STEP-BY-STEP CAMSHAFT UPGRADE GUIDE
It’s often said that the complexity of modern engines means that they offer increasingly less and less scope for DIY tuning, unless you’ve got access to all the ECU mapping kit and electronic diagnostic equipment. To some extent that’s true of course, but even with newer Vauxhalls, the bolt-on tuning approach is still as simple as it was on a Chevette. And just to prove the point, here we’ll show you how to fit a pair of Cat camshafts to a 2.2-litre 16-valve Astra Coupe. In comparision with old-school engines of course, there are twice as many valves, combined with two cams instead of just the one, but if you take your time and double-check everything to do with the cam timing then it’s really not that tricky to do at home.
The cams we chose were Cat’s 4603111 ‘Sport’ application, which are a fast road design offering increased lift and duration, intended to give an 8-10 per cent improvement in power without hurting the everyday driveability of the Z22SE engine. They’re not cheap but they’re a well engineered product manufactured from billet steel. Crucially, these cams can run with the standard ECU and do not require special springs, retainers or anything else: it’s effectively a simple bolt-on job. Well, simple if you know what you’re doing, so here’s the process of what is actually involved in fitting them.