Aces High Bulletin Board
General Forums => Aircraft and Vehicles => Topic started by: MiloMorai on August 10, 2004, 11:50:41 AM
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http://109lair.hobbyvista.com/articles/airframes/413601/413601_report.htm
Of special interest is the engine boost limits.
(1) On deliver flights or test flights after an engine change, after take-off do not exceed 2,100 r.p.m. and 1.05 ata of boost. If possible duration of flight should not exceed one (1) hour. Watch oil pressure.
(2) For the first five (5) hours, if possible do not exceed 2.300 r.p.m. and 1.15 ata boost.
(3) For the second five (5) hours, if possible do not exceed 2.600 r.p.m. and 1.30 ata boost
(4) After ten (10) hours, the aircraft may be flown if necessary without limitations other than those laid down in current instructions.
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"After an engine change" being the important part. All engines needs to be run-in, before they can be pushed to operational power levels.
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And your point is?
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Stating the obvious but you omitted the "On deliver flights" part.
Considering the number of Allied a/c in German airspace, delivery flights and break-in flights must have been nerve racking for the pilot. How long a flight time from Augburg to Holland and France at 1.05/2100rpm? (Augsburg > Paris ~600km, Augsburg > Deelen(Arnhem) > ~550km)
Did you read the report? Of further interest is the time limits for the different boost pressures.
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On delivery flights or after engine change the engine needs to be run-in. Why is this a surprise to you? These aircraft would not be used operationally until they were run-in, and full power could still be applied, but at a serious cost of wear and tear on the engine, and increased risk of malfunction. The skies over Germany in early-mid 1944 was not that full of allied aircraft, and those that were there were up high protecting bombers.
The time restrictions were not a surprise either, and have been posted many times before. What new information do you see on that site?
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Originally posted by GScholz
On delivery flights or after engine change the engine needs to be run-in. Why is this a surprise to you? These aircraft would not be used operationally until they were run-in, and full power could still be applied, but at a serious cost of wear and tear on the engine, and increased risk of malfunction. The skies over Germany in early-mid 1944 was not that full of allied aircraft, and those that were there were up high protecting bombers.
The time restrictions were not a surprise either, and have been posted many times before. What new information do you see on that site?
LOL, no surprise (done it many times) so why are you still harping on the obvious. :rolleyes: :(
I did not say over Germany but German airspace. There is a difference. German airspace includes France and the Low Countries. :eek: Considering the Allies were swamping these areas with a/c in preperation for invasion, re-placement and re-engined a/c would be not that safe. Now what after mid 1944? The 8th AF was almost flying un-molested over Germany itself.
Time restrictions > to re-fresh some peoples memory.:)
New info? Well the trim and flap wheels were made of wood.
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What does that have to do with anything in AH? Do you expect us to have to run-in the engines on every aircraft before we play? If not, why is this information "interesting" ... it's a GIVEN that engines needs to be run-in. Have you never bought a new car?
However you still ignore that fact that the engines could still operate at full power in an emergency, however the engine would have to be replaced again and overhauled. These boost restrictions are to prolong the engine life, and to assure nothing is wrong before operational service with the aircraft.
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Originally posted by GScholz
What does that have to do with anything in AH? Do you expect us to have to run-in the engines on every aircraft before we play? If not, why is this information "interesting" ... it's a GIVEN that engines needs to be run-in. Have you never bought a new car?
However you still ignore that fact that the engines could still operate at full power in an emergency, however the engine would have to be replaced again and overhauled. These boost restrictions are to prolong the engine life, and to assure nothing is wrong before operational service with the aircraft.
Ah poor little Sholzi is all upset. Who stuck the burr in your knickers?
This is the Geneal Forum > A/C and Vehicles forum. Many threads have been non AH related. :) Not necessarily anything to do with AH. Not everyone is as knowledgable as you.:rolleyes: :) They might not know what was involved in breaking in a DB605 engine. Besides that, it is a British report on a G-14.
No I don't ignore the fact that the engines could be run at above the break-in boosts and rpms, in an emergency. But as you say the engine would have to be replaced and that is normally an eight (8) job for 3 men. As if the 'black men' did not have enough to do.:rolleyes: Changing tires, batteries, regular maintainance, polishing the airframe, interupted by air attacks, etc, etc. What was the supply situation? Were engines readily available? Or did you forget the transportation system was breaking down?
As I said before, I have 'broken in' many engines, specific > the race type, so you can stop harping on the obvious.
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What made you think I was upset? *lol*
We all know the Germans lost the war. You're just repeating things that everybody already knows. This discussion is of no value.
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This is somewhat off-topic, but...
Is the G-14 better than the G-10?
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VERY INTERSTING. Even the G14 had 200 rounds capacity in the 20mm magazines.
"None of the guns had been fired and its was found that the ammunition tanks had not been completely filled.
Tank capacity Rounds carried
20 mm. ... 200 per gun ... 150
13 mm. ... 300 per gun ... 275
The Revi 16B gunsight was used."
AH now gives us 200 rds in F4 and G2. It seems also we should have vthis option on G6 and G10...
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Originally posted by GScholz
What made you think I was upset? *lol*
We all know the Germans lost the war. You're just repeating things that everybody already knows. This discussion is of no value.
Well Scholzi, you are the only one repeating ones self, ad nausium.:rolleyes: Sounds like you are upset because your supermen could not do the job. :p Now put the muzzle back on that long snoot.:)
Take a hint from the last 2 posters.:) They seem to like the link, except for your manure. One even makes a comment about an application relevent to AH.:eek:
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*lol* You really do live up to your nickname MiloMoron.
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That link has some interesting info in it Milo. But GScholz has a point...I'm kinda wondering myself why you picked the engine break-in procedures out of all that. That's like worrying about the breed of cows used for the seat leather.
Anyway, cool link.
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Actually Milo I think your emphasis on the need to run in brand new engines carefully in order to ensure long engine life is kind of mundane, was this supposed to be significant info? Is it supposed to a new attack in the rearded series of 109/spit/enine/prop/fuel efficency threads between you and isegrem?
But thanks for the cool link anyway...
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What`s the news about that...? This report is on the Lair for ages... every brand new engine needs to be run first on low power settings, so that the parts can 'fit' to each other. Car, airplanes, all go the same way.
In fact, there`s one part in Tobak`s book about 'putting in hours' into the new G-10s they received. Somehow they done it. ;)
As for the wooden parts in the cocpit, yep, they were in increasing use in 1944, the tail unit was made of wood (that ensured inproved aerodynamics, but was some 2-10kg heavier), and in the cocpit, trimwheels, the bomb fuse panel, sometimes the cocpit floor and the pilot seat was made of wood reducing the pressure on the metalworking shops and allowing them to produce more of the more important parts. Wood or metal, in these things it didn`t make a difference in functionality.
It`s just another stupid flamebait thread Milo regularly use to post as he can`t receive any attention via a normal conversation.
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LOL.
It is rather OBVIOUS that a new engine needs a break-in time. Anyone with any resemblance of intelligence knows this. What is mundane is the Luftluvers stating the obvious, repeatably.
Phookat I did not know what the times were. There was other info that was new for me and thought some others might like to read the report who did not know of it. But, instead of making any worthwhile contributions, the Luftluvers, like Barbi and Scholzi, go flaming. But what else does one expect from them.:rolleyes:
Barbi, 2 posters enjoyed the link.:) And, Barbi, I would not mention flame bait posts. Your Spit 2100mi. range post is a prime example. When have you had a civilized conversation Barbi? They always turn into flame fests because of your German is UBER fanatism, with you insulting and demeaning those who do not agree with you.
The 190 had wooden parts, as was the cockpit floor of the P-51.
As to your comment, re Tobak. I would not want to be in a German a/c before that 10hr period ended during the last 12-16 months of WW2. To give you an example, I blew and engine and had to put in an engine that was not fully broken in. Seized during the race. Good thing I was not at 1000m.:)
So who has the break in times for other aero engines? WELL???
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Originally posted by Fruda
This is somewhat off-topic, but...
Is the G-14 better than the G-10?
A G-14 is a G-6 + MW-50.
Its not as fast as the G-10. The G-10 has a DB605D eng. The G-14 has a DB605AM.
The non-AS G-14 and G-10 have different superchargers.
The G-14 in FB/AEP is most fun plane ever to fly in any game ever.
AH needs one desperately. :p
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To add to Wotan, Germany initiated two projects in 1944, which was to 1) develop a successor to the G model 109, and 2) bring up production G model performance to the standards of the new 109.
The first was to become the Kurfurst, and the second was to become the G-10. Except the developments for the Kurfurst lagged behind schedule, so the standardization process of the G models came first, and factory built G-6s were now formally equipped with the DB605A with MW50 systems installed, plus some minor field modifications integrated into the factory model. This improved 'makeshift' G-6 became the G-14.
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I find strange the alledged lack of armour and the armourless fuel tank?
What was the standard armour on these machines after all? There is the layered thick duraluminum bulkhead between pilot and fuel tank but despite that?
AFAIK the fuel tank had a rubber sack inside the aluminum cover so when the fuel was drained there was not dangerous space left for air which would have made a single hit of incendiary lethal. So those fuel tanks were not usually armoured at all but considered as armour themselves. Can anyone confirm?
-C+
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IIRC from the last time that report was posted that particular G-14 was a recon version. The fighter version has a self-sealing fuel tank, Galland armor and windshield armor.
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Originally posted by GScholz
IIRC from the last time that report was posted that particular G-14 was a recon version. The fighter version has a self-sealing fuel tank, Galland armor and windshield armor.
If it was a recon version, why no mention of cameras? It could have been on a recon type mission. The G-8 (recon type) also had the FuG16 replaced by the FuG17 but this a/c has the FuG16. Of the known NAG units (1,2,3,4,14) that flew G-14s, it seems none had bases in the West at the time. (http://www.ww2.dk/) Why the conclusion that it was a recon G-14?
The canopy was not found for this G-14 but windshield armour is mentioned - G-14s had the Erla hood, Galland armor.
Where in France is Fontenay-le-Poesnel?
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Originally posted by Charge
I find strange the alledged lack of armour and the armourless fuel tank?
I think I have a very simple explanation for this, which I already told to George who supplied this report and he liked the explanation quite a bit.
If you look at the serial no. of this G-14, you will notice it`s from the same 41x xxx series block as the G-6/U2 the Brits also caputured. Now the /u2 suffix means it`s a factory mod for GM-1 carrying, ie. it was intended as a special high alt variant. Quite often those ones were lightened quite a bit, removing the heavier s-s tank and putting a light alloy fuel tank in it`s place. Not sure about, but perhaps the rear armor plates were removed as well. Since these fighters were supposed to do task like intercepting high flying bombers, or unarmed FRs, the armor wasn`t a neccesity, just a burden. So what I think this early G-14 was a conversion from an older G-6/U2, which was easy as those already had the piping, and an easily convertable rear tank for the MW50. The 'lightened' tank and removed? armor was kept, probably. Of course newly built G-14s would have a normal level of armor, as described below.
What was the standard armour on these machines after all? There is the layered thick duraluminum bulkhead between pilot and fuel tank but despite that?
[/B]
If you mean the standard fighter G-14, not these hybrid expceptions, it was 90mm built-in armor glass on the windshield, a 60mm armored glass in the headrest enclosed in a 10mm steel frame, a 8mm back armor plate behind the dural/wood pilot seat, and 4mm armor seat starting under the butt-level of the pilot reaching until the cocpit floor.
The 25mm multi-layer dural plate that was further behind and protecting the fuel tank (and the pilot as well of course) was removed on the MW50 carrying 109s, to make space for the 115 liter MW tank. However, I guess the MW tank itself provided a considerable level of protection, especially vs. incendinary rounds, being quite large in itself, and filled with water mixture which would slow down bullets just like fuel tanks, a bit better in fact, since water was more dense. I wonder how it related to the 25mm layer itself in protection value(which, as per reports, could provide complete immunity for the fuel tank itself from .303 fire, and a rather safe protection to the pilot from .50cal AP, as it had to pass the bulkhead, the fuel tank itself, the pilot`s 8mm armor, the pilot seat, plus whatever got in the way in the fusalage itself). .
So I think we can say a 109 pilot was protected against enemy shots well above the avarage fighter protection level.
AFAIK the fuel tank had a rubber sack inside the aluminum cover so when the fuel was drained there was not dangerous space left for air which would have made a single hit of incendiary lethal. So those fuel tanks were not usually armoured at all but considered as armour themselves. Can anyone confirm?
[/B]
IIRC the 109`s self sealing tank was a large piece of rubber, and was kept from bulging out by a plywood filling between it and fuselage. Putting metal near the fuel tank is generally a bad idea, `cos even richocheting hits from metal can create sparks and ignite fuel fumes..
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Many re-engined 109s would have only been ferrying from Holland. There was a huge rebuild factory there.
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So, the G-14 is a superior G6, that out-performs the G2, or am I wrong?
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you're right :)
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Then, damnit, we need it too!
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Originally posted by Fruda
So, the G-14 is a superior G6, that out-performs the G2, or am I wrong?
G-14 is basically a G-6 with MW50 boost, and 1800 HP instead of 1475. The result is much improved low/medium altitude performance (530->569km/h on the deck).
In fact, the G-14 is equal, if not better than the G-10 on the deck, up to about 5000m, where the G-10`s better supercharger come into play.
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Recon does not mean photography. Reconnaissance is a term that encompasses a lot of military roles. This G-14 was probably a recon fighter ... a scout. The LW frequently used scouts to identify the bomber streams as they entered German airspace, something radar alone could not do. Special lightened versions of the 109 were used, and this one looks like such a scout 109.
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Originally posted by MiloMorai
So who has the break in times for other aero engines? WELL???
Your ignorance is amazing. Why do you think the break in times would be any different?
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Originally posted by mora
Your ignorance is amazing. Why do you think the break in times would be any different?
Enlighten me, oh yee with such GREAT knowledge. :rolleyes:
Instead of just flapping your gums :eek: :eek: :eek:, post some info for P&W, R-R, Bristol, Allison, Napier, Wright, Jumo, Fiat, Nakajima, Mitsubishi, Mikulin, Shvetsov, Piaggio, Klimov engines.
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A Break in of an engine is needed because there are always tolerances when moving engine parts are machined. During the break in period the engine parts are supposed to set together to achieve optimum tightness. The smaller the tolerances are, the shorter the reguired break in period, hence new cars for example don't reguire any break in period because machining tolerances have been lowered in recent decades and oils have been getting much better. I have no reason to believe that German manufacturing tolerances during WW2 were any higher than those used in GB, USA, Soviet Union, Italy, Japan etc.
The duration of the break in period you posted(10h) actually seems quite low and is probably too short to achieve optimum engine life. However during war time conditions this was more acceptable than all the hassle with longer break in.
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Even today car manufactors (still) recommend not to exceed 3000rpm the first 1-2000km in a car.
niklas
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All engines need a run-in.
For what it's worth though, an old 109 Pilot told me that he was not satisfied with the late DB engines. They would wear out way too quickly he said, and getting to know a captured Mustang with an impressive engine time on the clock, he was very impressed with it. "Our engines were not that good" he said.
I don't know what to read out of it though. The DB design was indeed very good. Was it lack of maintainance and material, and the use of MW perhaps.
I'll try to ask him better later.
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In Gabreski's book (Gabby, A Fighter Pilot's Life), Frank Klibbe tells: " Airplanes were assembled up in northern England, and then flown down to the units. And the engines had to be slow-timed. This meant you had to fly 10 hours of time at low rpms on the engine before you could really open it up to its maximum. So, after each mission I'd jump into this new P-47 and go up to put on an hour or two."
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Angus, are you mixing up MW and GM again? MW was not harmful to the engine, GM was.
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GM?
Maybe. MW is Methanol-Water right?
GM is what?
Anyway, not so well in on these exact things, I'm all ears though.
The old guy sort of embarrased me, you see, for these things were being discussed by a group of people, where I gave the impression that the German machinery had always more or less been on the top. He looked at me and shook his head (tsk tsk tsk).
(Actually, he already told me this engine story by then. The pilots would measure the tightness of their cylinders by turning the prop. The late DB's wore up really fast. Therefor he was amazed to check out a P51 with an impressive figure on the clock, yet the prop was totally stiff. He later flew the 51 and was extremely satisfied with it.)
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Yes, MW is water-methanol, which is harmless to the engine. GM-1 is nitrous oxide, which is very corrosive. Technically the DBs were more advanced than the Merlins, much more advanced in fact. However given the state of Germany's supply and production problems late in the war the engines were not made with the specified quality of materials and production, in fact a great deal of research went into studies of how to use cheaper/more abundant materials in production. This gave the engines a shorter life and a higher risk of malfunctions. However this was less important to the Germans as they were fighting over their own territory. The Allies OTOH needed reliable long-life engines because their planes were flying for several hours every sortie, and they were flying over enemy territory.
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Originally posted by GScholz
Yes, MW is water-methanol, which is harmless to the engine. GM-1 is nitrous oxide, which is very corrosive.
Hmm, are you sure about that? I thought it was the opposite. Coming from a car perspective...if you want to run a methanol-powered car, you have to make sure your fuel system etc is stainless steel to avoid corrosion.
Nitrous, OTOH, requires no such precautions. Squirt it in, and let the N2 split from the O in the cylinder as the piston rises. And of course spray extra fuel to burn with the extra O. You still have to worry about preignition just like a forced-induction engine, but no corrosion problems AFAIK.
That's why Nitrous upgrades to cars are fairly common, while methanol injection is not.
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No water-methanol is injected into the eye of the supercharger where it evaporates cooling the charge. This cooling allows a higher pressure before fuel would detonate. Its not injected into the cylinders and its not a fuel additive or fuel itself. It is not burnt.
Methanol is added to keep the water from freezing. I believe it evaporates faster then water.
GM1 couldn't be run below 7000m.
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Hi phookat,
>Nitrous, OTOH, requires no such precautions.
Both the Germans and the British also experimented with liquid oxygen, which was quite corrosive. Nitrous oxide was preferred because it was trouble-free in that regard.
>Coming from a car perspective...if you want to run a methanol-powered car, you have to make sure your fuel system etc is stainless steel to avoid corrosion.
I'm not sure whether that helps, but the MW50 system was separate from the normal fuel system. The MW50 (50% methanol-water mixture) was sprayed into the supercharger air intake, were it would evaporate. I guess the high speed of the intake air might reduce the corrosive effect in the intake system.
>That's why Nitrous upgrades to cars are fairly common, while methanol injection is not.
I guess car owners like to get more running time out of their engines than WW2 fighter pilots, anyway :-)
MW50 reportedly was hard on the spark plugs, which had to be changed frequently. Other than that, it seems to have been mostly trouble-free, too.
Oh, running an MW50 tank dry would have busted the engine, but as a pressure sensor cut out the extra boost if MW50 supply was exhausted, that was not a real problem.
Regards,
Henning (HoHun)
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Originally posted by Wotan
No water-methanol is injected into the eye of the supercharger where it evaporates cooling the charge. This cooling allows a higher pressure before fuel would detonate. Its not injected into the cylinders and its not a fuel additive or fuel itself. It is not burnt.
Methanol is added to keep the water from freezing. I believe it evaporates faster then water.
So this is really water injection, with "antifreeze" added. Understood.
But regardless, if methanol goes into the compressor side of the SC, it goes into the cylinders, and it *does*get burned. I would imagine that the SC would have to be stainless or something to avoid corrosion. Maybe the rest of the intake and cylinders would not be affected as much if the methanol is a gas...but I doubt it. Still think it would be subject to corrosion. But even if the cylinders/intake weren't more corrosion resistant, as HoHun says, the engines weren't supposed to run 200,000 miles like a car. ;)
Originally posted by Wotan
GM1 couldn't be run below 7000m.
Probably just because of head cooling considerations. Intercooling/watercooling doesn't work as well for pure nitrous, since the pressure build-up (and the resultant heat build-up) happens inside the cylinder rather than in the intake/plenum.
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Originally posted by HoHun
Both the Germans and the British also experimented with liquid oxygen, which was quite corrosive. Nitrous oxide was preferred because it was trouble-free in that regard.
Yes, makes more sense to me.
Originally posted by HoHun
I'm not sure whether that helps, but the MW50 system was separate from the normal fuel system. The MW50 (50% methanol-water mixture) was sprayed into the supercharger air intake, were it would evaporate. I guess the high speed of the intake air might reduce the corrosive effect in the intake system.
Yes, I'll admit that's possible. Both the fact that there is much less of it (cooling injection rather than main fuel), and the fact that it is gaseous mitigate (but don't eliminate) the corrosiveness.
You can get methanol additives for cars too (say 3% fuel volume, or so). But even at that small percentage it is recommended that you run the tank down as quickly as possible.
Originally posted by HoHun
MW50 reportedly was hard on the spark plugs, which had to be changed frequently.
Hmm, that's a little suprising. Do you know if that was from fouling/carbon build-up, or corrosive effects?
Originally posted by HoHun
Oh, running an MW50 tank dry would have busted the engine, but as a pressure sensor cut out the extra boost if MW50 supply was exhausted, that was not a real problem.
Cool. Yeah, seems like these German engines were pretty far ahead of their time, as far as engine management functions.
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Heh I know only one car which did use methanol-water mixture: it was 60s Oldsmobile Jetfire.
Car had turbocharged V-8 and just like german engineers guys in GM thought that MW50 would be answer to detonation problems at higher boosts.
IIRC these systems could be driven dry without boost cut and engines weren't too happy getting full boost without methanol-water mixture.
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Originally posted by HoHun
Oh, running an MW50 tank dry would have busted the engine, but as a pressure sensor cut out the extra boost if MW50 supply was exhausted, that was not a real problem.
Regards,
Henning (HoHun)
I didn`t know that, even though I suspected it didn`t just go boom if MW was suddenly not injected (damaged lines, for example). Are you sure it worked that way ? I will add that to my site, don`t want to put rubbish in there not even by accident.
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How is methanol corrosive? It is just alcohol. Methanol is used to clean engine parts for oil/grease. Water OTOH is corrosive to iron alloys, but as long as the engine is lubricated properly and run for a while without water injection, it should not be a problem. Water is only corrosive if it is allowed to stay in the engine for a while, and normal lubricant oil should protect the engine parts. Every engine swallows water now and then, and the air can be very humid sometimes. Never hurt an engine as long as it has oil.
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Pretty much as Gscholz said; Jane`s WW2 Aircraft says that an unspecipied (i think the jumo213 or the DB 605D) German engine needed to be checked after 50 hours of operation for signs of corrosion, if MW50 injection was used. That`s quite a long time for a wartime engine, chances were that the engine was already destroyed by the time the check would be neccesary - even with very low loss rate, ie. 2%.
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Originally posted by GScholz
How is methanol corrosive? It is just alcohol. Methanol is used to clean engine parts for oil/grease.
Not sure what the exact chemical process is, but I do know it is a concern with car engines. Hell, I know for sure it affects RC engines. They run on methanol, and if you leave fuel in the engine for a while it will rust solid.
It might just be the hydrophobic nature of methanol, but I think it is more than that.
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Alcohol will suck every last bit of humidity out of the air, and if left in the engine the water will corrode the metal. The alcohol itself is harmless.
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Originally posted by VO101_Isegrim
Pretty much as Gscholz said; Jane`s WW2 Aircraft says that an unspecipied (i think the jumo213 or the DB 605D) German engine needed to be checked after 50 hours of operation for signs of corrosion, if MW50 injection was used. That`s quite a long time for a wartime engine, chances were that the engine was already destroyed by the time the check would be neccesary - even with very low loss rate, ie. 2%.
Yeah, given the low percentage of methanol, I can believe this. I'd definitely say GM-1 (nitrous) isn't corrosive though. Otherwise we'd have a lot of dead Honda Civics out there.
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Originally posted by GScholz
Alcohol will suck every last bit of humidity out of the air, and if left in the engine the water will corrode the metal. The alcohol itself is harmless.
Yeah you're prolly right, now that I think about it.
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Hmm, that's a little suprising. Do you know if that was from fouling/carbon build-up, or corrosive effects?
My understanding is that with the higher boost the engine ran hottter and the plugs would foul. Carbon would build up and thus no spark.
But regardless, if methanol goes into the compressor side of the SC, it goes into the cylinders, and it *does*get burned. I would imagine that the SC would have to be stainless or something to avoid corrosion. Maybe the rest of the intake and cylinders would not be affected as much if the methanol is a gas...but I doubt it
Well methanol evaporates faster then the water. Water wont accumulate due to the speed of SC and heat eng. You can get metal wet without corrosion as long as doednt stays in contact over time. Oil / lubricants protect most of the metal anyway.
The amount of heat and air will quickly evaporate the water.
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Originally posted by Wotan
My understanding is that with the higher boost the engine ran hotter and the plugs would foul. Carbon would build up and thus no spark.
Think you have that reversed. 'Cold' plugs tend to foul. That is why the P-51s would increase their revs and boost after cruising for awhile. An engine that is 'lugging' fouls with carbon.
At higher boost and revs, the plug gap would be eroded.
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Originally posted by Wotan
My understanding is that with the higher boost the engine ran hottter and the plugs would foul. Carbon would build up and thus no spark.
No, it's quite the opposite in cars...cold and rich causes carbon build-up. Heat can also damage plugs, the glazing and cracking etc...but I'd have thought the MW injection would mitigate that. That's why HoHun's comment on spark plugs surprised me.
Oh well... Minor point anyway.
Originally posted by Wotan
Well methanol evaporates faster then the water. Water wont accumulate due to the speed of SC and heat eng. You can get metal wet without corrosion as long as doednt stays in contact over time. Oil / lubricants protect most of the metal anyway.
The amount of heat and air will quickly evaporate the water.
Yup, understood.
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Hi Isegrim,
>Are you sure it worked that way ?
I just re-checked it, and it may be that I'm wrong. The diagram I remembered as showing the cut-out actually shows a solenoid-activated warning lamp for indicating low MW50 level.
Either there's another diagram with a cut-out I can't find right now, or I confused the warning lamp with a solenoid-activated cut-out.
Regards,
Henning (HoHun)
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Hi Phookat,
>Hmm, that's a little suprising. Do you know if that was from fouling/carbon build-up, or corrosive effects?
No idea. Maybe the electrodes burned away due to the higher temperatures in the combustion chamber?
Von Gersdorff et al. quote 15 - 30 h spark plug life, probably based on typical engine handling (opposed to pure MW50 operation).
Regards,
Henning (HoHun)
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Maybe the electrodes burned away due to the higher temperatures in the combustion chamber?
Thats what I meant.
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Originally posted by HoHun
Hi Isegrim,
>Are you sure it worked that way ?
I just re-checked it, and it may be that I'm wrong. The diagram I remembered as showing the cut-out actually shows a solenoid-activated warning lamp for indicating low MW50 level.
Either there's another diagram with a cut-out I can't find right now, or I confused the warning lamp with a solenoid-activated cut-out.
Regards,
Henning (HoHun)
On the right side of the lower panel there was two lamps and a switch. One lamp (red) was the 'low fuel' warning and the other was lamp (white) was for 'rear tank switch over'. The switch was fuel guage selector. Is this 'rear' tank the one under the pilot or the aux. tank?
@ Crumpp
Tech description 284, dated 28.11.44
"Based on the requirement to increase a/c range without degrading its aerodynamic efficiency, provision has been made for the mounting of a protected fuel tank within the rear fuselage. After Aug-Sept 1944 all A-8 a/c will be delivered with the fuel tank. If required, instead of the 115l fuel tank, an un-protected MW tank of either 115l or 140l capacity, or a GM1 tank of 85l capacity, can be installed. At the present time, however, it is planned that the standard A-8 will be produced only with the auxliary fuel tank".
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I always heard that Methanol had some bad aspect with corrosion.
But what exactly, I don't know.