C20LET

CAM BELT AND CAM UP­GRADE Here’s how to re­new the tim­ing belt, ten­sioner and idlers on the C20LET and fit an XE in­let cam with a Vernier pul­ley.

Performance Vauxhall - - VAUX TECH - WORDS AND PHO­TOS Rob Hawkins

The tur­bocharged 2-litre C20LET is a rel­a­tively straight­for­ward en­gine with a twin cam head and a sin­gle tim­ing belt wrapped around two idler pul­leys and one ten­sioner. While it was orig­i­nally fit­ted to the Cava­lier and Cal­i­bra Turbo, it’s now a com­mon sight un­der the bon­net of many a mod­i­fied Nova, Corsa, Tigra and As­tra thanks to its fac­tory 204 bhp at 5600 rpm and the avail­abil­ity of nu­mer­ous tun­ing op­tions.

Whether you’re new or well-at­tuned to the C20LET, it’s worth know­ing what’s in­volved in main­tain­ing this pop­u­lar mo­tor, so we’ve teamed up with M J Mo­tors to show how to re­new the tim­ing belt, idlers, ten­sioner and

PER­FOR­MANCE VAUX­HALL wa­ter pump. This should be done ev­ery 40,000 miles and typ­i­cally takes half a day to com­plete, de­pend­ing on how much space you have in the en­gine bay. For the sake of pho­tos and to avoid lots of shots of fin­gers and thumbs, we re­moved the en­gine from a Cal­i­bra Turbo to make it eas­ier to out­line the work in­volved.

Typ­i­cal prob­lems as­so­ci­ated with re­new­ing the tim­ing belt on the C20LET start with the tim­ing belt cover. This plas­tic cover is se­cured with three 10mm bolts, which sit in 1mm studs in the front of the en­gine. Th­ese studs can shear off and the so­lu­tion when this hap­pens is drill them out, which can be tricky. Leav­ing the tim­ing belt cover off is the easy way around this, but you don’t want road dirt and de­bris wrapped around your tim­ing belt.

When chang­ing the tim­ing belt, it’s worth­while re­new­ing the wa­ter pump if you’re un­sure how old it is. This is some­times stuck in the en­gine block and will need some per­sua­sion with a long screw­driver to help re­lease it.

We’ve not only shown how to re­new the tim­ing belt, idlers, ten­sioner and wa­ter pump, but we’ve also pro­vided step-by-step in­struc­tions on one of the pop­u­lar C20LET mods – namely fit­ting the XE in­let cam with a Vernier pul­ley. The XE in­let cam has a higher lift over the stan­dard C20LET in­let cam, but has to be ac­cu­rately timed us­ing a Vernier pul­ley. A stan­dard pul­ley will fit, but the tim­ing will be wrong.

Many peo­ple chose to fit a sec­ond- Span­ners/sock­ets: Met­ric - 10, 13, 15, 17, 25 mm Allen keys - 5, 6 mm Torx - E10, E20 Torque wrench - 20-50 Nm Var­i­ous screw­drivers and a scraper Multi-pur­pose grease hand XE in­let cam, but this can some­times de­feat the point of the mod­i­fi­ca­tion, un­less you’re sure it’s in good con­di­tion. A vis­ual in­spec­tion of a sec­ond-hand cam will hope­fully spot any cracks or ex­ces­sive wear, but there has to be a sig­nif­i­cant sav­ing over brand new parts for a sec­ond-hand part to make sense. SBD Mo­tor­sport for in­stance, sell a brand-new XE in­let cam made by Kent Cams for £288 (in­clud­ing VAT) and a pair of Kent Vernier pul­leys for £229.

The fol­low­ing 20 steps show what’s in­volved in re­new­ing the tim­ing belt, idlers, ten­sioner and wa­ter pump on the C20LET and swap­ping the stan­dard in­let cam and pul­ley for an XE cam and Vernier pul­ley.

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