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Octane rating - 5/6/2012 5:03:05 PM   
JohnDillworth


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Does anyone know the average octane ratings that were available to the Allies and Japan? I am under the impression that the IJN and IJA planes used gasoline with a significantly lower octane rating. If this is true were the planes designed with that octane rating in mind? Would they have performed better with better gas? If seems towards the end of the war the best planes were roughly equal (Frank & P-51). Would better gasoline have made the Frank a much better plane?

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RE: Octane rating - 5/6/2012 5:16:22 PM   
vettim89


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Waiting for it ................

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RE: Octane rating - 5/6/2012 7:20:39 PM   
JohnDillworth


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quote:

Waiting for it ................

OK, what did I do? I didn't cross Terminus did I? Which old timer? Did I compare specific aircraft? I swear I only meant to illustrate my question.....Oh great....There is a knock at the door.....hold on .......Who the hell is WITPAE Black Ops? Helppppppppppppppppp.................

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RE: Octane rating - 5/6/2012 7:25:39 PM   
Alfred

 

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American refineries were able to produce 100 octane fuel. Volume produced was sufficient to export it to allied countries. The Axis powers had to make do at best with 87/89 but that level was not always obtained, in the case of Japan dropping down to 81 octane in the second half of the war.

Not only could the American refineries get the high octane levels, they could do it more efficiently and at lower cost than the Axis.

To get the best out of the higher octane levels the engines would have needed to be specifically designed for it. Thus it is not simply a case of stating that the Frank with higher octane fuel would have flown better. Using is existing engine it would have seen an improvement in performance but the full benefit would be dependent on having the right engine for the fuel.

You know, those Americans were very gamey. The high octane was just one of several gamey actions which borked the war against the Axis. I'm often reminded about how most armchair generals just criticise the Italians for standardising with 840 hp FIAT engines for their airplanes without taking into account the real world constraints on their design options. Same issues often applied to the Japanese, which issues are never fully taken into account (in fact usually not at all) by people who argue how Japanese industry could have been reshaped to make better war materiel.

Alfred

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RE: Octane rating - 5/6/2012 7:45:17 PM   
Buckrock

 

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quote:

ORIGINAL: JohnDillworth

quote:

Waiting for it ................

OK, what did I do? I didn't cross Terminus did I? Which old timer? Did I compare specific aircraft? I swear I only meant to illustrate my question.....Oh great....There is a knock at the door.....hold on .......Who the hell is WITPAE Black Ops? Helppppppppppppppppp.................



I'd guess you must have inadvertently dropped your aviation fuel question into the embers of some old fire and now people are waiting to see what happens next.

Lucky you have that avatar.



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RE: Octane rating - 5/6/2012 7:55:59 PM   
Historiker


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quote:

ORIGINAL: vettim89

Waiting for it ................

I really don't have any intention to insult you and am really sorry, but isn't this almost trolling itself?
It annoys me every time, when those wise guys go into threads and don't contribute anything but "the trolls will come".

I know, calling someone a troll is one of the most harsh insults you can say in a forum, but again: Isn't that trolling by itself?



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RE: Octane rating - 5/6/2012 8:05:44 PM   
vettim89


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quote:

ORIGINAL: Historiker


quote:

ORIGINAL: vettim89

Waiting for it ................

I really don't have any intention to insult you and am really sorry, but isn't this almost trolling itself?
It annoys me every time, when those wise guys go into threads and don't contribute anything but "the trolls will come".

I know, calling someone a troll is one of the most harsh insults you can say in a forum, but again: Isn't that trolling by itself?




Ok, to be clear: often when avgas is discussed, I see it immediately morph into a discussion about how the George or Frank were actually the best fighters of WWII if the IJNAF/IJAAF had access to higher octane fuel. I was just ading that comment so I could claim clairvoyance when it happened. Sorry, did not mean to offend. I guess I was just trying to be too much of a smart alek

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RE: Octane rating - 5/6/2012 8:19:43 PM   
Historiker


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I didn't try to offend, either! You were only the unlucky one to hear my first expression of annoyance about this common habbit in this forum.

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RE: Octane rating - 5/6/2012 8:21:35 PM   
JohnDillworth


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A bit of background. I recently saw an article that claimed the use of American 100 octane fuel over the European 87 Octane allowed late model Spitfires to add 25-35 mph to their top speed depending on altitude thus winning the war. BS on the Spitfire even being important late in the war (could not escort bombers past the front yard)but I was curious as to the significant performance increase being reported. I presume the late model Spitfire was optimized for the 100 octane fuel because England was not refining too much of their own gas and basically using American supplies.

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RE: Octane rating - 5/6/2012 8:45:51 PM   
mike scholl 1

 

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quote:

ORIGINAL: Alfred

You know, those Americans were very gamey. The high octane was just one of several gamey actions which borked the war against the Axis. I'm often reminded about how most armchair generals just criticise the Italians for standardising with 840 hp FIAT engines for their airplanes without taking into account the real world constraints on their design options. Same issues often applied to the Japanese, which issues are never fully taken into account (in fact usually not at all) by people who argue how Japanese industry could have been reshaped to make better war materiel.

Alfred


Like the inability of the IJN and the IJA to agree on a common electrical voltage for their A/C..., meaning they had to maintain two seperate and parallel electrical componants industries. This situation would never have been allowed in the USA.

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RE: Octane rating - 5/6/2012 8:53:29 PM   
Erkki


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AFAIK the post war Allied(IIRC often with Japanese pilots though) performance tests performed using Allied fuels showed small but clear increase in performance, but still usually falling within 5%(performance variation typically expected between individual planes of same type) or so. I dont have a definitive source on hand now but digging the all knowing Internet for one shouldnt take long.

However as Japanese engines were most likely optimized to lower octanes(87, correct?), I believe having better fuels and engines made to use those fuels would have helped the Japanese fighters tested more.

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RE: Octane rating - 5/6/2012 10:04:15 PM   
JWE

 

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Ok, I'll bite. Yes, technically, higher octane gives better (faster) cylinder deflagration characterists and, thus, more horsepower. More horse power means better performance. How much? Dunno. But even 5% is better than none.

But ... There's always a butt, isn't there? ... it also increases cylinder temperature. So if the engine isn't designed for it, then ... Hundreds of books have hundreds of examples of Germans, Czechs, Poles, French, Italians, finding a crashed Allied plane and draining some gas from the wreck for their motorcars. Yeah, AvGas in a car. About an hour later, they had a smoking ruin of melted engine header. Gee, wonder why.

You need 100 octane fuel to design an engine that runs on 100 octane fuel. The egg definitely comes first in this case. You can't just gas up an engine, designed with a particular specific heat in mind, with the good stuff, without a certain degree of unanticipated consequences.

[ed] spelling

< Message edited by JWE -- 5/6/2012 10:05:20 PM >


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RE: Octane rating - 5/6/2012 10:24:37 PM   
HMSWarspite

 

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Close but not quite. Octane rating correlates with the fuel's ability to resist premature ignition, with increasing compression ratio. Low octane fuels cannot stand the temperature cause by higher compression, and will 'knock', or detonate before the spark plug fires. This results in loss of power, or engine damage (the charge gives the piston a filthy great kick down as it wants to continue moving up, not to mention possible surface damage due to the detonation wave)). Running a low compression engine on high octane fuel does nothing - you need a higher compression ratio (i.e. significant engine mods) to get anything out of it. On the other hand, for a given engine envelope, higher compression means more horsepower...

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RE: Octane rating - 5/6/2012 10:40:06 PM   
JWE

 

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Six of one, half dozen of t'other. I refer to it as better deflagration characteristics. But I defer to Mr Warspite.

[ed] The Winston Cup guys do tweak the ignition timing to accommodate the nifty, cool, additives they put in the gas. I think some of the cars are actually a degree ahead of TDC.

< Message edited by JWE -- 5/6/2012 11:15:25 PM >


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RE: Octane rating - 5/6/2012 11:37:13 PM   
wdolson

 

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The Reno Air Race guys tune their engines and make up their own mix of fuels for their planes. Some of the octane ratings are insanely high. Over 200 if I remember right. Some of the additives are so nasty the pit crews need to wear hazmat suits to handle the fuel.

The US made 100 and 140 octane fuel. 100 was the most commonly used, but some planes used 140. The B-29 is the only one I recall using 140 off the top of my head.

I know today they Europeans use a different calculation to come to octane ratings. A European 87 octane rating is closer to 91 by the American calculations. I ran into this with a friend who is a British immigrant and a motorhead. He was wondering why British cars performed better on lower octane fuels than the same car with the same engine in the US.

To elaborate on what Warspite said, the higher the octane rating, the slower burning the fuel is. A low octane fuel burns very quickly, so the cylinders basically get a quick hammer blow. High octane fuel burns slowly, so the cylinders get a smoother, longer push. That's why higher octane fuel gets more oomph out.

I know the Germans essentially had 87 and 91 octane during the war. I'm not sure what ratings the Japanese had. I wouldn't be surprised if they were going as low as 81 octane near the end. I know they were using turpentine for some fuel (probably a blend) at the end of the war.

Bill

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RE: Octane rating - 5/7/2012 12:38:36 AM   
JWE

 

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Looks like no one is gonna answer your question Mr Dillworth. Too bad. It was a good one.

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RE: Octane rating - 5/7/2012 1:46:19 AM   
JohnDillworth


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quote:

Looks like no one is gonna answer your question Mr Dillworth. Too bad. It was a good one.

I think I got most of an answer. Japanese planes used apx 87 Octane and Allied Planes used 100. Aircraft designed to use the 87 Octane will perform about 5% better (actually the 25 mph bump for spitfires is about 5% better)with 100 octane but the engines might not last as long. While the higher octane gas is "better" the 5% bump doesn't make much difference when you take into account other design decisions (guns vs. canons, armor vs. speed or range, training, maintenance). The only thing that still surprises me is that the Japanese were able to field excellent designs right until the end of the war. Considering their economy was no match for the US (or England or Germany for that matter)the fact that they could throw Georges or Franks into the mix at all is impressive. Thanks all

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RE: Octane rating - 5/7/2012 3:37:52 AM   
Knavey

 

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quote:

ORIGINAL: vettim89

Waiting for it ................


Yup...so am I. Heard a rumor...

Its supposed to be in the next patch. You will get to determine what octane your planes use and it will effect performance!



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RE: Octane rating - 5/7/2012 3:43:20 AM   
PaxMondo


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Bill's answer is about as good as you can get without going into some pretty deep science. 

This is all off the top of my head, so apologize for any inconsistencies.  Octane numbers are a bit arcane.  First off it is a scale, it doesn't relate to reality.  100 Octane meant 100% N-Octane back in 1910 or so, so going over a 100 is kinda hard to understand.  It is all about anti-knock.   Then there are two ways to calculate this, research and motor (RON and MON).  The europeans and americans use a differently weighted average of the two to establish their scale.  Then, and even more importantly, is that how octane was boosted in the 40's isn't how it is done today.  Then it was about alkylation and so the octane boost was coming from n-nonane and n-decane type fuels.  Now, it comes from FCC and that gives you alkylenes like benzene and toluene to boost the fuel.  The amounts required to boost are different and how the impact cylinder temps are different.  They also behave quite differently under temperature and pressure as their partial pressure are different.

But a lot of this isn't as important as it seems.  Once you bring methanol/water injection into play octane become less of a factor.  Still a factor, yes, but less than you think.  Let's look at the chemistry and the mechanics here.  Engines are all about gas expansion forcing a piston to move down a cylinder and turn a crankshaft.  Igniting gas is good for about a 38x factor of expansion, not counting temperature effects.  That's awful good.  Water though is good for 18x.  The nice thing about water is that it take heat to move to steam, and this is how water injection works.  You start with an engine that is running too hot, you inject water to cool it and you actually get MORE power from it as the water expands into steam.  This works really well with radial air cooled cylinders as they are all more or less the same.  With in line water engines, you always struggle to get in inside cylinders as opposed the outside (on a V8 this would be 2,3,6,7 against 1,4,5,8) to be the same temperature.  The downside to water is that it is incredibly corrosive and impurities are very dangerous to metals (like chlorine and sodium as in salt).  Now add on superchargers and/or turbochargers (twinchargers) and again you get more complex.  On top of all of this is that in the 40's all they had was analog controllers. 

By wars' end the germans (extensively) and the IJ (Dinah and some other models) were using water/methanol.  This, when coupled with charging systems, mitigates the octane issue.

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RE: Octane rating - 5/7/2012 3:54:10 AM   
witpqs

 

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quote:

ORIGINAL: PaxMondo

Bill's answer is about as good as you can get without going into some pretty deep science. 

This is all off the top of my head, so apologize for any inconsistencies.  Octane numbers are a bit arcane.  First off it is a scale, it doesn't relate to reality.  100 Octane meant 100% N-Octane back in 1910 or so, so going over a 100 is kinda hard to understand.  It is all about anti-knock.   Then there are two ways to calculate this, research and motor (RON and MON).  The europeans and americans use a differently weighted average of the two to establish their scale.  Then, and even more importantly, is that how octane was boosted in the 40's isn't how it is done today.  Then it was about alkylation and so the octane boost was coming from n-nonane and n-decane type fuels.  Now, it comes from FCC and that gives you alkylenes like benzene and toluene to boost the fuel.  The amounts required to boost are different and how the impact cylinder temps are different.  They also behave quite differently under temperature and pressure as their partial pressure are different.

But a lot of this isn't as important as it seems.  Once you bring methanol/water injection into play octane become less of a factor.  Still a factor, yes, but less than you think.  Let's look at the chemistry and the mechanics here.  Engines are all about gas expansion forcing a piston to move down a cylinder and turn a crankshaft.  Igniting gas is good for about a 38x factor of expansion, not counting temperature effects.  That's awful good.  Water though is good for 18x.  The nice thing about water is that it take heat to move to steam, and this is how water injection works.  You start with an engine that is running too hot, you inject water to cool it and you actually get MORE power from it as the water expands into steam.  This works really well with radial air cooled cylinders as they are all more or less the same.  With in line water engines, you always struggle to get in inside cylinders as opposed the outside (on a V8 this would be 2,3,6,7 against 1,4,5,8) to be the same temperature.  The downside to water is that it is incredibly corrosive and impurities are very dangerous to metals (like chlorine and sodium as in salt).  Now add on superchargers and/or turbochargers (twinchargers) and again you get more complex.  On top of all of this is that in the 40's all they had was analog controllers. 

By wars' end the germans (extensively) and the IJ (Dinah and some other models) were using water/methanol.  This, when coupled with charging systems, mitigates the octane issue.

When you say water/methanol, do you mean that the entire fuel was water/methanol, or that water/methanol was added to the avgas?

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RE: Octane rating - 5/7/2012 3:55:52 AM   
PaxMondo


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quote:

ORIGINAL: witpqs

quote:

ORIGINAL: PaxMondo

Bill's answer is about as good as you can get without going into some pretty deep science. 

This is all off the top of my head, so apologize for any inconsistencies.  Octane numbers are a bit arcane.  First off it is a scale, it doesn't relate to reality.  100 Octane meant 100% N-Octane back in 1910 or so, so going over a 100 is kinda hard to understand.  It is all about anti-knock.   Then there are two ways to calculate this, research and motor (RON and MON).  The europeans and americans use a differently weighted average of the two to establish their scale.  Then, and even more importantly, is that how octane was boosted in the 40's isn't how it is done today.  Then it was about alkylation and so the octane boost was coming from n-nonane and n-decane type fuels.  Now, it comes from FCC and that gives you alkylenes like benzene and toluene to boost the fuel.  The amounts required to boost are different and how the impact cylinder temps are different.  They also behave quite differently under temperature and pressure as their partial pressure are different.

But a lot of this isn't as important as it seems.  Once you bring methanol/water injection into play octane become less of a factor.  Still a factor, yes, but less than you think.  Let's look at the chemistry and the mechanics here.  Engines are all about gas expansion forcing a piston to move down a cylinder and turn a crankshaft.  Igniting gas is good for about a 38x factor of expansion, not counting temperature effects.  That's awful good.  Water though is good for 18x.  The nice thing about water is that it take heat to move to steam, and this is how water injection works.  You start with an engine that is running too hot, you inject water to cool it and you actually get MORE power from it as the water expands into steam.  This works really well with radial air cooled cylinders as they are all more or less the same.  With in line water engines, you always struggle to get in inside cylinders as opposed the outside (on a V8 this would be 2,3,6,7 against 1,4,5,8) to be the same temperature.  The downside to water is that it is incredibly corrosive and impurities are very dangerous to metals (like chlorine and sodium as in salt).  Now add on superchargers and/or turbochargers (twinchargers) and again you get more complex.  On top of all of this is that in the 40's all they had was analog controllers. 

By wars' end the germans (extensively) and the IJ (Dinah and some other models) were using water/methanol.  This, when coupled with charging systems, mitigates the octane issue.

When you say water/methanol, do you mean that the entire fuel was water/methanol, or that water/methanol was added to the avgas?

Injected separately from the avgas. 10 - 25% are typical proportions depending upon a host of things, including altitude.


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RE: Octane rating - 5/7/2012 9:23:55 AM   
Historiker


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100 Octane gas was introduced to German gas stations a few years ago. So far, we only had 92, 95 and 98 (IIRC, the use of "Normal", "Super", "Super+" is common, not the octane rating).
They tested the "V-Power" 100 Octane fuel in sport cars to find out whether the significantly higher price is justified. Their finding was, that in modern car engines - of course - the increase in performance is neglible.

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RE: Octane rating - 5/7/2012 1:02:19 PM   
JohnDillworth


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quote:

They tested the "V-Power" 100 Octane fuel in sport cars to find out whether the significantly higher price is justified. Their finding was, that in modern car engines - of course - the increase in performance is neglible.

I understand that formulations are different in the US depending on which part of the country you are in. Don't know the science but in the Mountain and Western states octane ratings are generally lower. Near racetracks you can but higher octanes. You can also buy 100 Octane in the Northest and Shell or Sunoco. They call it V-tech or something but it's a significant bump in price over the normal 93 octane premium so I never tried it. My car takes premium (93) since petrol is so expensive every other tank I but a medium grade (89). I don't hear any knocking, and the performance is about the same. I think I get slightly better mileage with the higher octane but I never really quantified it. The large majority of cars in the US have automatic transmissions. I have a 6 speed manual that allows you to either conserve gas (manual transmissions get about 3 MPG better mileage) or drive like a complete ass, so my mileage is more affected by mode than octane. Might be true of pilots too. I understand the range of the same aircraft could vary significantly by pilot. I believe Lindburg spent some time training pilots in how to conserve gas but I can't find the reference.

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RE: Octane rating - 5/7/2012 3:46:30 PM   
crsutton


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quote:

ORIGINAL: PaxMondo

Bill's answer is about as good as you can get without going into some pretty deep science. 

This is all off the top of my head, so apologize for any inconsistencies.  Octane numbers are a bit arcane.  First off it is a scale, it doesn't relate to reality.  100 Octane meant 100% N-Octane back in 1910 or so, so going over a 100 is kinda hard to understand.  It is all about anti-knock.   Then there are two ways to calculate this, research and motor (RON and MON).  The europeans and americans use a differently weighted average of the two to establish their scale.  Then, and even more importantly, is that how octane was boosted in the 40's isn't how it is done today.  Then it was about alkylation and so the octane boost was coming from n-nonane and n-decane type fuels.  Now, it comes from FCC and that gives you alkylenes like benzene and toluene to boost the fuel.  The amounts required to boost are different and how the impact cylinder temps are different.  They also behave quite differently under temperature and pressure as their partial pressure are different.

But a lot of this isn't as important as it seems.  Once you bring methanol/water injection into play octane become less of a factor.  Still a factor, yes, but less than you think.  Let's look at the chemistry and the mechanics here.  Engines are all about gas expansion forcing a piston to move down a cylinder and turn a crankshaft.  Igniting gas is good for about a 38x factor of expansion, not counting temperature effects.  That's awful good.  Water though is good for 18x.  The nice thing about water is that it take heat to move to steam, and this is how water injection works.  You start with an engine that is running too hot, you inject water to cool it and you actually get MORE power from it as the water expands into steam.  This works really well with radial air cooled cylinders as they are all more or less the same.  With in line water engines, you always struggle to get in inside cylinders as opposed the outside (on a V8 this would be 2,3,6,7 against 1,4,5,8) to be the same temperature.  The downside to water is that it is incredibly corrosive and impurities are very dangerous to metals (like chlorine and sodium as in salt).  Now add on superchargers and/or turbochargers (twinchargers) and again you get more complex.  On top of all of this is that in the 40's all they had was analog controllers. 

By wars' end the germans (extensively) and the IJ (Dinah and some other models) were using water/methanol.  This, when coupled with charging systems, mitigates the octane issue.



Now head hurt very bad.....

But it was not just octane was it? If I recall, Japanese refining methods left a lot of impurities in their fuel as well. This would serve to degrade performance over time. And time in service. A new engine out of the box would work a lot better than one that had some hours operating on less than ideal fuel. So any plane with a new engine would be different from an engine that had 50 hours of time using a poor quality fuel. Too many factors really. All things considered, an Allied engine with a little time on it was probably in much better shape than a Japanese engine with the same amount of time. Then there is lube oil. Allies probably had better qualty in this as well but I am just spectulating.

< Message edited by crsutton -- 5/7/2012 3:54:57 PM >


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Post #: 24
RE: Octane rating - 5/7/2012 4:25:34 PM   
JohnDillworth


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quote:

Allies probably had better qualty in this as well but I am just speculating.
It goes to maintenance in general. The US was just better at providing the support and structure for maintaining complex machines. I've read that the US had a ton of kids that were used to tinkering with farm machinery when they were called up. Internal combustion engines were not unusual for them so the transition into a more complex engine maintenance was not that far of a leap. It was probably true for all engineering disciplines from aircraft mechanic to SeaBee. Education was highly regarded at the time and not at the expense of blue collar skills. This may have also been true in Germany, Australia and England but perhaps not so much in Japan. No doubt Japan had some excellent mechanics with the very best being on the CV's that were the equal of the Allies, after that it may have dropped off. Combine that with a disrupted supply chain, inter-service stupidity, sometimes poor fuel, some malnutrition and a fundamental disregard for human lives and you have an increasingly separate situation

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Post #: 25
RE: Octane rating - 5/7/2012 5:47:47 PM   
Sardaukar


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IIRC, higher octane fuel really helped with high-altitude fighter missions in Europe (planes like P-47 and P-51). Combat flying is lot more about raw power in higher altitudes where German planes were not that stellar (Ok, maybe Ta-152).

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Post #: 26
RE: Octane rating - 5/7/2012 7:28:08 PM   
Gridley380


Posts: 245
Joined: 12/20/2011
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quote:

ORIGINAL: JohnDillworth

It goes to maintenance in general. The US was just better at providing the support and structure for maintaining complex machines. I've read that the US had a ton of kids that were used to tinkering with farm machinery when they were called up. Internal combustion engines were not unusual for them so the transition into a more complex engine maintenance was not that far of a leap. It was probably true for all engineering disciplines from aircraft mechanic to SeaBee. Education was highly regarded at the time and not at the expense of blue collar skills. This may have also been true in Germany, Australia and England but perhaps not so much in Japan. No doubt Japan had some excellent mechanics with the very best being on the CV's that were the equal of the Allies, after that it may have dropped off. Combine that with a disrupted supply chain, inter-service stupidity, sometimes poor fuel, some malnutrition and a fundamental disregard for human lives and you have an increasingly separate situation


All true. The Japanese were able to mitigate this early on by providing lavish training for a very small force. When they tried to rapidly expand their quality dropped sharply.

(in reply to JohnDillworth)
Post #: 27
RE: Octane rating - 5/7/2012 8:29:54 PM   
JWE

 

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Well, here's a good one for our technical experts to comment on in this regard.

Forget who it was, but somebody taught the boys at Taiwan to fly reeeally leeean so they could get to PI and still have a couple minutes of combat power. As I recall, they were at cylinder temp red-line tho whole way. Maybe one of our experts could comment on how this was done. Maybe one of our experts could comment on what would have happened with a plane designed for a higher octane fuel and a higher head temperature. Could our planes have gone lean and gotten that much better range characteristics?

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Post #: 28
RE: Octane rating - 5/7/2012 9:02:27 PM   
crsutton


Posts: 7109
Joined: 12/6/2002
From: Maryland
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quote:

ORIGINAL: Gridley380


quote:

ORIGINAL: JohnDillworth

It goes to maintenance in general. The US was just better at providing the support and structure for maintaining complex machines. I've read that the US had a ton of kids that were used to tinkering with farm machinery when they were called up. Internal combustion engines were not unusual for them so the transition into a more complex engine maintenance was not that far of a leap. It was probably true for all engineering disciplines from aircraft mechanic to SeaBee. Education was highly regarded at the time and not at the expense of blue collar skills. This may have also been true in Germany, Australia and England but perhaps not so much in Japan. No doubt Japan had some excellent mechanics with the very best being on the CV's that were the equal of the Allies, after that it may have dropped off. Combine that with a disrupted supply chain, inter-service stupidity, sometimes poor fuel, some malnutrition and a fundamental disregard for human lives and you have an increasingly separate situation


All true. The Japanese were able to mitigate this early on by providing lavish training for a very small force. When they tried to rapidly expand their quality dropped sharply.



Well, this plus the fact that only a small proportion of the Japanese population had been educated up to the high school level. Many rural Japanese's (the majority) education did not go beyond grammar school level. You can make a good soldier out of this material but not necessarily a good mechanic.

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Post #: 29
RE: Octane rating - 5/7/2012 9:03:15 PM   
inqistor


Posts: 1332
Joined: 5/12/2010
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quote:

ORIGINAL: JohnDillworth

Does anyone know the average octane ratings that were available to the Allies and Japan?

"Allies" is WIDE expression. Russian military policy, since WWII is to allow vehicles to operate on captured fuel, so their planes can operate on pretty crappy AVGAS. Now, what was actually used by China, while they operated planes from both US, and Russia?

Also - some interesting facts:
Germany used Synthetic Fuel. The further into war, the more % of total usage was made from coal. And it produced BETTER quality AVGAS, than oil.
As for Japan:
Take a look at my old topic about D3A2 range. Here is exact cite from this page:
quote:

This is from Aircraft in Profile #240 "Aichi D3A ('Val') & Yokosuka D4Y ('Judy') Carrier Bombers of the IJNAF (M. C. Richards and Donald S. Smith):
Fuel Capacity of D3A
"Internal 1,079 liters (235 Imperial gallons) in five unprotected tanks; two in each wing, one under pilot's seat, all containing 92 octane petrol. In starboard wing root, a small fuel tank (100 octane) for take of; 58 liter (25.8 Imperial gal.). One 60 liter (13.2 Imp.gal.) oil tank behind the engine."

Was 92 Octane standard for Japan, or only used on Carriers?

(in reply to JohnDillworth)
Post #: 30
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