Robert Edwards
New member
Belts and chains each have their own problems. Chains stretch (by a vast amount) and if, at high rpm, a cog gets leapfrogged, then the chances are that all the valves will be bent and several pistons will be dented/holed.
Belts do not stretch, but they can break or, just as bad, slip, with similar effects. Because you can hear a rattling chain (as another poster has remarked) then an external chain tensioner is vital.
Bristol (for which read BMW; they merely nicked it) used to offer a kit to convert their 100 series 2 litre engine to gear drive. Now you're talking! Gear drive is optimum for high revs and reliability, but it is both heavy and noisy. But it is also accurate, with minimal slippage
I reckon that the trend to belt driven cams is purely a matter of cost; it is in some ways the worst of all possible worlds, in other ways the best - the temptation to delay renewal is ever-present - we might consider it as the builder passing the buck to the owner.
Belts do not stretch, but they can break or, just as bad, slip, with similar effects. Because you can hear a rattling chain (as another poster has remarked) then an external chain tensioner is vital.
Bristol (for which read BMW; they merely nicked it) used to offer a kit to convert their 100 series 2 litre engine to gear drive. Now you're talking! Gear drive is optimum for high revs and reliability, but it is both heavy and noisy. But it is also accurate, with minimal slippage
I reckon that the trend to belt driven cams is purely a matter of cost; it is in some ways the worst of all possible worlds, in other ways the best - the temptation to delay renewal is ever-present - we might consider it as the builder passing the buck to the owner.
