn't have to ever worry about the timing chain or belt failing. However, if that maintenance is ignored, you can have a failure, and it will likely be catastrophic.
A worn timing belt will potentially snap right in half. This is most likely to happen when starting or shutting off the engine, as these are the times when it's under the most stress. A failure will cause bent valves or valve guides, bent connecting rods, or destroyed pistons. And no matter which of these happens, it is a major repair, or sometimes even requires a total engine replacement.
A timing chain failure looks pretty much the same as one with a belt. A chain is more likely to slip off than break, but both will cause the same result. A high RPM failure in particular will be very likely to destroy your engine.
Proper Timing Belt and Timing Chain Maintenance
While a failure of one of these components is a very serious thing, it is fortunately very easy to stay on top of the maintenance of them. Should replacing these components be necessary at certain intervals, it will be a part of your normal maintenance schedule. But this is a very important part of that schedule, so if you have any questions about the required service for your vehicle, the team at Germain Honda of College Hills is here to help answer your questions and make sure your vehicle stays in good working order.