Inaccurate performance data for BOB fighters in COD comparing to RL data

[winny]

Ignoring the tit for tat for a moment.

Can anyone tell me if a Merlin that had been converted to 100 could run on 87?

I don't want guesses or in my experience answers.. Please.

The reason I ask is that it appears that in the German machines it was not possible to interchange the fuel. (87 oct B-4 & 100 oct C-3) (Fighter Arm pamphlet Nr.1410144)

Also I recall reading somewhere that a converted Merlin would not run on 87 because of the modifications. I cannot find where I read it though.. Maybe I dreamt it!

[41Sqn_Banks]

Originally Posted by winny

Ignoring the tit for tat for a moment.

Can anyone tell me if a Merlin that had been converted to 100 could run on 87?

I don't want guesses or in my experience answers.. Please.

The reason I ask is that it appears that in the German machines it was not possible to interchange the fuel. (87 oct B-4 & 100 oct C-3) (Fighter Arm pamphlet Nr.1410144)

Also I recall reading somewhere that a converted Merlin would not run on 87 because of the modifications. I cannot find where I read it though.. Maybe I dreamt it!

Merlin II/III: Yes

http://forum.1cpublishing.eu/attachm...0&d=1334948575

"100 octane may be used, if the engine has been suitable modified", if it wouldn't be possible it would state "must be used".

Merlin XII: Yes

http://forum.1cpublishing.eu/attachm...8&d=1332086871

It shows different engine limitations depending on used fuel.

For all British engines: Yes

http://forum.1cpublishing.eu/attachm...0&d=1334727256
http://forum.1cpublishing.eu/attachm...1&d=1334727263

Clearly states that it is possible, however the operational limits are lower.

[Glider]

Kurfurst
That file is many hundreds of pages long and you are not going to get it all, which meeting are you interested in or which paper of mine do you consider to be partial and I will post the rest.
I have looked up previous postings of yours and the one paper you have mentioned is the Oil Co ordination committee meeting after the May meeting when the roll out was confirmed as being complete. If you want something apart from that you need to be more precise

[Crumpp]

Here's the page from the "June, 1940" Pilot's Notes that specifies the fuel (which actually is from "May, 1940" as can be seen in the "List of Content" of Section 1).

"100 octane may be used, if the engine has been suitable modified", if it wouldn't be possible it would state "must be used".

Of course and this is same note appears in the 1939 Operating Notes.

The fly in the ointment is the January 1942 Operating Notes clearly state, OPERATIONAL UNITS-100 OCTANE ONLY.

January 1942, Pilots Operating Notes, Spitfire Mk I:



That is definative and it is a fact all operational units flying a Spitfire are using 100 Octane in January 1942.

Before the January notes, the only mention of 100 Octane is "100 octane may be used, if the engine has been suitable modified" That "may be used....IF" is definative as well. All operational units flying a Spitfire Mk I were not using 100 Octane in June of 1940...for a fact.

[Crumpp]

That is Kurfurst's MO

He has allways played both sides of the argument, posting in bold the items that support his arguments, ignoring the items that weaken his arguments.

With that said

Let's play thier game for the moment..

Lets assume that all RAF planes were running 87 oct and all nazi planes were using 100 oct..

Thus they are asking us to belive that the Spitfires runnin 87 oct were able to clear the skys of 109 running 100 oct

Would be interesting to see how they try and spin that one

Ace of Aces...ie Tagert, It was you who did not understand atmospheric conditions effect on aircraft performance and was crying about gameshapes being mismodeled.

When I pointed that out, you spent pages attacking me personally.

Then you proceed with "testing" showing the creation and destruction of energy. I tried to help you by explaining how a specific set of formulation, Total Energy Concepts for Aircraft Performance works and once again you spent your time flinging personal insults.

I would ask the mods to please remove those who contribute nothing but personal insults.

There is good information in this thread and I think we are getting closer to the answer.

[NZtyphoon]

Originally Posted by Crumpp

Of course and this is same note appears in the 1939 Operating Notes.

The fly in the ointment is the January 1942 Operating Notes clearly state, OPERATIONAL UNITS-100 OCTANE ONLY.

January 1942, Pilots Operating Notes, Spitfire Mk I:



That is definative and it is a fact all operational units flying a Spitfire are using 100 Octane in January 1942.

Before the January notes, the only mention of 100 Octane is "100 octane may be used, if the engine has been suitable modified" That "may be used....IF" is definative as well. All operational units flying a Spitfire Mk I were not using 100 Octane in June of 1940...for a fact.

Then back up your "facts" with something substantive:

Explain how 16 Squadrons consumed 52,000 tons of 100 Octane fuel in just 3 months (Jul - October) with documentation.

Explain which squadrons were selected for your "intensive operational trials" and explain how the RAF ensured that only the selected units were supplied, with documentation.

You insist that the RAF needed to have 800,000 tons of 100 octane in reserve, based on pre-war papers, yet you have never explained why the RAF was using "Other Grades" when the reserves of those were falling below the reserves of 100 Octane as the battle progressed; if, as you state

Originally Posted by Crumpp

Winny,
That does not necessarily mean aircraft were feeling a shortage. It does mean the strategic reserves are short. Remember, they originally wanted 800,000 tons in reserve before a single operational aircraft used the fuel.

Yes, there was a shortage because the Strategic reserve to production ratio is just not where it should be.

I repeat, the "reserves to production ratio" of "Other Grades" of fuel was falling below that of 100 Octane; taking that hypothesis to its logical conclusion the RAF would not have been using any fuel.

But, wait, there's more, "That does not necessarily mean aircraft were feeling a shortage"...really hedging your bets there Crumpp.

You then go on to state:

Originally Posted by Crumpp

Great example of why looking at strategic logistics is a horrible method to predict operational conditions is the German late war fuel situation on the western front. Strategically, Germany had plenty of fuel in their reserves. The shortage was at the operational side due to main supply route bottlenecks caused by allied airplanes shooting up the stockyards, railheads, and trucks!

A poor comparison because the RAF's supply system was not put under the same strain and the RAF was able to supply its airfields throughout the battle.

All this means is that you want things both ways - first you insist the reserves were inadequate, and have spent ages pushing that position - now you insist weeell it doesn't matter anyway.

One or t'other - did the RAF have enough reserves of 100 Octane fuel to potentially supply all frontline fighter squadrons throughout the battle - yes or no?

[Seadog]

Originally Posted by winny

Ignoring the tit for tat for a moment.

Can anyone tell me if a Merlin that had been converted to 100 could run on 87?

I don't want guesses or in my experience answers.. Please.

The reason I ask is that it appears that in the German machines it was not possible to interchange the fuel. (87 oct B-4 & 100 oct C-3) (Fighter Arm pamphlet Nr.1410144)

Also I recall reading somewhere that a converted Merlin would not run on 87 because of the modifications. I cannot find where I read it though.. Maybe I dreamt it!

The 100 octane mods specify different plugs. Typically you will not want to run 87 octane in an engine with 100 octane plugs.

[41Sqn_Banks]

Originally Posted by Seadog

The 100 octane mods specify different plugs. Typically you will not want to run 87 octane in an engine with 100 octane plugs.

According to AP1590B A.L. 4 (November 1940) the different sparking plugs are "very desirable" but not required. So using 100 octane with the regular sparking plugs seems to work, however it doesn't sound like a good idea. In addition it doesn't mean that the 100 octane plugs work satisfactory with 87 octane.

[Crumpp]

According to AP1590B A.L. 4 (November 1940) the different sparking plugs are "very desirable" but not required. So using 100 octane with the regular sparking plugs seems to work, however it doesn't sound like a good idea. In addition it doesn't mean that the 100 octane plugs work satisfactory with 87 octane.

The major change is the cylinder heads. Without those, you are going to have cracking.

In addition it doesn't mean that the 100 octane plugs work satisfactory with 87 octane.

Exactly. It specifies the four types of plugs which may be used for 100 Octane. You would have to look the spark plugs authorized for 87 Octane and see if any of them match the part numbers.

I actually have to put the certificate that comes with a set of plugs in the logbook of the aircraft we work on and sign it. It is a required entry and the certificate must state the plugs are authorized to use in the aircraft.

Aircraft maintenace is very tightly controlled by convention.

[41Sqn_Banks]

Originally Posted by Crumpp

The major change is the cylinder heads. Without those, you are going to have cracking.



Exactly. It specifies the four types of plugs which may be used for 100 Octane. You would have to look the spark plugs authorized for 87 Octane and see if any of them match the part numbers.

I actually have to put the certificate that comes with a set of plugs in the logbook of the aircraft we work on and sign it. It is a required entry and the certificate must state the plugs are authorized to use in the aircraft.

Aircraft maintenace is very tightly controlled by convention.

Now wait ... did I understand that correct:

Didn't you just say some posts above that the use of 100 octane fuel on one day doesn't mean it was used on the next day?
So the RAF filled there aircraft on one day with 100 octane, changed the sparking plugs, did all the certificate stuff. On the next day the drained the tanks, filled in 87 octane, reverted to the old sparking plugs, again certificate stuff.

And if they were really fast they might find have one hour per day to fight the Luftwaffe.

Seriously?