Performance Vauxhall - - FRONT PAGE - WORDS AND PHO­TOS Paul Wager

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.

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