19-08-2021, 12:34 PM
(18-08-2021, 02:52 PM)Murphyv310 Wrote: Incidentally the crank and cams do not have keyways the sprockets are just held in alignment by friction.
That was the case for the 1.8 engine in my Focus, which is basically the same as the original Zetec engine that arrived in the original Mondeo back in the early 1990s. IIRC the very earliest versions of that engine did use keys, but they were removed fairly early on - I think it's quite common today. It does allow the timing to be set more accurately than relying on keyed pulleys, though I suspect it's probably only done once at the point of manufacture - I'd honestly be surprised if the garage messed with it at the cambelt changes. But I was a bit surprised when I read about it in the Haynes manual - it was the first time I'd come across it (back in 2001).
The idea of cambelts running in oil is harder to get your head around. When the 1.0L Ecoboost came out, Ford said the belt was intended to last the life of the engine. Which of course is true, as the engine's life is over when that belt fails! Their current position is that it should be changed every 10 years/150,000 miles, but as the original design was done on the assumption the belt would never need to be changed, it's a major job to get at it (8+ plus hours, £1000+ at a dealer). At this stage, I'm not planning to keep ours that long. That's not the only reason, but it's a factor... But a lovely engine to drive, and does 55mpg on a run. My previous 1.8 had less HP and torque, and hardly ever made it into the 40s - mid to low 30s was the norm. So that's impressive progress - just a shame more thought wasn't given to long-term serviceability.
