Engine Prototype: The Stillborn Corvair Gen2 Modular Engine – From Two to Twelve Cylinders

(first posted 6/14/2017)       A ten cylinder Corvair engine installed in a FWD ’62 Impala? How’s that to get the juices of a hard-core Corvair air-head going?

One of the highlights for me of the recent Detroit trip was the little museum in Ypsilanti, in a former Hudson dealership. It was small, but a welcome reprive from the mega-scale of the greenfield Village and HF Museum. Here we could get intimate with the displays, and there were some gems, including a few Corvairs. And there was this modular Corvair engine display, including two actual six cylinder engines and info on the program. It was mostly new to me.


Here’s the basic info. In 1961, the Corvair was still deemed to play a significant long-term role within Chevrolet, so a development program on a gen2 modular engine was undertaken. The actual Corvair had a single alloy cylinder head on each bank of individual cast-iron cylinder barrels.

The mod engine used individual cylinder-head units, cast as a single unit, eliminating the head gasket altogether. There was no info, but presumably there was a cast-iron liner in the cylinder for wear, as the Nikasil system developed for the Vega presumably was still a distant (bad) dream.

Here’s a look at one of the engines on display. The cooling shroud has been cut away on this side to clearly show the cylinders.

Here’s the other side, with its individual valve covers and log intake manifold.

The bottom of the cylinder has a large rectangular base, which is bolted to the crankcase.

The view from underneath shows that each cylinder has its own integral pushrod case, rather than the leak-prone tubes in the production Corvair engine.


The real key difference of course is that it was designed to be modular, and everything from two to twelve cylinder versions were designed, although the eight and twelve cylinder versions were not actually built.


The four cylinder version was of particular interest to Chevrolet.

It was used in FWD prototype small cars, a configuration that was of course also used by Citroen (GS) and VW in Brazil (Gol).

I showed this image at the top, but it’s worth contemplating a 10 cylinder air-cooled FWD Chevrolet Impala again. Or maybe it shouldn’t ever have been contemplated. The text said that this powertain led directly to the Olds Toronado, but it’s well known that Olds had been experimenting with FWD cars from the late 50s, and gave serious thought to building a FWD car in about 1961 or so.

The proposed engine was for a 1964 introduction, but the expense in re-tooling was obviously not justifiable. And GM was moving towards a more conventional RWD approach with its small car development program that would eventually lead to the Vega, which had a very different type of engine. But if you’ve ever wondered why the Vega did have an aluminum block, it was largely to keep GM’s Tonawanda aluminum foundry going, after a huge investment for the original Corvair engine.

What might have been…which pretty much sums up the Corvair program.