The 1951 Chrysler 3.6 Liter V6 Hemi
Back in 1951, Chrysler engineer A.J. Rock completed work on a design study for a 3.6 liter V6 Hemi, which would have taken advantage of the high performance of the Hemi design.
In the early 1950s, straight-six and straight-eight engines were the most common, with V-8s coming into vogue — but sixes, by and large, remaining in-line.
Originally, we believed that the V6 engine shown here was an experiment; Willem Weertman wrote in his engines book that the experimental A173 was a hemispherical-head dual-overhead-cam V6, displacing 235 cubic inches, and that both Powerplant Research and Engine Design created in-line six cylinder and V8 engines with Hemi designs.
Tom Rock told us that, according to his information (including correspondence with Willem Weertman himself), it was intended for production, but someone high up at Chrysler vetoed it, saying they could not go up against the competition’s V8 engines with a V6, even if it produced more power.
It sounds like a fair statement, but Plymouth had done well against Ford’s V8 before the war — beating it in performance tests with the Plymouth Six. Plymouth would not get a V8 until late in the game, either, making the argument, if indeed it was made, ingenuous.
As for the patent number showing on the papers, it’s an internal reference (U.S. patent 489-2953 is for “benzthiazole substituted diacid terphenyl monomers”). Tom Rock told us that his father worked in department 489, so presumably it was the 2,953rd print created by the department.
A strong V-6 might have been handy for Dodge trucks, particularly the oncoming A-vans, and could have greatly helped the company’s efforts to sell vehicles in Europe and Australia. One could see European exotics adapting it, with suitable Weber carburetion, rather than the little Ford V8 or the bigger Hemi V8s.
The engine would have been a welcome replacement or supplement for the flat-head six, adding to Chrysler’s technological reputation, and probably having power comparable to smaller V-8s. It would also probably have cost more than customers were willing to pay — hence the continuation of the long-standing flathead six.
Tom Rock added, “From what information my father supplied to me, the group he was in made preliminary drawings for possible production.”