Alfa Romeo Turbo

[fred cook]

I ran across these photos of the Alfa engine to which we added a turbo. The engine was a 1750 and kept the Spica fuel injection but with a much modified space cam. This engine was in a GTV coupe. VERY fast car for the mid 70s!!!

[slow&rusty]

Very interesting...!

What size and brand of turbo and how much boost? How did you compensate for additional fuel (if any?).

What I see is a non-intercooled set-up with internal wastegate. Interesting placement of the turbo as well. Any details on that exhaust manifold?
Sweet.
Yasin

[fred cook]

Sorry, but don't remember many details. I really had not thought about this engine build until I found the pictures. What I do remember is that the shop owner bought the turbo kit and basically handed it to me and one other mechanic and said "build it". Getting the hardware mounted was the easy part, getting it to run properly was much harder. The Spica mechanical fuel injection relies on a 3 dimensional space cam to alter the amount of fuel that is put thru the injectors. By polishing and grinding on certain faces of the cam the system was finally tricked into adding more fuel when the engine was on boost. As I remember, there was no waste gate, so the boost had to be carefully regulated to keep from knocking the tops out of the pistons. Seems like we settled on about .7 - .8 bar of boost on an engine with 8.5:1 pistons. Cams were left stock. There was just a little turbo lag which quickly became gobs of power. A very good running but stock 2.0 liter Alfa would hit about 140 on the top end. This 1750 was good for about 10 - 15 mph more but would get there much more quickly because of the added torque. I don't remember there being any problems with the tranny or rear end because of the extra power. I suspect that the elastomeric donuts on the driveshaft would not last too long however.