Re: Two cams or one?

["Sean Murphy" <scm1@xxxxxxxxx>]

Hi,

I saw you question on the digest and thought I would give you my
opinion/answer.
The reason that two cams are better than one is that for *optimum*
performance, the inlet valve timing is not the same as for the exhaust valve
timing e.g amount of valve lift, duration, scavenging et. When you only have
one cam, both the inlet and exhaust valves are driven off one cam-lobe
therefore the timing, duration etc is the same for both. With two cams, one
driving the inlet valves and one driving the exhaust, you can have different
cam profiles = more power. Adding VANOS to a twin-cam set-up should give
even better performance as combustion dynamics vary according to engine load
and speed.

I hope this is of some use.
Regards

Sean

P.S An example of a single cam multi-valve engine would be the Triumph
Dolomite Sprint 16Valve.

http://homepages.tcp.co.uk/~scm1/bmw.htm

'93 E36 325i SE (24v Vanos)

http://homepages.tcp.co.uk/~scm1/bmw.htm

'93 E36 325i SE (24v Vanos)

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