Since timing chains are less prone to breakage than timing belts, why aren't more cars fitted with chains?

Answer 1

The change over from timing chains to belts occurred because the camshaft, which was driven by the chain used to be just above the the crankshaft where the timing chain was less than 20 inches in diameter. The newer, smaller engines have the camshaft at the top of the engine requiring the chain to be several feet long. With this distance, the chain would tend to flop around causing excessive noise, not to mention excessive wear on the parts they hit and excessive stretch as well. I have seen an 18 inch chain stretch to the point it was ready to jump off its teeth. To keep the engine quieter and no chance of a rogue chain whipping through the casing, they switched to a rubber belt.

Answer 2

OHC timing belt systems are much cheaper design-wise. The belts, tensioners, pulleys, etc are cheaper, simpler and take up less space than a chain-driven OHC engine.

Timing chain systems for OHV pushrod engines are cheap, and have been used since the '50s on V6 and V8 engines. But once you put the cams on top of the engine (OHC), the drive system becomes more complex. The belt systems are a good compromise, and the only tradeoff is they must be serviced every few years.

Answer 3

timing belts are cheaper to make and cheaper to mantain than a chain plus with the dual overhead cams routing of a chain would be alot more difficult plus belts are lighter and cause less drag on the engine meaning more power and better fuel efficiency

Answer 4

Because on V6 or V8 engines the engine is shaped like a V and needs more belt . If you put a chain on a V6 or V8 engine it would be a giant mess of chains. Manufacturers put chains on a 4 cylinder engine because it is one loop.

Answer 5

Don't worry they will both be gone soon enough.
Camshafts will be eliminated in automobile engines.

Answer 6

you answered your answer.the belts don't last. so dealers make more money.