Aces High Bulletin Board
General Forums => Aircraft and Vehicles => Topic started by: Keiler on August 03, 2005, 04:25:49 AM
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How come the AH2 SpitMk1A has such a high climbrate? The maximum values I find on the net (google) are 2500fpm, and most float around at 2100-2200fpm...
Any explenation to that? Engine variations?
Thanks!
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http://www.spitfireperformance.com/spit1.html
http://www.spitfireperformance.com/n3171.html
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Going to be even better when the re-model changes its boost from the current 6lbs to the more common 12lbs.
Incidently this use of the 100 grade fuel also adds around 30mph to top speed.
Should make BoB scenarios more 'interesting'.
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Thanks ramzey! :aok
[edit]
Kev, was this 12lbs boost common?
Guess those accounts by british RAF pilots the "Emil climbed like it took an elevator, while we took the stairs" was from 6lbs plus fixed prop or 2 staged...
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100 octane was common during the battle
btw, where do Brits get their 100 octane fuel anyway?
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Originally posted by Keiler
Thanks ramzey! :aok
[edit]
Kev, was this 12lbs boost common?
Guess those accounts by british RAF pilots the "Emil climbed like it took an elevator, while we took the stairs" was from 6lbs plus fixed prop or 2 staged...
that quote is obviously bs as british do not call it an 'elevator'
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I quoted it on top of my head, as I read the passus in a german article, where they had interviewed british and german pilots of BoB.
;)
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Yup 100 grade fuel was very common.
After Dunkirk and the Battle of France Spit I's were converted starting in March 1940, the huge stockpile they had was released to the squadrons in May.
Will make a big difference to the next BoB scenario-
With 100 grade fuel - Spit I max speed up by over 30mph, plus it will have 12lbs boost instead of our current 6lbs.
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rgr thanks Kev :)
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Will the spit1 be faster than the 109 and 110?
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Certain alts it will be faster than the 109. They were pretty evenly matched, 109 faster at certain alts, Spit at certain alts.
In fact that evenly matched its probably one of the few battles in history where the men involved rather than the machine decided the outcome.
The 110 commonly used in the BoB I believe will still be faster. Unless we get the earlier BoB version before the next scenario.
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The AH spit1 is already faster than the 109. If the spit1 gains 30 mph it will be faster than all other early war planes including the 110. If that's the case then it is complete BS.
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lol give the spit1 30mph more and it's faster than the spit5 and 109F. I think you're full of it.
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Read this
http://www.mikekemble.com/ww2/spitfire.html
Depending on where you find the figures it was an approx speed increase of 25-34mph depending on alt using 100 grade fuel. I just used an average figure.
And this
http://www.spitfiresociety.demon.co.uk/spitdev.htm
And this
http://www.deltaweb.co.uk/spitfire/survival.htm
Above 20,000ft the 109 was marginally faster.
Finally official RAF site http://www.raf.mod.uk/bob1940/index.html
Take a Spit 1 up and try chasing the 110-G2 which is used in the BoB scenario, try to follow it ina dive also.
Now whos full of it?
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You are. 30 mph more than what? the AH spit1 already does more than 360 mph while the 109 can't even reach 350. Above 15k the spit is completely dominant.
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30mph average increase using 100 grade fuel and a 12lbs boost over an 87 grade fuel one.
Our current Spit 1 is based on a 1939/early 1940 87 grade fuel 6lbs boost one.
Bear in mind the 109s are being overhauled aslo and I would expect the differences to be closer to historic figures as compared to our current performance.
Will try and find a Mk I speed chart with 100 fuel.
You'll be hard pressed catching a 110-G2 above 20k in a Spit 1, and believe me in the BoB scenario they arent coming over the channel at sea level.
The 109 and Spit 1 are fairly even at 15k speed wise, over 20k the edge goes to the 109 (marginally).
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Originally posted by Kev367th
Certain alts it will be faster than the 109. They were pretty evenly matched, 109 faster at certain alts, Spit at certain alts.
Originally posted by Kev367th
The 110 commonly used in the BoB I believe will still be faster. Unless we get the earlier BoB version before the next scenario.
That is not compatible with this:
Originally posted by Kev367th
30mph average increase using 100 grade fuel and a 12lbs boost over an 87 grade fuel one.
If the spit1 gains 30mph it will no longer (in fact it already isn't) be "pretty evenly matched", it would be grossly superior.
Originally posted by Kev367th
Take a Spit 1 up and try chasing the 110-G2 which is used in the BoB scenario, try to follow it ina dive also.
Now whos full of it?
The 110-G2 is a 1943 model fer christ sake. The BoB version is the 110-C4. You have no idea what you're talking about, have you?
Originally posted by Kev367th
30mph average increase using 100 grade fuel and a 12lbs boost over an 87 grade fuel one.
I think you already have the performance of a 12lbs boost spit1. In either case your +30mph is a pipedream because it would make the spit1 outperform later model spits and many mid-to-late war planes, which is completely unrealistic.
Yes you are full of it.
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Originally posted by Kev367th
You'll be hard pressed catching a 110-G2 above 20k in a Spit 1, and believe me in the BoB scenario they arent coming over the channel at sea level.
See earlier comment on you not knowing what you're talking about.
Originally posted by Kev367th
The 109 and Spit 1 are fairly even at 15k speed wise, as you go higher the edge goes more and more to the 109.
Not in AH. The spit1 is completely dominant above 15k. At 15k the 109 starts to lose power and speed with altitude. The spit1 continues to gain speed up till about 20k.
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Spit 1 (using +12 boost/100 octane fuel used during the Battle of Britain) is actually faster than 109E at all alts
http://www.spitfireperformance.com/spit1vrs109e.html
and FalconSix... No trolling allowed
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Ok got the two 110 mixed up, try taking up a C4 to its best alt 23k ish at which it does around 350mph.
Now chase it with a Spit 1, they are about the same at that alt, BUT the chances are you won't be at 23k, you'll still be climbing in the scenario.
Now as for the 87/100 debate.
As far as I am aware and no-one has said anything to the contrary our current Spit 1 is based on a 87 grade/6lbs boost one.
The usage of 100 grade fuel boosted the performance of the Spits as shown in the links I posted.
Thanks 1K3 I was trying to find that, gotta admit I never realised that it totally made the Spit faster at all alts, was going off what I remember from last years BoB, we couldn't catch the 110s.
Like I said will make the next BoB scenario very interesting indeed, depending on what they do with the 109E-4.
Apologies for the inacurrate post, memory often misleads,and its late.
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Originally posted by 1K3
Spit 1 (using +12 boost/100 octane fuel used during the Battle of Britain) is actually faster than 109E at all alts
http://www.spitfireperformance.com/spit1vrs109e.html
and FalconSix... No trolling allowed
The AH spit1 IS FASTER AT ALL ALTS. It's even faster than in your charts. The AH spit1 is a 360+mph plane!
(http://www.hitechcreations.com/ahhelp/models/charts/spit1speed.gif)
(http://www.hitechcreations.com/ahhelp/models/charts/109e4speed.gif)
I'm not trolling. If anyone's trolling it must be kev!
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1K3 have you got the link to that other site that does the performance of AH planes, I tend to find it a little more accurate?
I don't think I've ever gotten an AH1 Spit 1 to 360, unless its straight down missing a tail.
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More accurate than HTC's own charts?
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Originally posted by FalconSix
The AH spit1 IS FASTER AT ALL ALTS. It's even faster than in your chrats. The AH spit1 is a 360+mph plane!
nope
spit 1 has max speed of 355mph at 17,800 feet
i tested this a looooooooong time ago.
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A lot of stuff are theoretical limits, you dont think they acually flew a plane at all those diff alts to get the charts? Easiest way to find out is go offline and take a Spit 1 up see what happens. Theory and practice tend to be two different animals.
If you look at 1K3 charts - AS I SAID the speed increase varied on altitude, above 17k or so 100 fuel makes no difference.
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Originally posted by 1K3
nope
spit 1 has max speed of 355mph at 17,800 feet
i tested this a looooooooong time ago.
Ok, and according to the chart you linked to it shouldn't do more than 354mph on 100 octane... and you guys want to add 30 mph to that?
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Originally posted by Kev367th
Makes you wonder 1K3 is our current Spit 1 a 100 grade fuel beast limited to 6lbs boost?
That doesn't make sense at all. Increasing octane without increasing boost yields nothing. Higher octane rating doesn't add power, only allows for more boost.
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Read the chart again - over 17k 100 fuel makes no difference.
Under that with boost on it makes all the difference, as I said from 25-34mph.
I see its where I said top speed, I should have been more clearer, what I should have said is top speed at lower alts, my apologies.
i.e It can reach its 350+ at lower alts with boost on.
That actually makes HT charts look fairly accurate, seems to be 350-360 ish, although I think the WEP curve is off a little.
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Really? The Spit1 was faster than the Spit5 on the deck?
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Never said on the deck, geez look at the chart 1K3 posted, 100 fuel with 12lbs boost allowed the Spit 1 to reach 350 or there abouts at 11k ish, assuming the chart is accurate and I am reading it correctly.
Mk V stuff here, draw your own conclusions
http://www.spitfireperformance.com/spitv.html
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It also says 310 mph on the deck. That's faster than the Spit5.
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Could part of be in AH you can only run WEP 5 mins in Spits, where actually they would run it for much longer periods?
This possibly throw up discrepencies?
Unfortuneately spitfireperformance.com I can't find a performance chart for a Mk I @ 100/12lbs.
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I have no idea.
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Originally posted by FalconSix
It also says 310 mph on the deck. That's faster than the Spit5.
its not faster at deck than our current spit 5
the current spit 5 uses higher boost (+16)
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I suppose its quite possble the early Mk V's being heavier even with a more powerful motor werent that much faster.
eg here lists a Mk Vb (Merlin 45) were top speed is 374 at 19k.
http://www.spitfireperformance.com/spitv.html
Plus - You have to remember that different variants of the Merlin were designed to produce max power at different alt ranges. Hence the later LF ,F ,HF designations of Spits from the V onwards, HF only on later models.
i.e. a Merlin 55M (low alt) version produced most power down low therefore max speed was achieved at lower altitudes.
Also add to that its 'easier' to achieve a higher speed at alt due to less air, if you look at most of the later Merlins the lower alt versions generally produced more HP than the high alt versions.
eg (first Mk V's)
Merlin 45 - F Vb , F Vc 1470HP
Merlin 45M - LF Vb, LF Vc 1585HP
good eg is spit IX
LF had 1580HP Merlin 66
F had 1565HP Merlin 61
HF had 1475HP Merlin 70
Maybe its possible the Spit 1 at lower alts with WEP on is faster or as fast OTD as the F Vb/c that were fitted with a Merlin 45 designed to produce max speed at a higher alt?
So I guess it depends which Mk V you are comparing it to.
Dunno just throwing out ideas.
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Spitfire I with Merlin III at +6lbs has 1030hp
Spitfire I with Merlin III at +12lbs has 1300hp
Spitfire V with Merlin 45 at +9lbs has 1185hp
Spitfire V with Merlin 45 at +16lbs has 1470hp
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100 octane fuel and +12 lbs was not common in service until the Battle of Britiain already ended in october 1940. The RAF could not convert all fighters to it until November, 1940.
Without 100 octane fuel, +12 lbs boost was not possible.
There are claims made by some that 100 octane fuel was throughlty, and without exception introduced to all and every fighter as early as the spring of 1940, but unfortunately there`s no evidence behind the claim, and it appears to be more like the wet dream of some fanboys.
The following is from documents from the Australian archives :
"The first bulk shipment of 100 octane fuel had arrived in Britain in June 1939 from the Esso refinery in Aruba. This and subsequent tanker shipments from Aruba, Curacao and the USA were stockpiled while the RAF continued to operate on 87 octane petrol. Having secured what were considered reasonably sufficient quantities of 100 octane, Fighter Command began converting its engines to this standard in March 1940, allowing boost (manifold) pressures to be raised without the risk of detonation in the cylinders.
By the time of the invasion of the Low Countries by Germany in May 1940 the RAF had converted approximately 25 % of it's total fighter force to 100 octane fuel use. The subsequent escalation in air activity and demands placed upon Fighter Command over the next two months put great strain on both the 100 octane fuel stockpiles and aircraft modified to use the fuel. Against the backdrop of total war the RAF found that it's reserves of 100 octane fuel was well below the level considered necessary for widespread use, for any sustained length of time.
Two actions were immediately undertaken by the British War Cabinet in May to resolve the looming crisis. Firstly 87 octane fuel was deemed the primary fuel source to be used until further supplies could be discovered and delivered in sufficient quantities to allow the Merlin conversions to again take place. Those existing fighters already so converted (approximately 125) would continue to use what supplies of 100 octane were available, but all other fighters that had not been modified to continue with the use of 87 octane (of which there was more than adequate supply). The second action was for the British Government to contract the Shell Oil Refining Company to assist the British-controlled Iraqi Petroleum Company at Kirkuk to produce 100 octane fuel. This arrangement proved quite successful as production was quickly converted to 100 octane fuel.
The first Middle East shipment of 100 octane fuel arrived in Portsmouth on 12th August, with a further two deliveries in September and four in October. Although too late to allow widespread conversion for the use of the fuel the deliveries did ensure that from this point on Britain would not be lacking in 100 octane fuel levels. With the newfound supply RAF Fighter Command again embarked upon a Merlin II and III conversion to 100 octane use from late September, finally achieving 100% conversion of it's fighter force by the end of November in 1940.
http://www.allaboutwarfare.com/forums/index.php?showtopic=230&hl=
I came across it when I was in fact researching another subject (Dutch East Indies Fuel levels prior to the Japanese Invasion) at the Australian War Memorial Archives.
It's from a document, copied to the Australian Military Commission in England in February 1941, by Roll Royce to Lord Beaverbrook outlining past, current and proposed changes to the Merlin; and factors that affect it's performance.
It was quite an interesting paper actually, even though i found it to be a very dry subject.
It was a collection of lose-leaf typed pages, included as an addendum in a report titled Fuel Supplies to The British Empire And It's Commonwealth; Outlook, Ramifications and Projections For The Prosecution Of The War.
The reason why it is included amongst AWM papers is because the Australian Government at that time was protesting vigoriously about the continued supply of lower grade 87 octane fuel when it too wanted 100 octane for the RAAF.
I believe that McFarland, Pugh, Hart, Perret, Lumsden and even Churchill have all quoted parts from the report. "
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Originally posted by Kurfürst
it appears to be more like the wet dream of some fanboys.
My my Barbi throwing the insults around, again.
Nice of you to include the link so people can see your selective quote.
For those that can't read the thread.
This is also what the poster said:
question
"or were the British deceiving to the Australians?"
I wouldn't be surprised. The British did quite a bit of that during both World Wars.
more from the link
4./ 11/7/40 RAF had 343,000 tons of 100 octane in store.
5./ 10/10/40 RAF had 424,000 tons of 100 octane in store. After 22,000 tons issued during the B of B.
1 ton = 2240lb, 1 barrel = 35gal.
Other can do the math but it is a very large number of Spit sorties.
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The following is from documents from the Australian archives :
Just to make it clear, what Isegrim/Kurfurst is claiming comes from the Australian archives actually comes from someone called "PipsPriller" on another forum. And he's not quoting from the Australian archives, he's giving his interpretation of what he read some time before. He couldn't actually provide any of the material, and still hasn't, a year or more later.
What the actual British archives say is that as of November 1940, the reserves of 100 octane fuel in the UK stand at 500,000 tons. They also give actual British consumption of 100/130 fuel as an average of 2,500 tons per week in 1940.
In 1940, the fuel capacity of the Spitfire was 85 gallons, or 612 lbs. No drop tanks were in use.
If each Spitfire used an entire tank full of fuel (ie it landed empty), you'd get 3.6 sorties per ton. An average of 2,500 tons per week would allow for over 9,000 Spitfire and Hurricane sorties per week, if all the fuel went to Fighter Command.
In actual fact, during the BoB Fighter Command averaged about 4,000 sorties per week, for the rest of the year they averaged much less.
Wood and Dempster, The Narrow Margin, says Fighter Command used 22,000 tons of 100 octane fuel 1oth July - 10th October, which is enough for 6,000 sorties per week, in actual fact FC flew about 4,000 operational sorties per week, so there was plenty left over for wastage and testing (note the 22,000 tons figure is for Fighter Command, not the RAF as a whole, or British industry)
So, against "Pips Priller's" interpretation of what he remembers from the Australian archives about British fuel use, we have actual fuel use from the British archives, which shows far more 100 octane was used than was sufficient for fighter command.
I suspect Pips Priller is confused between Fighter Command and the whole RAF, with parts of the RAF not switching over to 100 octane fuel, whereas the whole of Fighter Command did (naturally enough, FC was the priority in 1940)
Mike Williams has evidence for 18 Spitfire squadrons during the BoB using 100 octane (there were 19 Spitfire squadrons in the BoB).
All the evidence supports 100 octane being the standard fuel for FC during the BoB. "Pips Priller's" claims on another board contradict it.
I know which I'll trust.
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That`s what I was referring to. Some fanboys are ignoring the evidence foubd by Pip, and try to dismiss it by any means.
Tough part is, guys like Mike Williams who is quite well known for manipulating evidence (see the link in my sig) claims that 100 octane was standard during the whole battle in 100% use all the time, but they cannot provide any evidence to it at all.
All they would have to post is the amount 87 octane and 100 octane fuel consumed by Fighter Command; they were in the archives and found fuel docs, but are unwilling to post such information, obvious why.
As for Nashwan, aka Hop, aka Lord Haw-Haw the various nick he used on other boards, the same story. No evidence, but would like to dismiss Pips`s finding from the Australian archieves. He isn`t thinks twice when it comes being liar, or to come up with NAZI accusations instead of real arguements, but that`s another matter. In short, he is a moral piece of **** I`d not even touch with a stick.
Now this guys claims Wood and Dampster says 22 000 tons would be enough for 6000 sorties a week - bullocks as WandD notes 22000 tons being used up, but doesn`t say anything about how much it was good for.
Which brings a question how much 22000 tons were worth. In 1944, the 8th FC used up 20 000 tons of fighter fuel a SINGLE month.
The RAF used up 12 000 tons, and it was enough for 10 000 sorites.
Yet we are to believe that by some miracle, 1940, 2/3s of this amount was enough for not ONE month but FOUR...
Moreover both posters are selective qouting the thread, Neil Stirling`s posts to be precise who denies the gradual standardization of 100 octane... but his posts also contained the list of the 100 octane reserves that stood at 500 000 tons in Nov 1940, which the British estimated to be enough for 80 weeks at present consumption.
This gives the fuel consumption in early Nov 1940 as 500 000 t/ 80 weeks = 6250 tons per week. We also know that by that time, most of Fighter Command was running on 100 octane (funny these guys don`t debate this from the Australian Archives, just the parts they don`t like).
Obviously, if 22 000 tons was suplied during July-October (3 months or 12 weeks), and 6250 tons was consumed every week by the time FC completely switched over... well 22 000 t supplied / 6250 tperweek = 3.5 weeks of consumption provided every fighter is supplied with 100 octane fuel.
In other words, the 22 000 months supplied during the Battle was enough for less than a month (let`s remember the 8th FC and the ADGB consumed 32 000 tons in a single month in mid1944)...
... or for all 3 months from July to October, the period WandD gives, if on avarage only 1/3 of the fighters were using the fuel.
It is more likely of course, and the normal go of things, that the fuel was little used - being on short supply - initially, then more and more was issued.
Moroever it agrees with the 1941 British records found in Australian archives, which state 25% of the fighters using the stuff shortly before BoB, in May 1940. It probably grow 50%, then 75% and finally to 100% by the end of November. On avarage, it was probably around 35% as the sources notes, given that the first abroad shipments only arrived late in the Battle, in August and September.
To summerize, a wartime British report on fuel situation from 1941 notes that around 125 fighter of the FC had 100 octane before the battle, and they gradually switched over by November.
It makes sense, it`s supported by WandD figures of 100 octane usage in the Battle compared to avarage British fuel consumption in November.
Some revisionist like Mike Williams and Neil Stirling, both grown quite infamous lately for manipulating evindece and having an obvious pro-RAF bias, challange these facts, and claim something that never happens in real life like sudden, immidiate and complete changeover in a single month.
They are unable to show fuel deliveries, They are unable/unwilling to show the relative fuel usage of 87/100 octane fuel, they are unable to show serious evidence like how much fuel was issued in July, August, September or October.
Moreover we see that they cannot give reasonable answers to why some docoments disagrees with their claims, and merely dismiss the counter-evidence in kneejerk reaction. When asked to provide evidence to their claims they don`t answer but disappear.
Personally, I`d like to see what real evidence they can offer, such would be fuel deliveries or the unit`s Operational records noting the use of +12lbs. But no such evidence seem to exists on the large scale, which hardly makes the whole 100octane claim series more than the wishful wet dreams of a handful of agenda driven nationalists.
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Originally posted by 1K3
its not faster at deck than our current spit 5
the current spit 5 uses higher boost (+16)
Current SpitV at +16 boost flies 290 without wep and 309 with wep. on the deck. Full out.
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Well was wondering where Kurfurst had got to, he's back with a vengence huh?
March 1940 Spits conversion to 100 grade began
May 1940 Churchill comes to power, stockpile of 100 grade fuel released to squadrons (co-incidence, huh).
As usual you hype everytihng, no-one claimed EVERY fighter used 100 grade, but that by the BoB enough had been converted to make it the most common fuel used by Spits.
They started conversion by in March and you said completed in November.
OK thats 8 months so assuming a steady conversion rate by the Start of July 50% would be on 100 grade. Thats assuming a steady conversion rate, personally I would think they would have converted faster near the beginning with the upcoming battle that was obviously coming, and slowed down Sept onwards after it had fininshed.
This would also mean assuming steady conversions by Sept the end of the battle 75% would have been on 100 grade.
Isn't it nice when someone takes your own figures and turns them back on you. You said completed Nov, no-one else did, I know they started conversions in March.
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So Barbi brings up 100 fuel deliveries. Yet he absolutly ignores, fails and is unwilling to provide any documention for C3 fuel deliveries to 109K-4 units that required it for 1.98.
Strange that Barbi ignores what Pips said about the Aussies being deceived by the Brits with regards to 100 fuel which casts doubt on the document. Naturally he picks what suits your agenda and ignores that which does not.
The RAF used up 12 000 tons, and it was enough for 10 000 sorites.
Crips Barbi, one Lancaster carried 2154gal of fuel. The Halifax carried a simular fuel load. A Mosquito carried 453 gal. Would not be hard for these 3 bombers to burn most of that 12,000t. The a/c of 1944 were more thirsty than those of 1940. And you yap about others being deceptive and manipulating data.
Barbi, it is not that were not enough 100 fuel but the conversion of a/c to take the 100 fuel. Any replacement a/c would be so converted. So if we are to believe your claim of low TBO for the Merlin it would take no time to convert. Also remember that 11 Group was the principle opponent to the LW and would get prioity on 100 fuel Spits.
22,000t for 12 weeks is 1833 t/wk. That is enough for 5990 (only 10 short of 6000 :eek: ) Spit sorties, so I don't know what you are going on about. Nashwan already stated the average was 4000 sortie/wk.
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As for Nashwan, aka Hop, aka Lord Haw-Haw the various nick he used on other boards, the same story. No evidence, but would like to dismiss Pips`s finding from the Australian archieves. He isn`t thinks twice when it comes being liar, or to come up with NAZI accusations instead of real arguements, but that`s another matter. In short, he is a moral piece of **** I`d not even touch with a stick.
Don't think I've ever gone by the name Lord Haw Haw, I think that would suit your style better. I post on forums as Hop or Nashwan, and have never made any secret of the fact I use both names, and in fact point it out to people if they know me by a different name from elsewhere.
Now this guys claims Wood and Dampster says 22 000 tons would be enough for 6000 sorties a week - bullocks as WandD notes 22000 tons being used up, but doesn`t say anything about how much it was good for.
No, I said Wood and Dempster said 22,000 used, I didn't say they gave the figure for how many sorties. English isn't your first languauge so I'll forgive you for this.
Which brings a question how much 22000 tons were worth. In 1944, the 8th FC used up 20 000 tons of fighter fuel a SINGLE month.
How much fuel did a Mustang or Thunderbolt carry compared to a Spitfire I or Hurricane I? And that ignores the numbers.
FC had about 600 - 700 fighters operational, the 8th would fly far more sorties than that in a day, sometimes that many on a single raid.
Yet we are to believe that by some miracle, 1940, 2/3s of this amount was enough for not ONE month but FOUR...
When the Spitfire and Hurricanes carry less than a quarter as much fuel, and there are far fewer of them, why not? (from memory the P-47 with tanks could carry as much as six times the fuel of a 1940 Spitfire or Hurricane)
And it's three months, 10th July to 10th October, that's 3 months by our calendar.
Moreover both posters are selective qouting the thread, Neil Stirling`s posts to be precise who denies the gradual standardization of 100 octane... but his posts also contained the list of the 100 octane reserves that stood at 500 000 tons in Nov 1940, which the British estimated to be enough for 80 weeks at present consumption.
No, not ignoring it at all, Isegrim.
This gives the fuel consumption in early Nov 1940 as 500 000 t/ 80 weeks = 6250 tons per week.
Right. That probably fits with the average of 2,500 tons a month for the whole of 1940, consumption would have increased towards the end of the year because of the gradual switch over throughout the RAF.
We also know that by that time, most of Fighter Command was running on 100 octane (funny these guys don`t debate this from the Australian Archives, just the parts they don`t like).
Well all, or almost all, I think.
Obviously, if 22 000 tons was suplied during July-October (3 months or 12 weeks), and 6250 tons was consumed every week by the time FC completely switched over... well 22 000 t supplied / 6250 tperweek = 3.5 weeks of consumption provided every fighter is supplied with 100 octane fuel.
In other words, the 22 000 months supplied during the Battle was enough for less than a month (let`s remember the 8th FC and the ADGB consumed 32 000 tons in a single month in mid1944)...
Slight logical flaw here. You are ASSuming 6250 tons a week in November 1940 was just for Fighter Command. Do you have any evidence to support that? The report certainly doesn't say it.
Of course, the more likely conclusion is that Fighter Command was burning about 1 - 2,000 tons a week, and the rest of the RAF, as well as the aircraft and engine makers, were burning the rest.
Moroever it agrees with the 1941 British records found in Australian archives, which state 25% of the fighters using the stuff shortly before BoB,
Do the records show that? I don't think Pips has ever provided them, has he?
I suspect the records show 25% of the RAF burning 100 octane, not 25% of fighter command.
It probably grow 50%, then 75% and finally to 100% by the end of November. On avarage, it was probably around 35% as the sources notes, given that the first abroad shipments only arrived late in the Battle, in August and September.
The problem with this is the Wood and Dempster figure. If 22,000 tons for fighter command was only powering a third of their sorties for the period, then you get about 220,000 FC sorties in 13 weeks during the BoB, or about 17,000 a week.
But the records don't show anything like that number of sorties, in fact they show about 4,000 a week.
To summerize, a wartime British report on fuel situation from 1941 notes that around 125 fighter of the FC had 100 octane before the battle,
No, to summarize an Australian claims that an Australian report says that. British reports say an average of 2,500 tons used a week, 500,000 tons in stock by November 1940, 22,000 tons used by FC in 13 weeks, enough for 1.5 times the number of operational sorties they actually flew.
It makes sense, it`s supported by WandD figures of 100 octane usage in the Battle compared to avarage British fuel consumption in November.
Wood and Dempster specifically say fuel for Fighter Command, the November report is for all British consumption.
The RAF had other commands in 1940, bombers, transports, coastal, etc, plus industry always used some for engine testing etc.
They are unable to show fuel deliveries, They are unable/unwilling to show the relative fuel usage of 87/100 octane fuel, they are unable to show serious evidence like how much fuel was issued in July, August, September or October.
Well, Isegrim, Neil has shown fuel stocks, and fuel consumption, for 1940. Mike has shown usage in 18 Spitfire squadrons during the BoB.
You have reposted a precis from an Australian, that hasn't been backed up by any original documents.
Moreover we see that they cannot give reasonable answers to why some docoments disagrees with their claims,
What documents? Don't you mean Pips interpretation of some documents? He hasn't actually quoted anything, just given his interpretation. And so far he still hasn't backed it up.
Current SpitV at +16 boost flies 290 without wep and 309 with wep. on the deck. Full out.[/quotes]
Sounds a bit slow. AA 878, a Spit VC with 4 20mm cannon, did 317 mph at sea level at 16 lbs, and AA878 was slower than several other tested Spit Vs.
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Lol only Kurfurst would compare 1944 8th AF fuel consumption with the later and more thirsty planes to a 1940 RAF comsumption with Spits/Hurris
Insane spring to mind?
As I've said your figures etc tend to be reasonably accurate, however your intepretation and comparisons leave a lot to be desired.
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Originally posted by Kev367th
Lol only Kurfurst would compare 1944 8th AF fuel consumption with the later and more thirsty planes to a 1940 RAF comsumption with Spits/Hurris
Insane spring to mind?
Desperation Kev.:rofl
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Opps wrong thread.
but thanks :), yup desperation.
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Kurfurst, do you even play this game?
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No, he just goes around the various online flightsim games BB's trying to convince them to add LW birds that existed in such small numbers they were insignificant, and at the same time trashing anything Spit related.
As I have said, his data is usually quite sound, unfortuneately it's the way he uses the data that is the problem.
i.e. comparing 1944 8th fuel usage to show the RAF couldn't of had enough 100 octane fuel for 1940 Spit/Hurris.
Despite the fact there was more than enough 100 octane fuel to support the 4000 on average sorties per week flown by the RAF during the BoB.
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Originally posted by Lord Haw Haw
No, I said Wood and Dempster said 22,000 used, I didn't say they gave the figure for how many sorties. English isn't your first languauge so I'll forgive you for this.
[/B]
So you say something, then in the next post you deny you said it...
Originally posted by Lord Haw Haw
How much fuel did a Mustang or Thunderbolt carry compared to a Spitfire I or Hurricane I? And that ignores the numbers.
FC had about 600 - 700 fighters operational, the 8th would fly far more sorties than that in a day, sometimes that many on a single raid.Originally posted by Lord Haw Haw
You made a mistake and just proven my point.
You say the FC had 6-700 fighters operational.
We know the FC`s Spitfires consumed 12 000 tons of fuel in one month, yet you tell us 22 000 tons was enough for 4 months...
When the Spitfire and Hurricanes carry less than a quarter as much fuel, and there are far fewer of them, why not? .
[/B]
You are telling us a FC Spitfire carries 4 times as much fuel as a FC Spitfire ? That`s silly. A Spit would carry 85 gallons, in 1940 or 1944.
Right. That probably fits with the average of 2,500 tons a month for the whole of 1940, consumption would have increased towards the end of the year because of the gradual switch over throughout the RAF.
Well all, or almost all, I think.
Originally posted by Lord Haw Haw
Slight logical flaw here. You are ASSuming 6250 tons a week in November 1940 was just for Fighter Command. Do you have any evidence to support that? The report certainly doesn't say it.
[/B]
Originally posted by Lord Haw Haw
Of course, the more likely conclusion is that Fighter Command was burning about 1 - 2,000 tons a week, and the rest of the RAF, as well as the aircraft and engine makers, were burning the rest.
[/B]
Which is pure specualtion of course, and you have no evidence
You only made up th
Originally posted by Lord Haw Haw
Do the records show that? I don't think Pips has ever provided them, has he?
[/B]
Well I don`t think Neil Stirling has ever provided anything than his own claims in his own post,
Originally posted by Lord Haw Haw
I suspect the records show 25% of the RAF burning 100 octane, not 25% of fighter command.
[/B]
Well you a welcome to prove that
Let`s start of fuel consumption of 87 and 100 octane fuel by Fighter command.
Originally posted by Lord Haw Haw
The problem with this is the Wood and Dempster figure. If 22,000 tons for fighter command was only powering a third of their sorties for the period, then you get about 220,000 FC sorties in 13 weeks during the BoB, or about 17,000 a week.
[/B]
According to whom... you?
No, to summarize an Australian claims that an Australian report says that. .
[/B]
An Australian report that is a copy of a British report.
Against this, a Brit, known for his wishful thinking when it comes to RAF clearances and use of high grade fuel, Neil Stirling says it was in widespread use, but cannot show anything.
British reports say an average of 2,500 tons used a week, 500,000 tons in stock by November 1940, 22,000 tons used by FC in 13 weeks, enough for 1.5 times the number of operational sorties they actually flew..
[/B]
Show me these 'British reports'....
Wood and Dempster specifically say fuel for Fighter Command, the November report is for all British consumption.
[/B]
The, the November report says only Fighter Command, and now you are making up things.
The RAF had other commands in 1940, bombers, transports, coastal, etc, plus industry always used some for engine testing etc..
[/B]
None of them used 100 octane fuel, of course.
Well, Isegrim, Neil has shown fuel stocks, and fuel consumption, for 1940. Mike has shown usage in 18 Spitfire squadrons during the BoB..
[/B]
Well if Neil Stirling showed fuel stock and fuel consumption, neither in connection with Fighter Command or proving anything.. they are just numbers without a context.
Mike Williams claims all and every Spitfire that ever met a 109 had 100 octane fuel on his site. He has absolutely nothing to prove it.
He of course, showed anecdotes about the use of 100 octane fuel in 18 Squadrons - out over 50 Sqns that saw action during BoB....
These anecdotes again, coming from the entire duration of the battle, and there are trangely only a few from July and August, and most of them from September and October, which again show the fuel was gradually introduced, and did not see widespread use until the end of the Battle.
And of course Williams makes a lot of other nonsense claims about DB 601N powered 109s only appearing in the end of the Battle, lies, just like his other claims. Why should I trust a known liar?
You have reposted a precis from an Australian, that hasn't been backed up by any original documents..
[/B]
OTOH you have reposted a precis from an Brit, that hasn't been backed up by any original documents.
What documents? Don't you mean Pips interpretation of some documents? He hasn't actually quoted anything, just given his interpretation. And so far he still hasn't backed it up..
[/B]
Well where are the documents about the widespread use of 100 octane?
Strangely, when I ask Neil Stirling about the use of 100 octane fuel in Bob, he suddenly disappears... what does that tell you.
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Uhmmmm, this:
"Now this guys claims Wood and Dampster says 22 000 tons would be enough for 6000 sorties a week - bullocks as WandD notes 22000 tons being used up"
22.000 tons /cubic?) are actually enough for some 65.000 full Spitfire tanks (85 gals)
Anyway, some 85 gals were the norm, except in cases like the Mk VIII, and in 1940 & 1941 that was enough for some 2 hrs in the air.
We have had plenty of documents stating that 100 oct was practically the norm in the BoB, so perhaps our climb performance should be adjusted to that.
Rather bad maybe, for the only thing the 109E can than do better is bunting :D
But the airscrew is of course as vital, - that however AFAIK seems to have been mostly up to 3-blade CS by 1940 summer.
Now to the original topic.
I will dig up and post a climb comparison betwen some spit I's and 109E-3 calculated in Newtons, - the Spitfire running on 87.
This was calculated to estimate the effectiveness of the wing, and it clears some issues there, for the power outputs are almost the same. Total created lift however differs quite a bit.
So, hold yer breath :D
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Originally posted by Angus
We have had plenty of documents stating that 100 oct was practically the norm in the BoB, so perhaps our climb performance should be adjusted to that.
Well if you have plenty of evidence Angus, please post it, for we are lacking evidence in this thread.
Say, the amount of 87 vs. 100 octane fuel consumed by FC during to battle would be a good start.
Otherwise, the 100 octane was norm statements looks like wishful thinking...
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Won't bother, leave it to other, for it's scattered all over the forum, and MOI is too BZY becoming rich and famous and all that to chase down stuff for you, which I belive, Milo has posted several times :D
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Ok, here comes more.
Spit I, 1939, 87, Merlin III, Rotol CS.
Climb to 10K in 3.5 mins and to 20K in 7.7
That gives respectively 2372464286N/sec to 10 K and 2156785714N/sec to 20K
Move to the Merlin XII and with a weightier aircraft, 100 oct+rotol, you go to 3.35 to 10K, and straight 7 to 20K
I belive these are 1939 figures (will someone check?) so there already seem to be some stock of 100 grade fuel.
That gives respectively 2528677612 N/sec to 10K and 2420305714 N/sec to 20K
NOTE! These are rather good Spitties, the 2 bladed ones are vastly worse.
A nice little 109 I found gave 3.7 and 8 minutes to 10 and 20K running on 87 octs,
Over to Newtons/sec, we have 2179307432 and 2015859375.
So, with almost exactly the same HP, a Spit I once it has the rotol CREATES some 5-8% more lift than it's contemporary with what most clame to be about the same power. Interesting.
(BTW, a 109E-3, 1940, weight 5875 lbs, rated at 1050 hp)
AFAIK the 100 grade was not used by the BEF in France, but entered early in the BoB.
Anyway, the 3-bladed propeller changed more in the climb rate than the conversion to 100 octs.
So, with both, you are looking into the second number which gives created lift with more than 15% between the contemporaries.
But the Spitfire is heavier, - actual time difference to alt is some 4% and 12%.
So, that was Spitties climb rate to 10K and 20K with 87 oct and 100 oct on CS.
Always on the hunt for Emil tests though.
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Angus you always post unsourced fairy tales filled with 'I think', I heard' and 'AFAIK'. No one take those posts seriously.
On topic,
I don't care what boost the Spit Ia used as standard in BoB but I will point out that just pouring high octane fuel into a tank doesn't necessarily mean you will see any significant performance gains. Things like compression, adjustment in timing etc. are necessary to take advantage of the higher octane fuel.
Just because you can show xxx amount of fuel in stock it doesn't necessarily mean that every Spit was flying around on 'magic juice'.
Outside the claims of 'stockpiles of 100 octane fuel' does any one have anything more substantial to show that 100 octane was used by:
18 Spitfire squadrons during the BoB.
Rather then 'MW said so'...
Forget the 'fuzzy' leap o'faith math...
Furball,
Kurfurst, do you even play this game?
How many people posting in this thread do you think 'play AH?' No that it matters since this forum is a open discussion forum about Aircraft and Vehicles.
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Originally posted by Wotan
How many people posting in this thread do you think 'play AH?' No that it matters since this forum is a open discussion forum about Aircraft and Vehicles.
I'm just asking... by the way he speaks it sounds like he plays the game. I dont recognise the name on here, so i asked him. Is that ok? or would you like me to edit it, sir?
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Wotan, all numbers posted are from the fourthfightergroup site.
Just can't find the link for it on the computer I am on.
The test numbers are absolute, so are the calculations.
And many people take that seriously, but alas there are always some that find some absoluteness rather uncomfortable.
When I say "I think" I rather feel good about it, because if I have to look it up, I find out I am usually right.
Much better than posting with a doubt and not saying it if you see what I mean.
Or posting with a religious agenda, tsk tsk.
Now, to a closed mind:
"I don't care what boost the Spit Ia used as standard in BoB but I will point out that just pouring high octane fuel into a tank doesn't necessarily mean you will see any significant performance gains. Things like compression, adjustment in timing etc. are necessary to take advantage of the higher octane fuel. "
So, why bother pouring stronger fuel into a tank?
Please scroll up and look at the numbers I posted.
And if you have "magic juice" (which might be no use anyway as you put it) why not use it?
Bear in mind that RR had a long experience with extreme boosting since the raceplane-days, and already pumped out 2000 hp+ in a production line Spit I in 1939, just for the test.
I think :D
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Originally posted by Furball
I'm just asking... by the way he speaks it sounds like he plays the game. I dont recognise the name on here, so i asked him. Is that ok? or would you like me to edit it, sir?
I don't care what you 'ask' and didn't say as much. I simply asked why does it matter? More importantly what bearing does have on the discussion at hand?
Folks don't 'just' do anything there is always a reason...
Wotan, all numbers posted are from the fourthfightergroup site.
That is MW's site and it does not prove what you claim it does... it may make a case on the availability of 100 octane fuel but so what..?
So, why bother pouring stronger fuel into a tank?
I don't think you understand the point. The simple act of pouring a 100 octane fuel into a Spits tank won't necessarily mean much in terms of added performance.
It may actually hurt performance.
Just like you couldn't just 'pour C3' into a 109K and run at 1.98 ata I doubt seriously you just pour 100 octane in a Spit Ia and off you go...
Things dont work that way. There would have needed to been some adjustment made to take advantage of high octane fuel.
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http://www.spitfireperformance.com/ap1590b.jpg
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Now, Wotan, you're just getting silly.
Firstly, see the above document from Justin.
Secondly this:
"That is MW's site and it does not prove what you claim it does"
You should be perfectly aware that MW's site usually offers a link to the scans of the original documents.
You can of course sit put and say nonono untill someone posts the scans directly, - then what are you going to say?
Of course there were some modifications being done to get the most out of the 100 oct fuel, as your car will also need to be set for 95 or 98 (although I've ran some on aviation fuel without probs, hehe) and as you can see from my data from MW's data with my calculations BTW, the usage of another merlin with 100 oct instead of 87 increased the climb rate by a handsome margin.
The CS to a 2-blade did more though.
And again, running on very strong juices was no novelty to RR.
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I saw that but it mentions modifications the boost control cut-off...
It states that above 10k Ft boost will drop to normal (below 12lbs).
http://www.spitfireperformance.com/spit1-12lbs.jpg
This shows that you gain 28/34 mph only below 10k...
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You talking speed or climb.
AFAIK the increased boost in early Spits didn't increase top speed a lot, - but clearly affected ROC.
Engine torque you see.......
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Oh, - and the docs:
(http://www.spitfireperformance.com/n3171climb.jpg)
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Originally posted by Angus
Now, Wotan, you're just getting silly.
Firstly, see the above document from Justin.
Secondly this:
"That is MW's site and it does not prove what you claim it does"
You should be perfectly aware that MW's site usually offers a link to the scans of the original documents.
You can of course sit put and say nonono untill someone posts the scans directly, - then what are you going to say?
Of course there were some modifications being done to get the most out of the 100 oct fuel, as your car will also need to be set for 95 or 98 (although I've ran some on aviation fuel without probs, hehe) and as you can see from my data from MW's data with my calculations BTW, the usage of another merlin with 100 oct instead of 87 increased the climb rate by a handsome margin.
The CS to a 2-blade did more though.
And again, running on very strong juices was no novelty to RR.
What Justin posted has nothing to do with your reply...
You said:
So, why bother pouring stronger fuel into a tank?
It has nothing to do with the what I suggested:
Things like compression, adjustment in timing etc. are necessary to take advantage of the higher octane fuel.
Even the link Justin provided deals with the boost control cut-off not and does not answer my question.
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What is your question then?
I mean, I gave a strong responce since you chose to doubt the benefit of using stronger octane fuel, as well as discarding evidence indicating othewise.
From what I can see, engine needed to modded only slightly to benefit from the 100 octs, - or did you ever change plugs?
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The question that was raised Angus, is that to operate on higher (+12 lbs) boost, at least 100 octane fuel was required. Evidence would be needed to see how much 100 octane fuel was used compared 87 octane fuel (which would mean +6.25 boost), so we can decide if +12 was typical boost rate during the battle or not...
The easiest way to see this is to look up the the consumption rate of 87 and 100 octane fuel by FC during the Battle.
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I recall it from the boards, but where the heck was it again...:confused:
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I don't care what boost the Spit Ia used as standard in BoB but I will point out that just pouring high octane fuel into a tank doesn't necessarily mean you will see any significant performance gains. Things like compression, adjustment in timing etc. are necessary to take advantage of the higher octane fuel.
Yes, the whole purpose of 100 octane for Fighter Command was to allow increased boost, up from 6.25 lbs on 87 octane to 12 lbs with 100 octane.
Outside the claims of 'stockpiles of 100 octane fuel' does any one have anything more substantial to show that 100 octane was used by:
quote:18 Spitfire squadrons during the BoB.
Rather then 'MW said so'...
Try this page on MW's site:
http://www.spitfireperformance.com/spit1vrs109e.html
About a third of the way down are extracts from combat reports by various pilots, showing the use of 12 lbs boost. Most of them have a scan of the actual document provided.
I saw that but it mentions modifications the boost control cut-off...
It states that above 10k Ft boost will drop to normal (below 12lbs).
http://www.spitfireperformance.com/spit1-12lbs.jpg
This shows that you gain 28/34 mph only below 10k...
Looking at the performance charts, 12 lbs boost gives around 30 mph increase over 6.25 lbs up to about 11,000ft, the speed then drops back until at about 19,000 ft there is no difference. So 12 lbs actually gives a performance advantage up to about 19,000ft, although the advantage is decreasing from 11,000ft up.
Even the link Justin provided deals with the boost control cut-off not and does not answer my question.
I don't understand, what questions do you have that this doesn't answer? Increasing boost at the same rpm will lead to a power increase.
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You are telling us a FC Spitfire carries 4 times as much fuel as a FC Spitfire ?
Huh?
I said 8th AF fighters (Mustang, Thunderbolt, Lightning) would carry many times as much fuel as a 1940 Spitfire.
That`s silly. A Spit would carry 85 gallons, in 1940 or 1944.
Um, no. In 1940 all the Spitfires in service carried about 85 gallons.
In 1944 Spitfire XIVs carried more fuel, most Spitfires were using drop tanks, a IX with a 90 gallon tank carried 175 gallons, even one with a 30 gallon tank carried 35% more fuel than the 1940 Spitfire.
Plus in 1944 Fighter Command had quite a few Mosquitos, and they'd carry a lot more.
According to whom... you?
No, according to mathematics.
We've had this sort of debate before over the Spitfire cooling, where you seem unable to understand basic maths.
The Spitfire carried 85 gallons. 1 gallon weighed 7.2 lbs. There are 2240 lbs in a ton. 22,000 tons = 49,280,000 lbs = 684,44 gallons = 80,522 85 gallon tank fulls. 80,522 full tanks over 13 weeks = 6,194 full tanks used per week.
An Australian report that is a copy of a British report.
Says Pips. Have you actually seen this report? No, neither have I.
Show me these 'British reports'
Both from Neil Sterling:
(http://www.onpoi.net/ah/pics/users/282_1123516618_100+grade+fuel.jpg)
The, the November report says only Fighter Command, and now you are making up things.
No it doesn't. In fact, it talks about overall stocks, and consumption.
(http://www.onpoi.net/ah/pics/users/282_1123517282_10m.jpg)
None of them used 100 octane fuel, of course.
Source? Bomber Command at least certainly switched to 100 octane.
He of course, showed anecdotes about the use of 100 octane fuel in 18 Squadrons - out over 50 Sqns that saw action during BoB..
No Isegrim, he's shown use of 100 octane fuel in 18 Spitfire[/i] squadrons, out of 19 Spitfire squadrons in the BoB (19 iirc). Remember, Mike's is a Spitfire site, not a Hurricane one.
OTOH you have reposted a precis from an Brit, that hasn't been backed up by any original documents.
See above. I thought you'd already seen these, though.
Strangely, when I ask Neil Stirling about the use of 100 octane fuel in Bob, he suddenly disappears... what does that tell you.
He's got better things to do than listen to your barrage of insults?
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Nice guys, well that should effectively kill all Kurfys objections off.
Meanwhile he is still to post ANYTHING that shows C3/1.98ata use by a single K-4, in another thread.
Lots of we can assume, presume etc, I asked for cold hard evidence...still waiting.
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Originally posted by Kev367th
Nice guys, well that should effectively kill all Kurfys objections off.
Meanwhile he is still to post ANYTHING that shows C3/1.98ata use by a single K-4, in another thread.
Lots of we can assume, presume etc, I asked for cold hard evidence...still waiting.
What it comes down to is "I want you to trust me cause I'm not biased and what I say is truth, while I don't trust you and everything you say is biased so it's a lie."
Those arguments never end :)
Dan/CorkyJr
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Yes, the whole purpose of 100 octane for Fighter Command was to allow increased boost, up from 6.25 lbs on 87 octane to 12 lbs with 100 octane
Ya think..? :rolleyes:
Higher octane fuel detonates at a higher temp / pressure. However, high octane fuel run in an engine with a low compression ratio would not burn as clean and you would end up with a dirty intake and not much of a performance boost. You may run into problems with spark plugs fouling, excessive heat etc...
Basically you won't get any real benefit from running higher octane gas then the engine is rated (set up) to use...
A Spit running 87 one day and pouring in 100 the next doesn't sound plausible. The question is there any evidence that shows that those spits / hurris running 100 octane under went any sort of maintenance other then what justin posted about the boost control cut-off modifications?
Just as you couldn't just dump C3 in the tank of G-10 or K-4 with out some modifications I doubt you do the same with the Spit and Hurri.
As I said before give the Spit Ia in AH 12lbs boost I don't care...
I would assume that making the engine adjustments to take advantage of 100 octane fuel would take some period of time.
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Well it took 1 day to convert a whole squadron from 100 to 150, and 1 day of flight tests, similar time for 87 to 100 maybe?
(http://www.spitfireperformance.com/no1_25lbs.jpg)
The first bulk shipment of 100-octane fuel had arrived in Britain in June 1939 from the Esso refinery in Aruba. This and subsequent tanker shipments from Aruba, Curacao and the USA were stockpiled while the RAF continued to operate on 87 octane petrol. Having secured sufficient quantities of 100 octane, Fighter Command began converting its engines to this standard in March 1940, allowing boost (manifold) pressures to be raised without the risk of detonation in the cylinders.
Starting to wonder just HOW many times we have to go over this AGAIN AND AGAIN AND AGIAN.
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Originally posted by Wotan
Ya think..? :rolleyes:
Higher octane fuel detonates at a higher temp / pressure. However, high octane fuel run in an engine with a low compression ratio would not burn as clean and you would end up with a dirty intake and not much of a performance boost. You may run into problems with spark plugs fouling, excessive heat etc...
Basically you won't get any real benefit from running higher octane gas then the engine is rated (set up) to use...
A Spit running 87 one day and pouring in 100 the next doesn't sound plausible. The question is there any evidence that shows that those spits / hurris running 100 octane under went any sort of maintenance other then what justin posted about the boost control cut-off modifications?
Just as you couldn't just dump C3 in the tank of G-10 or K-4 with out some modifications I doubt you do the same with the Spit and Hurri.
As I said before give the Spit Ia in AH 12lbs boost I don't care...
I would assume that making the engine adjustments to take advantage of 100 octane fuel would take some period of time.
Not sure about 87 to 100, but when the 100 to 150 octane switch was going on, the pilots notes, and limits were set if the Spit driver landed at a field without 150 octane. The amount of boost usable was then only +18. So they were planning for the potential of one type or the other being used in the same bird. They changed the color of the 150 octane fuel too so that there was less chance of a mistake.
Dan/CorkyJr
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Well the lower octane fuel would detonate so its understandable that boost would be limited if lower octane fuel was used.
You can go down, you can't go up...
You can run lower octane as long as you don't over boost...
However, to get the most out of the engine the engine is set up to run with 150 grade.
Kev it didn't take 1 day, it took 2. The second day for testing...
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Originally posted by Wotan
Well the lower octane fuel would detonate so its understandable that boost would be limited if lower octane fuel was used.
You can go down, you can't go up...
You can run lower octane as long as you don't over boost...
However, to get the most out of the engine the engine is set up to run with 150 grade.
Kev it didn't take 1 day, it took 2. The second day for testing...
Quote by me -
My post - "Well it took 1 day to convert a whole squadron from 100 to 150, and 1 day of flight tests, similar time for 87 to 100 maybe? "
My math off or does 1 day conversion and 1 day testing = 2 days?
(bold added by me for purposes of this reply)
Come on Wotan, please read the whole post and not just the one bit you feel you need to jump on (dont commit a Kurfy bud, your better than that).
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You edited your post after I made mine..
Those times are recorded....
Last edited by Kev367th on 08-09-2005 at 12:33 AM
My post:
08-09-2005 12:30 AM
Now you are just paying the clown...
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Yes I edited my post - because originally I had fugged up the pic link. All I had was a red X instead of a pic. you were probably posting as I was editing, I had to go back to the site and get the link.
The edit was nothing to do with the time taken, you have my word on that.
If I had been wrong I would have just said so, been wrong before and had no qualms about admitting it.
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BS the pic was there when I posted...
You edited it after I had replied and already had seen the image...
Whatever...
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The original post actually mentioned the time taken and I had put
"I know I'm looking for a link to the doc"
Then I went off to find it.
I found the doc linked to it and got red X only. So I then went back again and relinked the doc.
The final edit, which was the 12.33 one was the addition of the explantion of where and when the fuel came from. That wasn't there when you replied.
So in fact there were 4 edits the last one being the fuel shipment and source information.
None of them changed the time taken.
Be a bit dumb to link to a doc that shows 1 day conversion + 1 day testing and say 1 day.
I may be a lot of things, dumb and a liar isn't part of them.
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Whatever you say Wotan, I do not belive in yer theory that
A) 100 oct from 87 was useless.
B) A technical headache anyway.
Maybe mix it with water, huh?
Did you ever change spark plugs in yer life BTW?
(Big technical problem)
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Wotan is just being difficult.
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Originally posted by Angus
Whatever you say Wotan, I do not belive in yer theory that
A) 100 oct from 87 was useless.
B) A technical headache anyway.
Maybe mix it with water, huh?
Did you ever change spark plugs in yer life BTW?
(Big technical problem)
Besides being a flat out liar now you are just making things up out of thin air...
Quote where I said:
A) 100 oct from 87 was useless.
and/or
B) A technical headache anyway.
This thread isnt the only one where you have re-edited post after folks have replied...
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Kev , reminde me please what was/is your proffesion?
ty
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Was an Aircraft Technician for 9 year in the British Army, followd by 3 years in Civil Aviation, now a Computer Network Administrator (last 4 years).
I know big change/difference, was forced on me due to an auto accident.
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thank you
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Wotan:
"This thread isnt the only one where you have re-edited post after folks have replied..."
I think you are confusing me with someone else?
Anyway, the only times I edid is when I find a typo, and on one occasion, I was a tad to vulgar ;)
But you only need to page up a bit to see what I meen, or well, everyone else has :D
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Yup the edit reply was for your buddy Kev...
However, you are a liar as well as can be seen by your made up claims that I said such things as:
A) 100 oct from 87 was useless.
B) A technical headache anyway.
Since most of you Spit lovers are the same, liars and always distorting what others say, you can understand how some one could make such an error...
Kev the edit king and Angus the guy with the made up 'I heard', 'I think', and when that doesn't work he creates some straw man fallacy by putting words into other people's mouths...
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Wotan I've already explained what happend.
The time taken WAS NOT altered.
Your choice if you choose to believe it or not, I know what I added, all the text below the picture.
I wish there was a edit record you'd see how WRONG you are.
In fact if you 'quoted' me as you usually do this whole thing would be mute.
But even then it would be pointless, you and Kurfy are exactly the same, even after he's proved wrong he just keeps on going.
Big difference is I wouldn't take that and say it was a representation of 'most' of the LW community.
Thats a hell of a chip you got on your shoulder, considered consulting a carpenter?
All you did was read the 1st part of the sentence then go off half cocked and make an arse of yourself.
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You edited your post after I made my reply...
To deny that is lying... The times are noted and can be seen by every one...
You lied and said that you only edited your post because the image wouldn't show, that is a lie as well because your edit wasn't complete until after I made my reply. I saw the image and thats where I read the part where it stated:
May, 8th - Flying was limited to-day to aircraft tests on modified aircraft
I don't how many times you edited your post before but when I read your reply and made my post at 08-09-2005 12:30 AM you made no mention 1 day of testing...
After I made my reply you edited your post at 12:33 and then made a reply at 12:35...
You original post was made at 12:05...
26 min later and after my reply you decide to edit it?
As I said you are a liar to deny it and we both know that...
But even then it would be pointless, you and Kurfy are exactly the same,
Quote the comparisons? Again you lie...
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Here you go again Mr. Edit...
Post at 07:11 PM
edit at:
Last edited by Kev367th on 08-10-2005 at 07:28 PM
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Originally posted by Wotan
Here you go again Mr. Edit...
Post at 07:11 PM
edit at:
Last edited by Kev367th on 08-10-2005 at 07:28 PM
LOL MR PARANOID
If you think that your that important that I sit and wait for you you to reply to a post so I can change something - let me clue you in - YOUR NOT.
1 day would have made no difference to me whatsoever, I would have been partly wrong, no biggie.
Whatever you think I wouldn't use it as an excuse to say 'most' Spit lovers etc - Just shows how narrow minded, paranoid and bigoted you really are.
So fine you have your opinion of what happened, I know what happened.
Put it this way those fuel calcs I tried to do and posted, no-one has realised whats wrong with them. I didn't have to post and say I made an error please ignore them, I could of hoped nobody noticed what was wrong with them.
I don't have a problem with being wrong.
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Quit your whining Wotan.
Since most of you Spit lovers are the same, liars and always distorting what others say, you can understand how some one could make such an error...
This has to be the best laugh in the last 1000 years. Nothing can beat your 'good buddy' when it comes to lies, distorting and manipulation.
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Uhm, Wotan, did you have a "mind melding" with Izzy?
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So, back to this:
A) 100 oct from 87 was useless.
B) A technical headache anyway.
A&B: From Wotan:
1st:
I will point out that just pouring high octane fuel into a tank doesn't necessarily mean you will see any significant performance gains. Things like compression, adjustment in timing etc. are necessary to take advantage of the higher octane fuel.
and 2nd:
I don't think you understand the point. The simple act of pouring a 100 octane fuel into a Spits tank won't necessarily mean much in terms of added performance.
It may actually hurt performance.
Just like you couldn't just 'pour C3' into a 109K and run at 1.98 ata I doubt seriously you just pour 100 octane in a Spit Ia and off you go...
Things dont work that way. There would have needed to been some adjustment made to take advantage of high octane fuel.
So, if I understand you right, being able to use 100 oct fuel if it was at all available was useless, for it was a technical issue to deal with before it could be properly utilized, right?
I did point out that RR had been squeezing up to 2000 hp out of an early PRODUCTION model Spitfire, so they knew the game.
Bring 100 octs, change sparks etc, perhaps fiddle with the timing (well, it's all magnetos anyway) and it is not a big problem.
So, a question or two, did you ever fly yourself? Did you ever change sparks? and did you try to run your car on stronger or weaker fuel than it is optimized to?
Running a high octane optimized car, say 98 lead is a pain with 98 unleaded, (best to use lead liquid like STP with fuel), terrible on 95, however fine on aviation fuel (100-120)
Not kidding, tried it...nener nener
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Oh, and Izzy, sorry for the comparison, just looked at your most recent responce to me in this thread and it was actually quite subtle and most civilized :)