Westfield World, Summer 2017
The Legend of the Vauxhall C20XE
By Craig Moffat
The legend of the C20XE can still hold its own today against modern engines. When I bought my unfinished Westfield SEi Widebody project from a neighbour in 2010 it came with a C20XE engine that he had sourced for the car. It had a receipt dated 1996 listing 30,000 miles or thereabouts.
Checks with Vauxhall revealed it was originally fitted to a 1993 Cavalier SRI so confirmed the low miles having run for three years in its original partner. I stuck with the engine and put it in the car. It had sat on a pallet in his front room from 1996 to 2012 when it ran in my Westy for the first time.
Originally on MBE management and Weber 45’s in 2016 I swapped that for a full Omex throttle body kit which produced 178bhp. At the turn of last year, I decided I wanted more bhp but maintaining reliability. I did contemplate changing the engine for a more modern unit of some kind. However, being interested in classic and retro cars as well, I decided to stick with the retro engine and turned to SBD Motorsport for advice.
They supplied details and a list of parts to break the 200bhp mark I was aiming for; but suggested 210bhp is where I would probably end up with the spec.
I had never worked on an engine before and had only ever stripped an old Ford 1.1 litre 8v previously to see what was inside. I gave the block, crank and head to a local engineering place who found light corrosion of the bores, probably from moisture while sitting for all those years, but no damage at all to the crank or the head.
Lauren, my wife, was not best pleased when she found out I had stripped and cleaned the head on the living room table, but where else to tackle such a job you would be inclined to ask? (Well, you’re a braver man than me, Craig — Ed)
The block was re-bored to 86.5mm and the new Omega forged pistons fitted before I took it back from them and embarked on putting it back together with new bearings, keeping standard rods documents good to 250bhp, ARP bolts and SBD’s in-house developed cams, made for them by Kent Cams. Both higher lift and longer duration with duration on exhaust and inlet being different to each other.
Having never welded before, I borrowed a big gas welder from a friend and set about mocking up the new bonnet exit exhaust manifold link pipes. Having managed to get the main part from eBay, I have to make it match my side pipe, 4-2-1, 1 3/4“ to 2” to 2.5” to give better flow. All back together with Vernier pulleys for accurate timing and billet flywheel weighing 4kg instead of 9kg.
All went smoothly until; yep, within two miniates of start-up, a leaking rear crank shaft seal meant it all had to come out again. Another seal was overnighted which meant a quick change to get it back in the car.
Second time lucky it started with no leaks while, with trepidation, I carried out the cam pun-in procedure from cold start. Then to SOS Motorsport in Falkirk where light load mapping meant I could run the engine in on the road. Doing 300 or so miles in two weeks in February/March this year meant I done more miles in that time than I did all of last year.
Back to the rolling read early in May with the engine really put through its paces for approximately three hours. The final result was 220bhp and 187lbft torque surpassing my 200 goal and SBD’s estimate of 210.
With reliable power right through the rev range and peak power from 3500-7500rpm, while maintaining a smooth 1200 idle and driveability from cold start, I am really happy with the end result.
With the light flywheel and 4-paddle clutch and instant power on tap, I have to be careful and not spin the tyres even in the dry.
So, will I tackle another engine in future? Never say never; but I think probably not. The fear of something going bang and the anxiety of watching it at high revs on the rolling may be too much to stomach again given the investment but I’m glad I have kept the old C20XE going, maintaining performance Westfield heritage with this as the XE sees its 30th anniversary.
Feature reproduced with permission from Westfield World