Comments by "" (@EbenBransome) on "The INVERTED V12 🤯 Why!?!? - 3D animation - DB 600 Engine // Daimler Benz" video.

This is the kind of video that makes YouTube worthwhile.
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This story is repeated of just about every WW2 era engine being examined by another manufacturer, it's so old it has hairs on it whether it's Pratt & Whitney, RR, DB601, Merlin or whatever. Those engines were made with fixed jigs and tooling rather than CAD/CAM/CNC. Making the jigs and tools, providing the sharpening and adjustment data etc. only makes sense if you are tooling for large numbers. Bombing factories in WW2 was so imprecise that it was rare for tools and machines to be hit, and in any case there would typically be multiples on the production line. The cost of doing the metrology on a DB601 crank, then feeding it through to the program and tooling, would also be uneconomic for a single crank. Making it from billet would involve a great deal of machining, forging it would add to the tooling cost. You would also probably need to have details of the alloy in use and its heat treatment, which would involve testing the sample crank in different places for hardness, ductility and modulus. The 1940s engineering was as good as it could be but today we could easily design and make better engines - the reason we don't is that whole economy of scale thing, no new piston aero engines because the production volume wouldn't justify the sunk costs before production started.
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@johnarnold893 The industrial strength was quantity not performance. Individual German tanks, guns and aircraft were often better than Allied ones but could only be made in small quantities (indeed the main benefit of bombing Germany seems to have been the diversion of so much effort into producing the 88mm Flakcanone in volume.) The German joke was that one Tiger could defeat ten Shermans but the Americans always seemed to have eleven Shermans.
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Napier were pretty crap at sleeve valves. It was Bristol who perfected them and made them in volume, they had to help Napier with the sleeve design and manufacturing. The Bristol Centaurus produced about as much power as the double Daimler engine, from 18 cylinders. But by the time they were fully developed they were heading for obsolescence.
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@TheEulerID Your explanation is correct. I deleted rather than editing my original post for better clarity. I do take some issue with your other statements. Because of the greater viscosity of glycol, attention has to be paid to the flow paths especially in the cylinder head. But also high glycol mixtures have more wall adhesion in heat exchangers than straight water, so more circulating power is needed.
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The final versions of the Merlin and Griffon did more with less. The German problem was their eternal one - complicate, don't develop as such.
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@josephstabile9154 I think it was Daimler wanted to build a V-16 but the shortage of advanced bearing materials meant they would have had to use very large radius ball or roller bearings for the mains. Apaert from the cost, the Allies kept trying to bomb Schweinfurt, not perhaps very successfully but still risking interruption of production.
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@Kenneth-p1b The early Sabres had a host of faults including unforgivably poor quality control. It took Bristol to fix the sleeves and the EE takeover to get some shop floor discipline. I believe the common American belief that they productionised the Merlin and early examples they saw were handmade was confusion with a couple of Sabre samples sent to the US which had indeed been hand finished. RR was set up to produce Merlin engines in volume from the start.
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@TheEulerID The equation for efficiency includes a term for the expansion ratio, true. However the real reason Diesels are so efficient is that they draw in a full air charge at all loads, whereas a spark ignition engine varies the air intake according to load. Thus at idle the effective CR is small, and also the small amount of hot gas loses a lot more heat to the head and walls, while the full charge in the Diesel loses less heat in proportion. WW2 aircraft engines were designed to run at only a few powers - cruise, full power and emergency power - and could be designed to have fairly good efficiency, but to save fuel they needed to run as lean as possible, which tended to cause detonation, and avoiding detonation and a blown engine was more of a headache for the Germans than the Allies as they struggled to make good heat resisting valves. If the Merlin and Griffon had the cooled exhaust valve guides of the Jumo, they could have made even more power.
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@givenfirstnamefamilyfirstn3935 We were successfully stopping them from getting hold of the nickel, chrome, cobalt, manganese, tin, silver and so on needed to make engines like the Griffon. They did a lot with less. As a side note, people did wonder why the US invaded Morocco, so far west, when the focus was on northeast Africa. The answer, top secret at the time, was that Morocco had big deposits of copper, nickel, cobalt and manganese. And that, children, is how you win wars. By the end of the war they were having to insulate wires with woven cotton, and they were even short of materials for spark plug insulation.
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@dougerrohmer The Germans could make high octane synthetic fuel, but not as much as they wanted. Their problems with fuel were very complex - the particular analysis they used was more likely to knock with inverted cylinders and was better running rich, which meant less economy. Both sides developed engines and fuel in parallel based on what they could make, because they deviated so much each side couldn't use the other's engines at full power.
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Oil leakage causing detonation, and fuel diluting the oil, were problems with the DB series. The original Zündapp boxer motorcycle had a cylinder angle of, I think, 170 degrees or even less, so that the oil would drain back, at least in sidecar form. In my view BMW should have gone for a wide angle V. The difference in vibration wouldn't have been much, though it would be on the rather silly huge boxer they are now making.
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