The little I know about them is they were based off of one of Buicks existing V8s (not a nail head) and used some of the same parts, like the distributor (pistons and rods too IIRC), which creates a distinctive "odd fire" sound with the position skips. Basically, they just cut off 2 cylinders from the V8. With a 225 ci V6, it must be cut from a 300 ci V8.
I held off commenting on this one because I wasn't sure if my memory was failing or not in regard to what that V6 was based off of. I
thought I remembered being told many, many years ago that it was based off of Buick's aluminum block 215. After looking into it online, I found at least one thing that supports that notion:
From WIKI:
*The first engine in this family, RPO code
6I, was introduced in 1961 for the 1962 model year
Buick Special with Buick's 198 cu in (3.2 L) engine, the first V6 in an American car (the
GMC V6 was used earlier in trucks). Because it was derived from Buick's 215 cu in (3.5 L)
aluminum V8, it has a 90° bank between cylinders and an
uneven firing pattern due to the crankshaft having only three crank pins set at 120° apart, with opposing cylinders (1-2, 3-4, and 5-6) sharing a crank pin in, as do many V8 engines. The uneven firing pattern was often perceived as roughness, leading a former American Motors executive to describe it as "rougher than a cob."
There was a later comment supporting what
@BlueC had to say:
*The bore was increased to 3.75 in (95.25 mm), and stroke increased to 3.4 in (86.4 mm), increasing displacement to 225.3 cu in (3.7 L; 3,692 cc). The engine was similar to the popular small-block Buick V8—now with a cast-iron block and displacement of 300 cu in (4.9 L), the engine was made at the same factory with much of the same tooling.
And finally...
*Dauntless
In 1965,
Kaiser-Jeep began using the Buick 225 in
Jeep CJs. It was known as the
Dauntless V6 and used a much heavier flywheel than the Buick version to damp the vibrations resulting from the engine's firing pattern. Buick sold the tooling for this engine to Kaiser in 1967, as the demand for the engine was waning steadily in an era of V8s and
muscle cars. When
American Motors (AMC) bought Jeep, the V6 was replaced with
AMC straight-6 engines, but the ownership of the V6 tooling remained with AMC.
So much more than I ever thought I'd read about the Dauntless V6, as I've just never been all that interested in them, to be honest. But as someone said, I know people have been swapping them in for years. Now, my dad decided to take a different route. He had a Ford-built war era Jeep that he swapped in a Ford flathead v8 (from a '49 Ford, if'n I recall correctly). Not exactly sure why he did it. I think he just wanted to be different. As far as I know, my kid brother in Colorado still owns that Jeep.
