Comparing Cams (1ZZ)

[shnazzle]

Looking at cams, wondering what things to look out for when selecting cams

Stage 1

Crower: 264'/264', 0.379"(9.627mm)/0.367"(9.322mm)
CatCams:257'/254', 0.406"(10.3mm)/0.376"(9.55mm)

Stage 2

Crower: 272'/272', 0.396"(10.058mm)/0.396"(10.058mm)

CatCams seems to stagger the duration between intake and exhaust, so there's more overlap. So not sure what the VVTI would do with that. Would it do exactly what it does on stock lift?

Also the lift on intake for the CatCams seems to be quite aggressive

[lamcote]

It's only a small difference and they will still give max lift at the same points so I doubt it will be an issue. The standard cams have an even bigger stagger 240/224 I think?

The big thing is the lift. The catcams inlet lift is HUGE and when that's combined with its shorter duration the valve acceleration is going to be seriously quick. That's going to need some very stiff valve springs.

[shnazzle]

It's only a small difference and they will still give max lift at the same points so I doubt it will be an issue. The standard cams have an even bigger stagger 240/225 I think?

The big thing is the lift. The catcams inlet lift is HUGE and when that's combined with its shorter duration the valve acceleration is going to be seriously quick. That's going to need some very stiff valve springs.

Ah good shout. So then one might as well go for the stage 2 cams if you need stronger springs anyway.

I haven't looked at stock lift/duration.

So CatCams stg1 are just very aggressive stg1 cams.
I'm guessing that "snap" won't do your valves any favours either so you'd be well off with some stronger valves as well. Seems a bit of overkill

[lamcote]

Very fast valve acceleration with shorter duration can help a lot with the mid range power as long as the engine is capable of taking advantage of it. There is a limit to the benefits you get from valve lift, there's not usually any point in lifting more than the equivalent of c.30% of the valve diameter. Assuming catcams have had some proper development they may well fall nicely in between the crower stages 1 and 2, but I am sure they will need stiffer springs.

[m1tch]

I am thinking that the stage 1 cams are ok for stock springs and valves, stage 2 would probable need better springs at least - I am going with a full supertech upgrade on my build with stage 2 forced induction cams, revs will be limited to 7,800