Presented by Centric Parts and its StopTech performance and racing division

August 24, 2012

When "Hybrid" Had a Different Meaning

Do you recognize these parts? If you do, you're probably a classic car owner or restorer - or you might work for Centric Parts. Shown above are a brake caliper and pistons, the body of the caliper being made of magnesium. It is one of the lightest calipers you'll ever likely hold, and also one of the rarest.

The caliper was sent to Centric to see if we have a seal for it. Centric Parts' tech department gets all kinds of special requests like this one. Sometimes they involve unique operation or installation challenges and sometimes they involve rare components from rare applications. No challenge is too great.

The car that these came from is an Italian bodied sports car from 1967. The heart of this exotic machine is a little less exotic but no less impressive, a thumpin' American V8 plucked from a Chevy Corvette. Besides providing more than 300 horsepower to the rear wheels, this 5.3 liter engine actually contributed something to the car's name as well.

While it might seem odd today, these Italian-American "hybrids" were somewhat common in the 1960s. There were hybrids from Iso, De Tomaso, Dual-Ghia and others, that could be bought in the U.S. With exotic Italian styling, some used Ford engines, others used Hemis and still others used Corvette motors, like our featured car.

This car was based on the Iso Rivolta 300 chassis, and was designed and built by a short-lived pairing of Italian car builders, including Giotto Bizzarrini, Giorgetto Giugiaro and Renzo Rivolta. It had a welded sheet steel tub and a fully independent double wishbone suspension in the front and a De Dion axle in the rear.

The Chevrolet V8 was chosen because it was ample in power, cheap to purchase and maintain, simple to tune and best of it all, it would run reliably all day and all night. After moderate tuning, the engine provided 365 bhp, which helped keep the car well ahead of one of its main competitors, the Ferrari 275 GTB.

Like a race-car, the interior space seemed planned as an afterthought. Both the speedo and tach were located centrally with temperature and oil pressure gauges in front of the driver. Furthermore, very little insulation was provided to stop heat and noise from reaching the occupants.

You might have guessed by now, but the car we are talking about is the Bizzarrini 5300GT Stradale. It weighed around 2,600 pounds and cost around $10,000 when new. The Corvette engine helped get it from 0-60 in 6.3 seconds, through the quarter mile in 14.6, and on to a top speed around 145 mph.

Just 115 examples of this car were built in total from 1966-1969 when the company folded. The first 25 or so were actually sold as Isos, but once the group split, Bizzarrini took over production himself and the car stayed mainly the same.

It's fun to be a part of a team that gets to work on such rare and exotic vehicles from time to time. We actually have another one we're working on right now that comes from Japan. But that story will have to wait for another time.