Car Collector Corner: Cadillac V-12 and V-16 engines

[Bruce Nunnally]

A bit cursory but a quick discussion of the Cadillac V-12 and V-16 engines:

Q: Greg, I enjoyed your article about Studebaker being the first non "Big Three" (GM-Ford-Chrysler) independent to build an overhead valve V8. I'm a Cadillac fan, and want your input as to their huge V-16 engines that were around in the 1930 era. Thanks for the interesting columns. Harry L., Baltimore, MD.

A: Read More Here

[Texas Jim]

Good read, but he had a typo about the CTS V... He called it both turbocharged and supercharged... LOL

today's turbocharged, CTS-V that puts out 556 supercharged horsepower from just 6.2-liters

[Cadillac Jim]

I tell people that seem clueless that mine is a four cylinder with an Eaton carburetor.

[airmike]

You would be amazed how many people say about my car, "oh yeah the one with the vette motor".. Maybe i should tell them its both turbo and supercharged, with an eaton carb. Then it would be as fast as yours Jim.

[Cadillac Jim]

The XLR-V and STS-V have a much more sophisticated engine with a far higher specific output, and they use a lot more smarts to get it. See Bruce's thread on the cam timing and spark maps that he runs with his STS-V tuning efforts.

The LSA has a very mild cam, timing wise, with very high lift but no VVT. With no boost, it runs like a very mild V8, such as a truck engine, and its idle exhaust note is a perfectly smooth hum, like a four cylinder or inline six, a bit loud because it must have large pipes and mufflers to let out the 556 hp when the time comes. Rating of 556 hp is a specific output of about 80 hp/l.

The XLR-V and STS-V with the LC-3 produce just over 100 hp/l (443 hp for the XLR-V) or 106.6 (469 hp for the STS-V). The higher specific output is achieved through appropriate cam designs with separate VVT curves on the intake and exhaust cams. I don't recall Bruce's exhaust note but I do expect that in a stock system it will have a smooth note like that of the LSA and that the Borla cat-back system will not introduce any of the exhaust note unevenness that we associate with old iron bow-tie V8's with dual exhaust.

I do think that you can get away with calling your LC3 a four cylinder with an Eaton carburetor too. If someone calls it a Corvette motor, nod your head and talk about 3.9 liters and three side-draft Carter carburetors and dual exhaust; this describes the 1953-1955 Corvette six (really 1953-1954, only six were sold in 1955 before the V8's queued up to the assembly line). That bad boy put out 155 hp through it's "two in the glue" Powerglide transmission.