The DeLorean name is one of the most famous — and infamous — in the automotive world. DeLorean is so associated with his movie star car and his trial for cocaine trafficking that it's easy to forget what a remarkable engineer he was. Until you see something like these long-hidden sketches. Then it all makes sense.
These notes and sketches, written in DeLorean's own hand, were acquired by Sam Hill of the DeLoreanWiki, and Hill has agreed to let us publish them exclusively here on Jalopnik. They had previously been in the hands of DeLorean's patent lawyer. Jalopnik has confirmed, through another respected DeLorean authority, that the handwriting does in fact appear to be DeLorean's own, and we are confident because of the source that these documents are likely genuine.
It's not exactly known what the eventual plans are for this engine, or if it was even being considered as a replacement for the PRV V6 that ended up powering the DMC-12. There's no real way to know how powerful an engine this would have been, or even what sort of size.
What is very clear is that these documents describe a highly unorthodox engine, one that seems to employ every possible alternative engine-design idea available. The engine described seems exciting, innovative, and downright radical. It does seem to borrow ideas that have been present in other similar engines, but the sheer ambition and scope of the engine as described would seem to place it in a category of its own.
In a letter to his lawyer (enclosed here) DeLorean suggests that he'd been working on parts of this design as far back as 1954, when he was working for Packard, but most of the engine's design was started in 1979. The drawings shown here are mostly from late 1980.
After reviewing the available notes and drawings, here is the best summary of the engine I can give:
Fundamentally, it's what's known as an axial engine (sometimes called a barrel engine), using a swashplate instead of a crankshaft. A swashplate translates the reciprocating motion of a piston in a cylinder into rotational motion via connecting the pistons to an angled disc on a central shaft.
DeLorean's proposed engine would have used three cylinders, arranged in a triangular formation, and in each of those cylinders it looks like DeLorean was planning to have a double-ended piston, allowing for two combustion chambers per cylinder, making it a 6-piston engine, using three cylinders.
The nature of a swash plate type of engine allows, via altering the swash plate angle, among other methods, the ability to dynamically adjust the size of the combustion chamber, a key component of this engine.
The engine was to use Aspin-type rotary valves, though it also seems that sleeve valves would be employed as well. The engine was turbocharged, with the turbocharger mounted in the center, axially on the engine, between the three cylinders.
In keeping with the unorthodox nature of the engine, it was to be air cooled via cooling channels cast into the block, much like the early Honda 1300, which was known for its remarkable air-cooled design that seemed to be derived from water-cooled designs. Air was also to be employed as a sort of lubricant and bushing material, with pressurized air bearings used extensively throughout the design. There are also notes that suggest exploring using coolant for lubrication, and vice versa.
Using lubricants as coolants isn't unheard of — most air-cooled engines use their oil for some degree of cooling — but coolant as lubricant is very unusual.
The notes also suggest that the engine could be diesel or gas or even "powdered coal" and in situations other than diesel, the preferred method of combustion would have been a laser instead of a conventional spark plug. Because of course it is.
Even the fundamental materials are radical, with a ceramic block specified throughout the notes. More conventional iron versions are suggested to be built first, but if you're going to go this far with an engine, may as well make it ceramic.
Perhaps the most truly prescient trait of the engine is one that is now actually becoming quite common, albeit in a somewhat different execution: regenerative braking/KERS. DeLorean's engine is not a hybrid design at all, it's entirely a combustion engine, but the designs still describe a way to recover the kinetic energy lost (usually to heat) during braking.
DeLorean's recovery system sounds familiar to an early flywheel-based KERS system at first, in that it uses a flywheel. But then it repurposes that energy in a very unusual way. Here's what DeLorean said about it in a December 29, 1980 letter to his lawyer:
The concept of braking energy storage into a flywheel which is later recovered by putting the energy into the compressor turbine of a turbocharger or simple supercharger (like the new Bendix unit).
So DeLorean is suggesting that the recovered braking energy be used to spin up a compressor (closer to a supercharger than a turbocharger, since it's not exhaust-driven) to add more power to the engine. It sounds like a great idea, and I believe this is the very first suggestion of such a concept.
If you're remotely interested in car engine design, I suggest looking over these rough notes. It's not just for the radical, exciting engine they describe, but also for the fascinating glimpse into how the mind of a truly gifted engineer works, especially in these early, rough stages that we so rarely get to see.
Read the notes, puzzle over the drawings, and imagine what could have been. And please feel free to talk about what you think in the comments, and further discussion is invited at DMCTODAY.COM.
Basic feature list of the engine.
Note the laser ignition reference in #3, and the interest in rapid commercial applications in #5.
The best part here is the "invent a scheme" option. That's always a great option.
"Sintered" refers to iron cast from powdered material.
Lots of interesting things here: gas or diesel, a "3 to 6" cylinder count, which may refer to the use or non-use of double-headed pistons, and the flywheel braking concept.
The wide diagonal shape is a cross-section of the swash plate, which replaces the crankshaft in a conventional engine.
This is a good image of the double-headed, domed piston in domed opposed combustion chambers. The link to the swashplate seems to involve round bearings.
Good cross-sectional view of the engine. The lower combustion chambers either don't exist in this version or the details (intake/exhaust ports, etc) aren't drawn in.
Interesting references to air bearing usage.
The doodles. That's what makes this one. I like to think he was on the phone, doodling these shapes.
That arrow is surprisingly like the Mac pointer cursor to come around four years later.
Material possibilities are considered here.
No waste gate is needed for the turbo is the regenerative braking energy is employed.
Overall, overhead layout options, witha 2 cylinder/4 piston variation.
Overall overhead layout with 3 cylinders/6 pistons, and central turbocharger.
One of the most detailed drawings of the hemi-head piston, and interesting information about the proposed air bearings, like that the air would be vented.
I think this is showing some details of the sleeve valves.
Air bearing system details.
Turbocharger positioning, general layout from the side.
This seems to be a novel idea for running the accessories from the pistons at one end?
Very novel cooling system ideas.
Laser ignition notes.
Early overall features list.
I'm not sure about the odd truncated-cone pistons there, but it doesn't seem to have been pursued.
The engine was estimated at 100 MPG here. Probably overly optimistic, but still interesting.
The letter to DeLorean's patent attorney.