What Cam Duration Does Everyone Use?

[cliolord]

I want to know your feelings on cam durations. What are you running and is it lumpy?

Does 276* sound good for a nice idle and decent power?

[richy]

in the williams, most ppl go for about the 260 ish degree cams, a few have used higher spec, couldnt say who tho!

for example kent rn2002 spec, although catcams seems a much better option now!

[stan]

upto and around 280deg if timed appropriately are fine.

all depends on how u set them.

if u find that maybe they are a wee bit lumnpier than you would like, back the timing off a bit.

[Andy P]

Is 260 a fairly mild cam then?

Wont reduce the low down grunt of a F7R with a set of 260s?

[Martin]

260's give more everywhere really.....pretty mild, stnd 172 cams are 260's iirc

[Andy P]

As is so mild not worth bothering with?

Had a fairly lairy cam in my old 106 which was pants, no pull at all until 5k.

That kinda put me off cammed up motors really.

There much point in camming without headwork?

[stan]

yup thats mild.

thing is to remember that when speaking of duration it tends to be measured from 0.1mm lift....a better idea is to compare this to the lift at say 1mm of lift. this indicates the ramp acceleration rate and how much lift a lobe is giving "early on"....this also affects lift at tdc and so power and delivery.

eg.

1 cam gives 280degs from 0.1mm lift, and 250degs from 1mm lift.

another gives 280deg from 0.1mm lift and 265degs from 1mm lift.

The latter will give more lift at tdc if using the same centre line seperation...lift at tdc....but both are "280deg cams".

[Andy P]

So which would you say is the best cam option then?

280 or 260?

I wouldnt like to loose the drivability of the 2.0. Which is what has helped my set a new PB of 9 months with sticking with 1 car

[stan]

it depends on the rest of the engine spec.

both are usable.

[J o n]

260 will be easier to live with and be better overall imo, 280 imo is far too wild on a standard engine.

and no, you dont need headwork to see big gains from a decent set of cams.