In reading books, articles and postings on Virtual Vairs and the CorvairCenter forum about Spyder engines, I’ve learned some interesting differences from the standard engines. I’m doing this off the top of my head, so I may not have all my facts straight.
- The carburetor was a single-barrel side-draft unit with the flow-rate sized to control the boost from the turbocharger.
- The exhaust pipe path necessitated a cutout at the rear of the car for the tailpipe.
- The crankshaft is nitrided to improve strength and reliability.
- The compression ratio is lower to allow the engine to run on the pump gas that was available in the 60s.
- The distributor was controlled by a vacuum unit that retarded the timing instead of advancing it at higher vacuum (lower loads).
- The dash is special with additional gages for boost and cylinder head temperature.
- The front anti-roll bar and heavy-duty springs were standard.
- The engine was only available in a 2-dr coupe or convertible.