Originally Posted By: SteveSRT8
Originally Posted By: G-MAN
Originally Posted By: SteveSRT8
Their 412 V8 was a Cadillac design, just tweaked and rendered in aluminum instead of iron.
The 1969 Shadow would have had the 6.2 liter engine; the 6.75 didn't come out until the 1970 model year.
That the RR V8 was based on an American design is an old and totally false rumor. The L410 V8 was developed totally in house by Rolls-Royce and was not based on any existing powerplant.
Heard it so many times and read it in print a lot as well. I can't prove it, but I will stick with it. Examined side by side the engine's blueprints were said to be virtually identical in too many ways to list. Just staring at the cutaway drawing is very revealing.
But I'm ok with whatever you like best!
Anyone who looks at the blueprints of the 1949 Cadillac V8 and the Rolls L410 and concludes they are the same design is crazy. Some notable differences: RR is a deepskirt design; Caddy isn't. RR has a gear driven cam; Caddy is chain. RR has a wet intake; Caddy is dry.
The first prototype V8 developed by Rolls in the decade of the 50s was the L380, which was a 5.2 liter, hemi-head design, and a clean-sheet powerplant. It was not based on any engine Rolls had ever produced or any engine produced by any other car company. Testing revealed all sorts of issues: lack of power, and the width of the engine, which made it almost impossible to fit in the engine bay of the then current Rolls models. The engineers went back to the drawing board and redesigned the heads and the L380N was born (N for "narrow"). The engine still did not produce that much more power versus the I6 it was to replace, so they increased the displacement to 6.2 liters, and the L410 was born.
Here's a couple of pics of the L380 Rolls-Royce Hemi that the L410 was based on. Does that look like any Cadillac V8 from the 50s?