[Hybrid]

I know this is done as part of a tune. I know it reduces engine noise too (tapity-tapity). But does it have any bearing on engine performance apart from damage caused by it being adjusted too tight?

[Scrawny]

Yes, it does. If the valves are too loose they won't open enough which will cause an airflow restriction through the cylinder.

[JrZook]

Well too tight and the valves don't close fully, loss of performance. Mmmmmm too loose, increased tappet noise, extremely loose i don't know why you'd adjust them like that, but would result in valve opening stroke loss and hence performance losses. Id say likely hood of extreme damage would be very slim unless you are wayyy of the ballpark.

Anyone else?
Dan

[Scrawny]

You pretty nuch summed it up Dan

[shep]

a rattly tappet is a happy tappet

[royce]

the big thing is also valve opening duration, this can drop heaps so you lose power

on certain small pommie engines they reccomend first setting the tappets with a degree wheel to get the cam timing the same on all cylinders, then note down the different gap settings for future adjustments

[Damo]

JrZook wrote:

Well too tight and the valves don't close fully, loss of performance.

Won't this also burn out the valve seats?

[Hybrid]

Damo wrote:

JrZook wrote:

Well too tight and the valves don't close fully, loss of performance.

Won't this also burn out the valve seats?

Yeah that was the engine damage I was talking about. I thought I'd read too tight would burn them.

Though a degree wheel sounds fun I think it's probably slots into my "can't be farked" category. The old G16 is hardly a mini engine