Holden HZ GTS Monaro

There is a view expressed by critics of late 1970s Monaros that the four-door HZ was a betrayal of model's heritage as Australia's first true muscle car - little more, in effect, than a 'tizzied' up Premier. Well, try this for a contrary take on the HZ's role in performance Holden history.

Those original HK two-doors appealed strongly to males in their mid-to late 20s with decent incomes and prospects for improving financial security. Most would have viewed the GTS they bought in 1968 as a final indulgence before the onset of domestic responsibility.

Five years later and as bassinet access became a priority there arrived the HQ sedan; V8 power now mandatory but with concessions to practicality. On to 1977 and our 30-something Monaro enthusiast seems doomed to the prospect of a sensible car with air and power steering. Premier ownership looms but then appears the HZ GTS with the best dynamics and brakes of any full-sized Holden and significant concessions of creature comfort. The Monaro, like its owners, had matured.

The factor that set HZ Monaros - and all HZ Holdens - apart from their predecessors was Radial Tuned Suspension. Holden's HQ had introduced in 1971 the brand's first all-coil suspension, with vastly improved ride quality coming at the price of mid-bend wallow and almost incurable understeer. Yet the fix was a simple mix of revised suspension geometry, a larger anti-roll bar and shock absorbers that transformed the HZ GTS into one of the better handling cars of its era.

As expected of a car facing replacement within months by the European-designed Commodore, the HZ GTS wasn't going to drain Holden's budget for anything more than a very minor facelift. The grille and quad-headlamp front were shared with the Premier while the ducktail rear spoiler was a carry over from the HX. The HZ's most distinctive feature was a front air dam that channeled cooling air to the brakes and was prone to getting crunched against concrete carpark buffers.

Missing, however, was any on-car reference to Monaro. While Holden's promotional literature still referred to the car by that name, those that actually appeared on showroom floors were identified only by GTS badges front, side and rear.

Power from the locally manufactured V8s had declined markedly since 1974 when rudimentary emission control measures were first introduced. By 1977 the 5.0-litre engine's official power output had dwindled to 161kW - down 10 per cent on the HQ's 179kW. The 4.2-litre suffered proportionally less with a six per cent drop to 130kW. A four-speed M21 transmission was standard, with the durable Turbo-Hydramatic a popular alternative.

Check seat inserts remained a feature of the HZ interior and options included air-conditioning and electric windows. From May 1978, power steering became mandatory and the 4.2-litre engine was deleted.

The HZ GTS enjoyed an unspectacular lifespan and disappeared without fanfare during the early months of 1979. Actual production figures are unknown but HZ Monaros are among the rarer performance Holdens.

Tony Augello has been a Monaro enthusiast ever since acquiring his first HZ more than 20-years ago and vowing, after selling that original car that he would always get another. That promise came to fruition 18-months ago, when came across our featured 5.0-litre.

"It needed a bit of a tidy up and had a rebuilt engine after being driven without the radiator cap but apart from that it is a very original car," Augello said. "I've been offered quite a bit more than I paid but I have no intention of letting it go."

ON THE ROAD
When discussing cars that are available only with V8 engines, the significance of the 'F word' can't be overlooked. In that respect, little has changed for Monaro buyers who during the 1970s were dealing with fuel prices that had doubled from 12 cents a litre in 1973 to 24 cents by 1979.

Based on road test figures recorded when the HZ was new, a gently driven four-speed is likely to return around 15L/100km, rising to more than 20L/100km for an automatic being used in city traffic. Choosing a 4.2 will cut consumption by around 10 per cent, with premium unleaded fuel plus regular doses of valve seat protection recommended for both engines.

Fuel consumption aside, there really are no costly downsides to HZ GTS ownership. Mechanical components are freely available and exceptionally tough, so buying a well-maintained car that hasn't travelled mega-km should ensure minimal repair and maintenance costs.

Then there is the HZ's inherent toughness that ensures its viability under conditions that can reduce more exotic models - including some locally-built muscle cars - to rattling, creaking wrecks after just weeks of frequent use on second-rate roads.

Standing-start acceleration, even with the bigger engine, doesn't deliver the same urgency as before the V8 was hastily modified to comply with more stringent emission regulations that were implemented during 1976. Jumping from 0-60km/h took almost a second longer in a 5.0-litre automatic HZ than for an HJ of similar specification but the standing 400m time increased only marginally from 16.3 to 16.8sec.

The combination of power steering and RTS played a major role in the HZ's enhanced drivability. Those who had been accustomed to earlier models' body roll and extremes of steering input were amazed at the HZ's ability to negotiate slow, tight bends with little more than half a turn of the alloy-spoked wheel.

"Radial Tuned Suspension really does make a hell of a difference," Tony Augello says of the design element that most clearly separates an HZ from preceding models.

"They are just so much tighter to drive and handle bumps really well and if you want to make them handle even better it's easy to get heavier springs and anti-roll bars."

Brakes were a further inducement to taking the scenic route rather than sticking to the freeway. In place of earlier Monaro's front disc/rear drum layout that demanded a hefty push for little retardation, the HZ's all-disc arrangement would handle harsh treatment with minimal fade.

BUYING
The cost of owning an early, two-door Monaro has increased manifestly during the past two years but frantic activity on the HK-HG sales front has impacted only marginally on four-door values.

Excellent, original 5.0-litre manual cars enjoy greatest demand and are among the more difficult Monaros to locate. Once you find a contender, the first move is to check the build plate, which should include the letters QT. Cars showing QR were originally built with 4.2-litre engines.

The latest Unique Cars Aussie Value Guide found 19 HZ Monaros on offer at an average asking price of almost $9000. That compared with 56 HQ-HX four-doors available during the same survey period and averaging around $1000 less.

Those comparative values and degrees of availability seem to have altered only marginally since late 2004; HZs with automatic transmission and in sound condition still available at less than $8000. Four-speed, 5.0-litre cars in pristine condition are likely to cost in the region of $15,000.

Contact with one of the country's very active Monaro clubs is a sensible point from which to commence your search but not the sole source of good cars, which can often be found during a trawl through Unique Cars or your local classified newspaper.

BUYER CHECK POINTS

BODY
Rust seems less of a problem with HZs than other Holdens of this series. Susceptible areas include the wheelarches, rear quarter panels, windscreen surrounds, sills and the boot floor. Check the seat mountings for rust and loose bolts and the front air dam for impact damage. Most parts are common to other HZs and we found second-hand GTS front guards on offer for $250 a pair.

ENGINE & TRANSMISSION
Holden's locally manufactured V8s have a deserved reputation for durability and well-maintained engines should cover at least 250,000km between major rebuilds. Oil leaks from the cylinder heads and rear main bearing seal are features of these engines and not an issue unless serious. Worn water pumps are a common cause of overheating but replacements are cheap. The HZ had a larger radiator than previous models but neglect can result in poor cooling. Manual gearboxes are notchy by nature but excessive gear whine or selection problems need professional investigation. The T400 automatic ranks among the best self-shifters in the business so vibration and slow gear selection - reverse should engage in less than 2sec - signify trouble.

SUSPENSION & BRAKES
Sagging coil springs can be cheaply replaced or reset to eliminate the 'crashy' ride that cars with worn springs display. Chopped-out suspension bushes and ball joints manifest in excessive negative camber and consequent tyre wear. Scored brake discs are common but so are replacement parts. Wire wheels were a factory option and if your car has these ensure the spokes are tight and the rims aren't buckled.

INTERIOR & ELECTRICAL
Replacement trim materials and even instrument panels (around $500 new) are available, so don't be discouraged if a GTS in otherwise good condition is showing signs of interior distress. If the car has air-conditioning ensure it delivers an immediate blast of cold air as compressor leaks are common. Make sure that electric windows where fitted operate smoothly. Cracked motor mountings cause shuddering as the window is raised and replacements are scarce.

FAST FACTS

PRODUCTION: 50,155 (total HZ)

BODY: all-steel, unitary construction, four-door sedan

ENGINE: 4.2 or 5.0-litre overhead valve V8 with single downdraft carburettor

POWER & TORQUE: 161kW @ 4800rpm, 400Nm @ 3100rpm (5.0 litre)

PERFORMANCE: 0-100km/h - 10.2sec 0-400m 16.8sec (5.0-litre automatic)

SUSPENSION: Front - coil springs with upper & lower control arms, anti-roll bar, telescopic shock absorbers Rear - coil springs, four-link location, anti-roll bar, telescopic shock absorbers

BRAKES: disc front/disc rear, power assisted

WHEELS/TYRES: 14 X 6 steel, ER70H14 radial

PRICE RANGE: $2000 - $15000

CLUB: Monaro Owners Clubs in all States