Cam wear & bent valves

[ESDavey]

While at Brands, my mate bent a valve which resulted in a £2k+ bill inc replacing the cam which was very worn. The engine has only done 19k and the car is a 2006.

Q1 : is it normal for an Elise to suffer from valve bounce & bend valves ? I though your cars had limiters etc to stop this.

Q2 : is cam wear typical ?

Obviously being the proud owner of a V8 I dont even think about such screaming engine problems ... and I only need 1 cam !!

[Cuzza]

Sounds more like a fluffed gear change or down-shifting too early and over-revving the engine, no limiter will prevent that and the amount of damage is down to luck (or lack of it).

£2k seems steep unless it was a main dealer though.

[OJ]

I'd tend to agree with the assessment of buzzing the engine. Although if the cam was worn, rather than simply damaged by the valve cap then I'd put forward that possibly the valve guide might have seized

[Gooby]

which engine?

[ESDavey]

Toyota I believe

[Gooby]

Cam wear is not common but damage due to buzzing is. It is normally on the bottom end. Never heard of the top end going.

How many miles has the engine done?

[ESDavey]

19,000 miles. I think he was going along the bottom straight at Brands & just revved on the limiter for too long !!

[bordseye]

ESDavey said:

19,000 miles. I think he was going along the bottom straight at Brands & just revved on the limiter for too long !!

FWIW, Lotus told me before I bought my car that the max continuous was 8000rpm and the max transient was 8500 rpm. Isnt the limiter 8500rpm? If so, the full length of the straight would not be "transient" in my book.

[Gooby]

ESDavey said:

19,000 miles. I think he was going along the bottom straight at Brands & just revved on the limiter for too long !!

Bouncing off the limiter would damage the clutch springs. The damage you are specifying would mean some sort of failure on the timing chain. The engine is interference.

[kevin ritson]

There are a few issues of premature cam wear surfacing - just the other week on SELOC there was a tech post and this was followed by a link to one of the US forums where this has been reported several times. Hope your friend's problem gets sorted.