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This Idea is a variation on the theme of starting a car manually, as with an old-fashioned hand crank, or kick-started like a motorcycle.
Suppose we have an N-cylinder auto engine (where N is always at least 2). Inside this engine, at the crankshaft, we insert a clutch between the first cylinder
and the rest of the cylinders. The first cylinder connects to the flywheel, and this cylinder alone is attached to the manual-start mechanism --here I'll imagine it to be a pull-cord, like on a lawnmower.
So, you disengage the clutch and manually start what is now in-essence a 1-cylinder engine. Afterward, you engage this special engine-clutch, so now the rest of the engine can be started very easily.
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You'd need to clutch the camshaft as well; otherwise you'd be turning the entire valvetrain. And you need to keep camshaft alignment so it has to be a single-position dog clutch.
Where does the ignition timing come from ? On modern vehicles the TDC sensor is usually on the rear flywheel. |
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[8th of 7], you could probably make always-separate valvetrains work. That would make it more like two separate engines than one "split" engine. Or, perhaps the valvetrains could be entirely eliminated; some modern engines use electric-solenoid-controlled engine valves. |
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// solenoid-controlled engine valves // |
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Ah, what a wonderfully innovative way to improve reliability ... |
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Have you never wondered why civil aircraft piston engines use magnetos, duplicated ignition systems, and carburettors rather than fuel injection ? |
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N would have to be at least 4, just so that each engine-half could be reasonably balanced. |
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This brings up nightmare images of split crankshafts, separate wet-clutch compartments and seals everywhere. You'd need two oil pumps because now there's a stonking great bell-housing in the middle of the crank shaft. |
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..why are we doing this again? |
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"The secret of comedic engine explosions" |
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//Almost like having two engines// |
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It would be simpler to have a model car engine which could be hand-started and then used to start the main engine or charge the battery. I'm not advocating this, just suggesting that it is simpler than the idea proposed. |
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Some V8s shut off 4 cylinders for efficiency at low power. I don't think rotating all of the shafts and pistons is a problem as long as you don't have to perform all the compression strokes. If you put an entire car on a spit, you wouldn't have a problem turning it with a handle. |
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The balance of this engine would be absolutely nightmarish and soon destroy its crankshaft. |
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