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

The compressor wheel has 12 blades and the inducer measures approximately 55mm. The shaft play tells me it's a journal bearing turbo, but the shaft play is definitely smaller than a standard T04 unit. The wheel to housing clearance is also extremely tight compared to a standard T04. In fact it appears to be closer than even at modern day ball bearing GT, but I am definite ball bearing turbo technology did not exist back then…or did it? The center housing does not look standard issue Garrett so I'm guessing there was some voodoo big money magic going on here to maximize compressor efficiency to the very extreme.

The turbine wheel is an 11 bladed deal and from the exducer doesn't look like anything too special. In fact it looks a lot like a Navistar TA34 wheel (you Turbonetics lingo people might call it a “stage 2”) if you ask me, but I did not take the turbo apart to examine the turbine wheel's blade shape. Once again the wheel to housing clearance is looking tighter than a modern day GT so I'm guessing they were trying to squeeze every last ounce of efficiency out of the turbine stage also. The turbine housing outlet is very nice with a smoothly expanding inside diameter all the way to the back of the outlet.

A v-band turbine housing from back in 1985 beats HKS and TiAL by about 21 years. From the rear view, the compressor housing uses a T04E type clamp. The turbine housing A/R appears to be extremely small. I would estimate it to be in the .40-.50 range. After all it is a twin turbo 1.5L engine with 0.75L feeding each turbine stage. It is an extremely thin wall casting so it looks smaller than it actually is I'm sure.

The turbine housing inlet and wastegate connection is hand fabricated and is welded to the exotic looking material cast turbine housing. I am unsure of the header material, but I'm guessing they are made of inconel.

Here is the bespoke multi-stage dry sump oil pump. It just looks expensive.

On the other side of the engine is the bespoke water pump at the front of the engine and the bespoke Magneti Marelli alternator behind it. The alternator looks a lot like a small version of a mid 80's European car alternator doesn't it?


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