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Performance Tuning, November 1989

You can fit a Rover V8 into almost anything it seems but when UVA were asked to do it to a Jensen-Healey the end result looked as though the car was built with someone's V8 engine in mind

If you want an absolutely unique vehicle it makes sense to go to the Unique Vehicle and Accessory Co., better known as UVA.

In this case we're pretty certain that this particular car is unique, the only Jensen-Healey with a Rover V8 under its substantial bonnet.

It's possible, probable in fact, that no other engine has appeared in so many different cars - the number of production cars it's powered is impressive enough with various different Rovers, Land and Range Rovers, MGB GT V8s and TR8s not to mention the American cars that went before Rover acquired (and modified) the unit. On top of that can be added all the conversions, such as the Stag, the kits and specialist cars, such as UVA's own. UVA in fact have themselves put that engine in all sorts of unlikely places. In the engine bay of a Capri or Sierra seems reasonable enough, but in a Renault Fuego? Well, why not, after all their VW Transporter conversion is almost commonplace by their standards. So when someone approached UVA to convert the Jensen-Healey they were quite happy to go ahead with the project, enjoying the challenge and the chance to do something different.

It helps to know what you are converting from before considering how the conversion was done, and the merits of it. The Jensen-Healey story is going back a bit now of course; we remember it well enough here but then we go back a bit too and the 1972 Geneva Show where the car was launched seems like only yesterday...

When the unlikely named Kjell Qvale, a major importer of British sports cars into the United States, saw that the end of Austin Healey production might prove a problem to his business he did something about it and something pretty drastic too. Qvale bought a majority share in Jensen who were hardly in the best of financial conditions, and revamped the upper management. Donald and Geoffrey Healey were appointed to the board and Donald made chairman. That gives a clear clue to what Qvale was after - the car that Donald Healey already had on the stocks, a sports car with all the traditional British appeal yet one without the equally traditional drawbacks of simplicity which meant crudeness rather than reliability as it should have done. History went on to prove that the answer was not the Jensen-Healey but the theory seemed sound enough. Curiously the next British sports car that was designed deliberately simple to succeed in North America, our old friend the TR7, was almost as big a flop.

The design, by the Healeys, was stylish enough and actually quite attractive, a good blend of old and new which doesn't look terribly dated even now. The mechanical parts were sourced from Vauxhall - what could be more sensible than using GM parts? They were simple, reliable, plentiful and available at the right price; Healey was just using his previous approach with the Sprite and the l00s and 3000s but just using Vauxhall rather than Austin parts as he and Austin had reached the parting of the ways. A live rear axle was chosen to overcome problems of U/J wear and unreliability associated with some independent rear systems. It wouldn't be a problem in the USA either because very few American cars, with a few exceptions such as the Corvette, had independent rear suspension. The axle was well enough located with twin lower trailing arms and angled upper radius arms. Front suspension came from the Vauxhall Viva which meant a form of unequal-length wishbones.

Originally the engine was to have been from Vauxhall too, which would have guaranteed the reliability sought. Healey had his eyes on the 2.3 litre overhead-cam slant four and that was what was used in the prototype. This is where Lotus came on the scene; Chapman had taken the 2.3's block and used it as the foundation for his new twin-cam slant-four 16-valve engine. Both from a marketing standpoint and the performance it would offer the Lotus engine had great appeal. The problem was that the design was nothing like properly sorted when Jensen got hold of it and the company, along with its long suffering customers, ended up having to do much of Lotus's development work for them out in the real world. The Jensen management surely have seen that such an unknown quantity might have teething problems but they didn't anticipate them to be quite so bad and were doubtless swayed by the fact that the engine was very good from the point of view of emissions and a good 'clean' engine was just what was required for the car's intended major market.

The 16-valve slant-four was mated to the four-speed transmission used in the faster, H120, version of the Sunbeam Rapier and was no problem. Brakes were what was found on the ends of the Vauxhall suspension units used and they had to deal with some quite lively performance. The top speed was a fraction over 120mph and the 0-60mph time of 7.9secs with a standing quarter mile capability of 16.2secs was perfectly reasonable for such a car. It was better than reasonable, it was miles better than the MGB which was such a favourite in the States and it could hold its own with the powerful if crude Triumph TR6. But then the Lotus engine did crank out almost as much from its 1973cc twin-cam as the Triumph's injected straight six, at l40bhp at 6500rpm, along with 130lb ft.

The Jensen-Healey's career never really took off, for a variety of reasons. Expensive and annoying problems with the engine were only part of it, the cabin was a total mish-mash of switches, dials and styles and it looked cheap, clumsy and unappealing even in the early '70s. And although the car's lines were unarguably very attractive the fit and finish was dreadful and rust soon became a problem.

Improvements were made during the course of production which lasted up to 1976 and the most notable of these were the introduction of the ill-fated hardtop GT version, and, in 1974, the switch to the Getrag gearbox which offered five speeds rather than the four of the Rapier unit.

It was a Getrag unit used in the car that UVA were given to modify and that was discarded along with the Lotus engine itself - actually sold rather than discarded as both were in good condition, teething problems long since overcome.

The Lotus engine being a slant-four, obviously a completely different engine mount arrangement was called for.

Conventional Rover V8 rubber mounts were used, unlike in the TR8 conversion for example which for some reason or another not terribly clear uses the different shape rubber blocks from the Triumph Stag - the ones that look like grown-up Spitfire mounts. The brackets on the engine itself, however, had to be specially fabricated. The one on the driver's side was further complicated by the need to clear the steering column - which it does by just the required bare minimum.

Some chassis members required slight modification. The round mounts shown here are standard Rover items but they required new holes to be drilled to fit. The radiator mounting bracket was altered to lower the rad.

Opening the Jensen-Healey's very large bonnet reveals an installation which appears almost factory perfect. If we thought the V8 went into the Triumph as though they were made for each other (as indeed they were) the V8 in the Jensen looks even more at home. No great modification is needed to have the engine sitting well down in the engine bay and, to show how much height there is to spare, the tall oil-filler extension and breather on the rocker boxes can be retained. Perhaps even more impressive than that though is just how far back the engine is mounted; it's actually all behind the axle line as you can tell by seeing the position of the steering rack. The benefits of this are enormous; it produces a good weight distribution and also provides lots of space between engine and radiator. UVA have done the usual trick of discarding the long-nose water pump in favour of the shorter variety found on the earlier 3500S. That's possible because there is no power steering on the Jensen-Healey so the Rover's pump can be discarded and the single pulley used on the crank. UVA use one of their own alternator remounting kits to switch the alternator from the driver's side across the engine and that in turn means there's all sorts of room around the oil filter so changing that must be simplicity itself.

The radiator was dropped down an inch or so by altering its lower mount and that means more of it is in the airflow; to assist that cooling air's passage an effective if unobtrusive scoop has been added to the front. That, and a thermostatically controlled electric fan, is enough to keep the temperature stable even on the very warm day we drove it. The Jensen-Healey has no bonnet louvres to help the heat escape - the hot air exits each side of the bonnet at the windscreen end and in any case there's a good deal of room around the engine.

The Rover gearbox finds itself a couple of inches further back than the Getrag unit and the modification that required was fairly straightforward. New holes were drilled in the chassis legs to take the Rover gearbox cross member which had only to be slightly modified. Moving the 'box back that far did, however, mean that a new hole had to be cut in the top of the transmission tunnel to allow the gearlever through. Gearlevers don't work very well without a clutch and that was rather more of a problem that you might think because the Jensen-Healey had a cable operated clutch and the Rover's is, of course, hydraulic. UVA's Alan Arnold described making up a suitable clutch master cylinder system as the trickiest part of the conversion. UVA do hydraulic clutch systems for kit cars and it was one of those that was tailored to suit and the new reservoir can be seen on top of the rear bulkhead.

Every conversion dictates a different exhaust system and this one was no exception. Even though UVA make tubular manifolds for the Rover V8 in other applications this one needed to be different - where you might expect to see the tubular manifolds sweep back the four branches are joined in the centre, almost like the old cast manifolds from the 3500S. Alan Arnold being a firm believer that twin exhaust systems on V8s are noisy, the arrangement he designed for the Jensen-Healey features a single small centre expansion box and a large silencer.

That's just about it on the conversion front as UVA had a little good fortune to make up for the frustrating aspects such as having to change from cable to hydraulic clutch, things like finding a propshaft that was the right length in the form of that from a 3500 SD1 automatic. Another stroke of good fortune lay in the fact that the Jensen-Healey's original Lotus engine was fed by an electric fuel pump and that was considered adequate to satisfy the V8's thirst.

As for the engine itself, not an enormous amount was done to it in tuning terms. It was, of course, totally stripped and rebuilt and given a slightly more radical cam. The standard SUs were removed and a four-barrel Holley fitted and that was about that.

In the course of the conversion UVA came across various other things that needed fixing, as is almost inevitable with a car of that age; for example they replaced the bushes in the radius rod which forms the front arm of the lower wishbone and fitted some uprated front brakes, while adjustable Spax dampers are used all round.

When we drove the car there were still things that could have benefited from UVA's touch, the steering rack for example was clearly past its prime, stiff and giving a very dead feel to the steering but UVA had been asked to do the conversion rather than rebuild the whole car so it's a little unfair to criticise all such aspects. Looking past the various little problems with the car it was clear that this is one of the most successful conversions you are ever likely to come across. The weight distribution is hard to fault with the heavy Rover gearbox further back than the Getrag and the V8 itself all behind the front axle line. There's bags of room all round the engine; there are no cooling problems and the engine sits low down in the engine compartment. Positioning the gearlever that couple of inches further back actually brings it to a far more natural and convenient positions.

But what about performance? Well, with l40bhp of Lotus twin-cam the original Jensen-Healey was no slouch but the Rover engine changes the whole nature of the car, giving it far more effortless performance. We didn't take any performance figures on the new engine but the most marked improvements are bound to be in the in-gear acceleration figures in the higher gears. There was some engine hesitation of 2000rpm and again past 4000rpm but this was put down to the fuel pump capacity rather than anything more serious.

Not surprisingly the Jensen-Healey now feels rather old fashioned without the grip or balance of modern machinery but had it been properly sorted from the very beginning it could have been a success with reliability to go with its undoubted comfort (a surprise to us) speed and style.

It still seems a little odd to have gone this route but the actual conversion itself works very well indeed. tures and the Rover engine does offer absolutely enormous scope for further tuning; pushing its output to beyond 200bhp is no problem and that would make this Jensen-Healey the fastest one in existence. Once all the other mechanised parts are fully sorted we would love to have another go...

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