I did not know that MW-50 was corrosive to the engines. Can you tell me more about it.
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I'd like to hear how MW-50 corrodes engines also, although I don't necessarily doubt that for some reason unknown to me it did in the Messerschmitts it was installed in. I understand that a combat pilot of 109's referred to this. I just don't understand how it would. Nitrous oxide would damage an engine but MW-50 shouldn't at all (and they do have almost identical plumbing).Hop said:So I don't at all understand why C3 injection would be preferable to MW-50, except on limited run, early production test engines whilst the bugs are being sorted out.
It's preferable because it means you don't require a separate tank and plumbing for the MW50, which means less weight, or you can carry extra fuel in the place of the MW50, which means more range.
It also doesn't have the corrosive effects on the engine MW50 had.
Blower efficiency is directly proportional to temperature, water injection lowers blower temperatures,
So, as I understand it, did C3 injection.
And MW-50 is a water injection system which is completely different, operates completely differently and its function is completely different.There were two (2) grades of aviation gasoline produced in volume in Germany one the B-4 or blue grade and the other the C-3 or green grade. Both grades were loaded with the equivalent of 4.35 cubic centimeters tetraethyl lead per gallon. The B-4 grade was simply a fraction of the gasoline product from coal and coal tar hydrogenation. It contained normally 10 to 15 percent volume aromatics, 45 percent volume naphthenes, and the remainder paraffins. The octane number was 89 by a measurement corresponding to the C.F.R. motor method. The C-3 grade was a mixture of 10 to 15 percent volume of synthetic isoparaffins (alkylates and isooctanes) and 85 percent of an aromatized base stock produced by hydroforming types of operation on coal and coal tar hydrogenation gasolines. The C-3 grade was permitted to contain not more than 45 percent volume aromatics. This aromatic limitation sometimes required that the base stock component include some diluents other than the aromatic fraction, which could then be balanced if necessary by the inclusion of slightly more isoparaffin. (The C-3 grade corresponded roughly to the U. S. grade 130 gasoline, although the octane number of C-3 was specified to be only 95 and its lean mixture performance was somewhat poorer.)
Which led me to think you understood how it worked. I know how that works. I'm not trying to be rude, just stating the facts. Trust me, the basic engineering principles apply whether a car or aircraft engine. High octane fuel is high octane fuel and water injection is water injection. They are different.C3 is the German designation for their 'high test' fuel. B4 is the designation for 'regular' grade fuel. 190s with the BMW801 required C3 grade fuel.
KK,KraziKanuK said:vanir,
MW50 only cools the cylinders indirectly because the fuel mixture in the induction system has been cooled by the injection of MW50.
Inject any fluid into the front end of the induction system and the fuel mixture temperature will be lowered by vaporization.
Btw, the British carbs did the same thing, lower the fuel mixture temperature(slightly). Have you not heard of carb icing? Even cars can have icing problems.
You are confusing 'fuel injection'. The Germans used direct fuel injection and I agree that 'injecting' more fuel at the cylinders is of no help. Inject it at the front end of the induction system, which BMW did for the 801, it acts the same way as MW injection. C3 injection uses the same plumbing as MW injection.
Maybe this link will help with your confusion, www.forums.ubi.com/eve/ubb.x/a/tpc/f/63110913/m/9991053533/r/5711054833
That's right. I'm claiming martian soil was used to strengthen German airframes.Vanir, are you claiming that C3 injection wasn't used?
No it doesn't. It shows C3 fuel was used. C3 is a fuel. F-u-e-l. I've been reading quite a bit about the BMW 801 in the last few days.The original documentation shows it was.
And here is a link for the allied report on engine testing the BMW 801:To quote from an allied description from captured aircraft:
He might as well have called it Super-duper power producer. The allusion is clearly incorrect, port injection is a LONG way from the air intake for a start. It's just outside the cylinder."Extra Emergency Performance (Fuel injection into air intake)
Yeah compared to the carburettors on Merlins maybe. Context is important and this guy is obviously comparing direct injection to carburettors.This system is used on the BMW 801 D to increase the emergency performance. It provides for the overriding of the boost regulator and the simultaneous injection of C3 (96 octane) into the port air intake to prevent detonation and provide internal cylinder cooling."
It doesn't say secondary spray nozzle and doesn't have to be read that it does. Perhaps if you post a link to the document I'll be able to tell you what is meant by "second cock" on the fuel pump valve, I'd say one drives a mechanical fuel pump and the second opens the valve, from here."The second cock opens a pipe line from the fuel pump to a spray nozzle fitted into the port air intake. The spray nozzle is calibrate to pass 14.3 +- 1.43 gallons per hour at a pressure of 18 to 25 lbs sq in"
Okay this is getting boring now.
No it doesn't. It shows C3 fuel was used. C3 is a fuel. F-u-e-l. I've been reading quite a bit about the BMW 801 in the last few days.
Engine blueprints show no additional fuel injection system was used in the air intake nor anywhere else.
He might as well have called it Super-duper power producer. The allusion is clearly incorrect, port injection is a LONG way from the air intake for a start. It's just outside the cylinder.
Yeah compared to the carburettors on Merlins maybe. Context is important and this guy is obviously comparing direct injection to carburettors.
How many ways can I put it? Fuel injection at the AIR intake does not cool down cylinder temperatures, I've already mentioned this
PORT injection is not fuel injection at the air intake.
The bit that says "to prevent detonation" is the higher octane rating of the fuel.
The bit, "to provide cylinder cooling" is just a general reference to direct injection systems as opposed to carburettors or throttle body fuel intake, he's giving a general description of multipoint fuel injection, also known as direct injection and may be at the port, intake manifold or cylinder. If it was cylinder injected he'd be saying, "to provide cylinder cooling," precisely as he did for port injection. If it was manifold injected he'd be saying, "to provide cylinder cooling."
Say hello to direct injection vs other fuel delivery systems.
And how many ways can I put this part? C3 is not a fuel delivery system it's a fuel (95 min. octane motor method or as high as 130 rated octane at the pump).
Your out of context insinuation is that the BMW 801D used a special fuel injection system in conjunction with this fuel. It did not. It used precisely the same fuel injection system as all BMW 801 model radial engines.
BMW used port injection, which is about four inches further back. It has absolutely no opportunity whatsoever to cool intake charge.
It doesn't say secondary spray nozzle and doesn't have to be read that it does. Perhaps if you post a link to the document I'll be able to tell you what is meant by "second cock" on the fuel pump valve, I'd say one drives a mechanical fuel pump and the second opens the valve, from here.
If the BMW 801D had a secondary fuel injection system installed I should think this would have been mentioned on at least one document I have read or I should be able to find it on the engineering blueprints for this engine. No on both counts.
I understand such a system is the assumption of some of you. It is simply misguided by out of context statements and poor descriptions.
It is clearly stated in several documents relating to the BMW 801 series engines that the D variant did not change or alter its injection system to any other variant but simply used a higher octane fuel.
When you do that, you can change your boost settings. That's how they got more power.
Wanna know how? You get the boost regulator and a hacksaw...
I'd like to mention I appreciate basic engineering principles being attributed to theories of mine, however injecting fuel ahead of the supercharger cools the supercharger and heats the mixture.Vanir, you've got a theory that injecting fuel ahead of the supercharger isn't going to provide usefull charge cooling, and therefore it wasn't used. In fact it was, it was used in later 190s to enable extra boost, it was also used in Merlins throughout the war for it's charge cooling effects.
History doesn't say it did. You do. You've so far offered no corroberative evidence to support these claims. Anecdotal evidence simply won't do for supporting claims which challenge engineering principles and printed technical documents. If you'd like to suggest an additional fuel delivery system to the BMW 801D in Fw190's which does not appear on technical specifications and documentation please provide some clear evidence for it.When a theory says that something won't work, and history says it did work, it's time to re-examine the theory, not to try to change history.
Nothing I've seen documents this. There is no reason to think a system which appears nowhere but the claims of a couple of individuals should exist where it does not on any technical documentation. Please provide proof.Fairly late in the war they began injecting the fuel into the air intake ahead of the supercharger for it's charge cooling effects, that's what "C3 injection" describes.
That's just not how boost pressure regulators work. You said, "it has nothing to do with the fuel system." I say, it has nothing to do with "the throttle opening more fully."Or you operate the lever that opens the first cock that bleeds air into the regulator allowing the throttle to open more fully allowing higher pressure.
This is the type of supercharger used on the BMW 801-series.Although many roots and twin screw superchargers bolt directly to the manifold, most centrifugal superchargers require an extra tube called a Discharge Tube to carry the air to the intake {edit: ie. the HEAD PORTS} through the throttle body.
This problem is accentuated by the radial engine being air cooled in the first place.Some supercharger systems include an aftercooler (more commonly called an "intercooler"). Superchargers heat air as it is compressed. Although the intercooler is not necessary on most street applications, its performance becomes increasingly important on higher-output systems (with correspondingly higher charge temperatures).
Intercooling and aftercooling may also be provided by water injection in the discharge piping.An aftercooler is a heat exchanger placed between the compressor and the engine's inlet. Vortech uses the term "aftercooler" as we feel it is more accurate; it is "after" the compressor. "Intercooler" means a heat exchanger placed between two compressors in a multi-stage system, but has been used as a synonym for an aftercooler ever since it was incorrectly stuck on the backend of a Volvo in about 1981. Aftercoolers and intercoolers are both also called charge coolers.
Using fuel delivery at the air intake increases the density of air, causing a proportionate increase in temperature above and beyond the original air-charge compression. Even if it's say 10 degrees cooler going in because you decided to mount a draw-through carburettor like Merlin did, it ends up 50 degrees hotter coming out the other end than it would've otherwise, due to the increased density. As I mentioned, with leaded fuels the problem is compounded by the lead in the fuel which holds onto that heat rather stubbornly during any subsequent "intercooling."For heat exchanger design purposes, the gases in air are classified as a low-density fluid. Air going through a supercharger is called "charge air". A supercharger compresses the charge air before it enters the engine. The act of compression both increases the energy and density of the charge air, but this act also generates a proportionate amount of heat. Heating is undesirable, as it tends to decrease the density of the charge air.
Try posting, displaying or linking to any blueprints at all.Try looking at the correct blueprints.
Not according to the pictures, one of which I posted a link to in pdf format. You can tell it's the fuel injector because it has a little arrow to it marked "fuel injector." You can tell it's the C3 fuelled engine from an Fw190 because it has bold print that says "BMW 801D engine."No, he means port as in left, as in the opposite of starboard. Fuel was injected into the left air intake.
How do either of us really know he wasn't comparing it to the Space Shuttle. Yes, he was a seer, a Celt and a magician. He's right here in fact and he wants his pointy hat back.No, he's comparing the 190 to the later 190 with fuel being sprayed into the air intake.
No I think you're making a completely unqualified assertion based on what you've decided to assume without cross-referencing and seeking to correlate your data. If you could show me a picture of this system you've imagined at the engine air intake, I'd really appreciate it. I think it was simply a poor description when what was meant was head-port intake. That one thing would explain everything (occam's razor anyone?).Read the description. "a pipe line from the fuel pump to a spray nozzle fitted into the port air intake. The spray nozzle is calibrate to pass 14.3 +- 1.43 gallons per hour at a pressure of 18 to 25 lbs sq in"
Do you think he's imagining that?
Mate, saying things like that as an argument is just childish where you don't provide the proof so that we may both observe it together.It's a matter of historical record.
As you can see it clearly states the BMW 801D achieved its higher output through the use of greater supercharger gearing and a higher static compression ratio for which it required the use of C3 fuel.Der 801 D und G wurden als leistungsgesteigerte Version entwickelt. Die Leistungssteigerung erfolgte durch eine geänderte Laderübersetzung und eine höhere Verdichtung in Verbindung mit 95 Oktan Kraftstoff. Die erreichte Leistung lag bei 1270 kW (1730 PS) bei 2700 Umdrehungen pro Minute. Der Ladedruck stieg auf 1,39 bar abs. (abs.= absolut), gegenüber den 1,27 bar abs. bei dem A, und die Volldruckhöhe lag bei 5700 m.
The fact that it didn't mention any different fuel injection system between the C3 injected and M4 injected variants is what initially pricked my interest and led me to continually check further, more technical source materiel.These were soon replaced with the 801D series engines, which ran on C2/C3 100 octane fuel instead of the A/B/C's B4 87 octane, boosting takeoff power to 1,700 hp (1,250 kW) in the D-1, and 1,730 hp (1,270 kW) in the strengthened D-2. The D models also included a system for injecting a 50-50 water-methanol mixture (known as MW50) into the supercharger output to cool the charge, and thereby reduce backpressure. Although practically every production model 190 included the 801D engine, it was not until very late in the war that the MW50 kits were actually supplied and available.
Wow, direct fuel injection. Not at the left hand side air intake. Hang on, must be a different engine...nope it's the C3 injected 801D.The BMW 801D was a 14 cylinder, twin-row radial with direct fuel injection.
Beginning in the spring of 1942, series production of a more powerful engine version BMW 801D-2 that replaced previous versions in the Fw 190Fighter created a new plane version designated as Fw 190A-3. The increase in the BMW 801D-2 engine power (to 1730 kW) was due to a higher compression ratio and higher pressure two-speed compressor. A higher compression ratio and charging pressure made it necessary to use high-octane (96 octane) C3 fuel in place of B4 (87 octane) fuel.