This is all I have on it from an article.

The engine used metal cylinder sleeves, metal combustion chamber tops, metal piston crowns, bearings, valves & seats, and a stock 2.3L Pinto crankshaft. Darn near everything else in the engine, including the block, conrods, piston skirts, etc was fiber-reinforced plastic. The exact type of plastic escapes me at the moment. Very little metal was used outside of the crankshaft; just small/thin metal parts to shield against direct contact with combustion, and on mechanical wear surfaces.

This experimental engine was reportedly a great success, several were built and used very successfully in racing. HP & RPMs were dramatically higher than in the metal original, and it was quite smooth-running and durable and something like 1/3 the weight. This was one of my prime inspirations to build a polymer-intensive steam car engine.

The achilles heel was the cost. The engines were practically hand-built and would have been very pricey in production compared to mass-produced metal production engines. They tried but just couldn't scope out a way to mass-produce the plastic parts competitively, so Ford canned further research. When the few racing engines finally burned out, that was the end of it.

However the developers noted that in limited production, the tooling and fabrication methods actually made it easier and cheaper to build than a limited-production metal engine (with small-batch custom castings, forgings, and machine jobs) -- that is, for those with the unusual skills and knowledge needed. But virtually no engine shop would be able to handle such an exotic project, which is probably why it was never duplicated to my knowledge.

Weird stuff like fiber orientation for load transfer, resin/fiber ratios, resin wetting, layup, mold closing, bubble exclusion, mold-integrated component positioning jigs, etc are as incomprehensible as quantum physics or UFO engineering to most 20th/early21st century engine builders, trained, experienced, and focused as they are on metalworking. Some engine shops might know a surfboard builder, EAA guy, or body wizard who can whip up custom carbon/epoxy valve covers or oil pans for them, but that is about all, high-load polymer working parts get pretty freaky, and the idea is so obscure that it just never pops up in the first place. If they want exotic structural or loaded stuff, they'll go with CNC'ed alloy billet and feel pretty daring about it. The plastic engine was (and still is) just way too far ahead of its time. Pretty amazing that it was built in the mid-1980s.

It was also noted that the crankshaft could have been made of fiber-reinforced polymer with thin metal journal inserts, which would have upped rpms/hp even more and saved a bunch more weight, but they stuck with the stock metal crank because of budget & time limitations. They were really pushing the technological envelope as it was.