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New Targa Volvo 122 takes shape
After five years that have seen three top ten classic handicap finishes in the world’s greatest tarmac rally the White/Yelds ex-works Volvo 122 is to be given a rest. April 2008 will be its last Targa before being returned to original 1960’s specs and retired for demonstration events. A new shell has been procured and work has started on preparation for a debut on the 2009 event.
Preparation for 2008.
Changes to regulations have necessitated an engine change and deficiencies in both fuel and braking systems are being addressed in readiness for Targa 2008.
Engine preparation
The current engine is a B18 block (originally 1770cc) bored to the class limit (2000cc) Under new Tarmac Rally regulations capacity is limited to original capacity + 10% (1958cc). In a move away from doing everything in house we approached Gary Comerford of Volpro Automotive to build the new engine block.
Gary has been helping with cylinder head development for a couple of years and his unrivalled expertise with these engines makes him the natural choice. After sourcing a good block Gary began work knife-edging the crank, polishing and shot-peening the rods and ordering specially built forged pistons from the USA. The crank did not pass crack testing so an alternative crank has been sourced. The new bottom end will make the engine unburstable and keep us legal. However, it won’t produce any more horsepower (112hp at back wheels last year) unless we swap to Weber carbs and/or do further cylinder head development.
Fuel system
On this year’s Targa we lost considerable time with a persistent engine misfire high up in 3rd and 4th gears. We chased the problem all week and finally, on the last day found debris in the fuel tank pick up pipe. Once fixed we rocketed from 11th to 6th in Classic over the remaining stages! Running a 40 year old tank was the source of the problem. We have now fitted a foam filled fuel cell (fits in existing space exactly) with dual pick ups, dual pumps and lines. We have achieved lower weight, lower centre of gravity and a reliable fuel supply!
Braking system
The standard 122 front brakes have been operating at their limit and beyond for a couple of years now. We have used carbon/kevlar pads, new rotors, the highest temperature brake fluid and brake scoops but we continued to lose the pedal with boiling fluid on many of the downhill mountain passes.
Pad knock-off has also been a consistent issue due to distortion of the disc at extreme temperatures. For 2008 we are utilising Nissan Skyline alloy calipers, 296mm 28mm thick commodore discs with aluminium hats.
These will achieve lighter weight, greater pad area, greater diameter, cooler running and far less distortion. Caliper brackets and alloy hats will need to be fabricated.
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New car
Shell preparation
We were fortunate to source a shell that was rust free and already prepared for paint together with a couple of cars’ worth of spares. Our plan is to build a strong shell with a modern, fully engineered, light, chrome moly steel cage welded from front to rear suspension. Weight will be almost identical to the existing car’s basic Bond cage but will add enormously to both stiffness and safety.
The new car will inherit the 1958cc motor, upgraded brake and fuel systems, 4.3:1 LSD with 140 discs from the old car (old car returns to all original motor, close ratio gearbox and 4.88:1 LSD as it left the Volvo competition department). New car will get a new close ratio box, new paint job, new electrics and should be a great basis for Targa, hill climbs and, with some quick mods, Group Nb Touring Cars.
Colour
We are toying with a brighter blue than the existing car’s ‘duck-egg’ hue and either yellow (Swedish flag) or orange (Gulf Oil period livery) race stripes. Any suggestions welcome!
Stay tuned for further news of the build. We will be completing fuel and brake systems during November when Co-driver, Ashley Yelds comes over from Washington DC for a week. Gary Comerford is working hard to have the block completed by that time – it would be good to have all major work completed before Christmas
Andrew White,
Darwin, Australia
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