1987 Cosworth F1 GBA 1200+bhp 1.5L V-6 Engine


Here you can see two Bosch EV1 looking injectors per cylinder that actually fire upstream. I know absolutely nothing about gelled toluene so I'm not sure what benefit there was in firing the fuel upstream of the valve, but I'm sure the engineers designed it this way for a reason. At the base of the throttles you can see that they are bolted to the cylinder heads via a phenolic gasket for heat isolation. We use the same proprietary formulation of phenolic for our Subaru, Mitsu, and Nissan thermal guard gaskets today.

Here you can see the throttle castings and linkage for the individual throttle bodies. The vacuum hoses go to a vacuum/boost manifold…

…here. There are two of these manifolds: one per bank. Then a hose goes from each of the manifolds into that round device on the right. I have no idea what that round device is on the right, but it is knurled at the edge and has a huge jam nut at the base. It looks like it is for some kind of mechanical adjustment. Perhaps fuel pressure?

This is a detailed view of an inlet to one of the two plenums. The two o-rings are for some kind of Wiggins type connection I'm sure. There is considerable hand blending at the joint of the o-ring flange to the fabricated tube which is made from two pieces of sheet. I am guessing it was shaped like this to clear some kind of body work. Even to this day at Cosworth, we still spend probably too much time with attention to detail on our inlet manifolds. In the case of the Subaru EJ and Nissan VQ plenums, each port is CNC matched and then hand blended to each individual runner.

This is what the hand fabricated piece looks like from the outside. The valve cover looks like it is all business with black wrinkle coat and Ford F1 signage.

Here's a bottom view of the engine assembly. While it doesn't look quite as high tech as the current F1 CA2010 engines, it still looks like a pretty damn serious piece of machinery.

This plaque on the show engine, which also looks like it is from the 80's, states that the engine was only ever raced one season. However Robson's book says that the enigne was raced in 1986 by Carl Hass' Haas/Lola new F1 team and in 1987 by Benetton. Apparently despite the fact that the GBA was originally designed for gasoline with a 6.5:1 compression ratio and all of the other turbo engines were significantly more powerful on rocket fuel, the new Haas/Lola team couldn't produce a reliable or fast car regardless. Switching to gelled toluene, Cosworth had slowly raised the compression up to 8:1 and was producing over 1000bhp by the end of the season, but the Haas/Lola cars weren't up to the challenge. Ford decided to switch the engines to the Benetton team. In 1987 Cosworth was at the FISA 4.0bar boost limit, the engine was reliable for 600 miles between rebuilds, and the Benetton B187 was regularly finishing on the podium. But by the end of 1987 the FISA was limiting the boost to 2.5bar. The plan was to eliminate turbos from F1 by 1988 and that was the end of the GBA. No bore and stroke specs were ever officially released on this engine or any other Cosworth clean sheet race engine for that matter.

So there you have a semi in depth view of the most powerful 1980's F1 era turbo engine. There are other turbocharged CART and Champ Car engines in our conference room, but this one was always my favorite of the turbo engines. There's something about its age and simplicity that appeals to me even outside of my six cylinder fetish (all of my personal cars are 6 bangers now that I've sold off the rotaries). Perhaps it's because the Cosworth GBA engine belongs to an era that was very important to the birth of our little tuning industry today. I'm definite turbochargers in F1 made quite an impact on car manufacturers, the general public, and the Japanese tuning industry back then. The 323GTX, Supra Turbo, RX-7 Turbo, Celica All-trac, Starion ESI-R, 280ZX Turbo, SVO, XR4Ti, Cosworth Sierra, 944 Turbo, Thunderbird Coupes, etc. were all born in the 80's right after turbos came to F1. Also you can bet that HKS and Trust, pretty much the only two major players turbocharging Japanese engines back then, probably saw turbos in F1 as a source of inspiration (the Japanese love F1). If HKS and Trust didn't make the parts, our little industry probably wouldn't have been as big as it is today and we would all probably be driving and racing small block V8s today. Now that would SUCK.

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