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Merlins put out 2000HP on 150 octane fuel, and 2600HP on 150 octane and water injection. If I could increase my Honda's compression ratio, I could take advantage of 94 octane gas. There are absolute physical limits to what you can do with a piston engine, especially if you can't use tetraethyl lead.But then the eventual top developments of the Merlin were twice the power and the comparably sized Roll Royce Crecy tests pointed to eventually getting twice that again. Not to mention we can look to more power recovery from thermal excess and electronic engine management in addition. From 27 litres it is not unreasonable to think of having 6,000bhp to hand by now. As to what one might do with it is another matter. The Rolls Royce Crecy and Napier Nomad are, perhaps, the best OTL pointers (in different directions) to what might have been.
Well, there goes that plan. Thanks for ruining my weekend.A few side notes.
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Also do not ever forget that at about 21-22,000ft the Honda Fit engine would be making about 58hp due the the thin air.
So now you need to add a supercharger and provide cooling in the thin air.
The energy value of gasoline is not affected by the octane number. If your engine runs fine on 87 octane, it will run just as fine on 100 octane, i.e., no better, no worse. High octane numbers allow you to build engines with higher compression ratios, and it lets you run at higher supercharger boosts. For the latter, it helps if you have a supercharger.I have mentioned my 2002 Prius in other threads. I do not know what Compression Ratio it usually runs at with typical E10 (87 PN) fuel, but I have run it on E85 (100-105 PN) a couple of times and It ran just fine. MPG was the same as far as I could tell (by the estimator and by the pump), power was the same or better as far as I could tell, and it ran quieter (with E10 87 PN there is almost always a tiny bit of knock) - though there was some rpm 'hunting' on start-up.
The 1.5L 4-cylinder in my Prius has variable valve timing and can run upto 13:1 CR (in theory).
Swept wings to 35 degrees, huge turboprop engines at 15,000 shp each, contra-rotating propellors to reduce their size to where the tips won't run supersonic.Tu 95 top speed ~ 575mph.
Well, P & W and Wright and Bristol all put a lot of effort into large radial engines in the post war era. At least for the commercial market and for some military aircraft. It took a long time to get turbines to give long range (fuel economy) and at times they were pushing a little harder than the technology allowed.In the 1970's, with the supply of R-1340 engines that had not been rebuilt multiple times drying up, a company in California was taking the cylinders from R-2800 engines and modifying them to fit on R-1340 cases. The R-2800 was called the Double Wasp because in many respects it was just that, two R-1340's stock back to back. That is one reason the R-2800 was such a tremendous success from the very start with few teething problems; it was based on over a decade of R-1340 experience. But unlike the R-1340, the R-2800 development continued, adding superior materials and design features as compared to the earlier engines. In other words, we could go a lot further with other aircraft piston engine designs, even if we only brought them up to the 1945 level of the technology.
One of the biggest and potentially the easiest are the ignition systems. Magnetos are fine for lawnmowers, but we should not have to suffer with the things on airplanes, given that they have managed to combine all of the faults of poor reliability, high cost, excessive weight, awkward installations, absurdly short overhaul times, and lackluster performance in one handy unit. I doubt very much that there are any pilots who have NOT had to deal with a mag problem. We need two of the damn things because they are so unreliable, but since we have two not enough people get killed by them to force a better system design. The lawyers have made sure we have to suffer through with that 1930's hardware; non aircraft applications, such as industrial engines, got solid state replacements for mags 50 years ago. Finally, recently, a few companies have come put with modern replacements that can provid better reliability as well as radical new ideas such as advancing the spark to improve power, but even they require one of the old Depression Era units as a backup.For modern piston engines there are a few things that are stumbling blocks.
What you say is true.One of the biggest and potentially the easiest are the ignition systems. Magnetos are fine for lawnmowers, but we should not have to suffer with the things on airplanes, given that they have managed to combine all of the faults of poor reliability, high cost, excessive weight, awkward installations, absurdly short overhaul times, and lackluster performance in one handy unit. I doubt very much that there are any pilots who have NOT had to deal with a mag problem. We need two of the damn things because they are so unreliable, but since we have two not enough people get killed by them to force a better system design. The lawyers have made sure we have to suffer through with that 1930's hardware; non aircraft applications, such as industrial engines, got solid state replacements for mags 50 years ago. Finally, recently, a few companies have come put with modern replacements that can provid better reliability as well as radical new ideas such as advancing the spark to improve power, but even they require one of the old Depression Era units as a backup.
On a different tack, I spoke years ago with an ex Rolls Royce engineer who was given the exercise of seeing what power could be found from using Merlin exhaust gases in an afterburner.