| Hart 415T | |
|---|---|
 Hart 415T in aLola THL1 | |
| Overview | |
| Manufacturer |  Hart |
| Production | 1981–1985 |
| Layout | |
| Configuration | L4 |
| Displacement | 1.5 L (1,496 cc) |
| Cylinder bore | 88 mm (3.5 in) |
| Piston stroke | 61.55 mm (2.4 in) |
| Valvetrain | 16-valve,DOHC, four-valves per cylinder |
| Compression ratio | 6.7:1 |
| Combustion | |
| Turbocharger | KKK (laterHolset) |
| Fuel system | Direct fuel injection |
| Fuel type | Gasoline |
| Cooling system | Water-cooled |
| Output | |
| Power output | 540–750 hp (403–559 kW; 547–760 PS)[1] |
| Torque output | 380–480 lb⋅ft (515–651 N⋅m)[2] |
| Dimensions | |
| Dry weight | 140 kg (310 lb) |
TheHart 415T is afour-stroke, 1.5-litre,turbocharged,inline four-cylinderracingInternal combustion engine, designed, developed and tuned byBrian Hart ofHart Racing Engines, for use inFormula One racing and competition, between1981 and1986.
The Hart 415T turbo initially developed about 540 hp (400 kW) in 1981, but power levels later surged, eventually going on to produce about 750 hp (560 kW) in qualifying trim and on maximum boost pressure, in 1985. The engines were used byToleman,RAM,Spirit, andHaas Lola.[3][4][5]
1980 World Drivers' ChampionAlan Jones once described the Hart turbo as a "Formula 2 engine that someone put a turbo on and said lets go do Formula One". For all intents and purposes, the Hart turbo punched above its weight in F1 with Brian Hart having a limited budget compared to the resources ofBMW,Ferrari,Honda,Porsche who built theTAG turbo engine,Alfa Romeo, orFord and their British engineering partnerCosworth.
The engine achieved three F1 podiums, all for then rookie driverAyrton Senna ofBrazil in1984. He finished 2nd at the rain shortenedMonaco Grand Prix], and followed up with third place finishes in theBritish Grand Prix atBrands Hatch and the final race of the 1984 season, thePortuguese Grand Prix atEstoril where he had qualified in 3rd place only 0.233 seconds off the pole set by his countrymanNelson Piquet in hisBrabham and its BMW 4 cylinder turboengine which was far more powerful (up to 900 hp (670 kW) by the end of 1984 compared to the 600 hp (450 kW) Hart). To that time it was Senna's, Toleman's and the Hart 415T engine's highest ever qualifying position.
The only pole position for the 415T was taken in by Toleman'sTeo Fabi at the1985 German Grand Prix at theNürburgring. Fabi had driven hisToleman TG185 to be a surprise fastest on the first day of qualifying, though he wasn't expected to stay there after final qualifying. However, the Saturday saw qualifying held in wet conditions and as such Friday's times stood for the grid with Fabi's Hart powered Toleman on pole position.
While the Hart engine had taken a great leap forward in outright power between 1984 and 1985, now being rated at approximately 750 hp (560 kW) for qualifying, by 1985 this still lacked compared to the 4 cylinder BMW (1,100 hp (820 kW)) and theV6 engines of,Renault (1,150 hp (860 kW)),Ferrari andHonda (both rated at 1,000 hp (750 kW)) and the 1984 and 1985 Drivers' and Constructors' Championship winning TAG-Porsche (900 hp (670 kW)).
The last F1 entry for the Hart engine was at the1986 San Marino Grand Prix wherePatrick Tambay qualified hisLola in a credible 11th place at theImola Circuit. However he would retire from the race after just 5 laps with a blown engine. TheHaas Lola team had debuted the newCosworth designed and developedFordV6 turbo in theirother car for Alan Jones in San Marino and from the next race inMonaco, Tambay would also drive the Ford powered car and the Hart 415T was quietly retired.
The horsepower figures for the Hart 415T turbo engine were quoted as follows:[6]
By 1986, theBMW 4 cylinder turbo powering theBenetton team (née Toleman) was quoted as producing as much as 1,400 bhp (1,044 kW; 1,419 PS), almost twice as much as the under-funded Hart unit.
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