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

[Crumpp]

Originally Posted by Crumpp

I don't have a link Glider. These are not posted on some website but part of my collection. I scan the pages and post them.



Exactly. Quite a large "Fly in the Ointment" for silly claims like:

And depending on the dates you pick for the battle to be over:

You wonder why I question what you claim "is known." Facts are it is not known.

See above, Glider.

[Glider]

Originally Posted by Crumpp

See above, Glider.

All I see is someone who will not scan and post the sections that I am now asking for, a third time, as I am confident that those sections on the Propeller and the pilot protection would give us a good idea as to which version of the Spitfire your pilots notes refer to.

Can you even tell us where you got them so I can obtain a copy?

I should remind you that you accused me of posting selective and misleading papers. My reply was to ask which paper you are talking about and I would give you everything I have on those papers or get a full copy for you when I am next at the NA which will be next week. You have not yet told me which paper of mine you were referring to and the offer is still open until next week. I have made this offer twice.

Some people who would think that this insistance on two sets of rules, one for when you post papers, and one where others post papers as a little dodgy?

Kurfurst, if you are reading this the offer is open to both of you. I am going for other purposes so will not spend a lot of time on this topic, but if you can agree one paper I will supply it.

[Al Schlageter]

Crumpp still is evading identifying the 16 squadron that he claims were the only squadrons that used 100 octane fuel.

[winny]

If we are now taking the 1938-9 Spitfire pilot's notes literally (like Crumpp is) then we also need to replace the reflector sight with an iron sight, remove the bullet proof glass and at least 30 other modifications that were in the original notes that were simply out of date in 1940.

The pilot's notes were written using the 2nd production Mk1 (it went specifically to the RAF for this exact purpose)

Like it says in the front of the notes.

"Air Ministry Orders and Vol. II leaflets as issued may affect the subject matter from time to time. It should be understood that amendment lists are not always issued to bring the publication into line with orders or leaflets and it is for holders of this book to arrange the necessary link up.

When an order or leaflet contradicts any portion of this publication an amendment list will generally be issued, but when this is not done, the order or leaflet must be taken as the over-riding authority"


I'd like to see a scan of the amendment certificate in the front of this "June 1940" pilot's note book.

[Crumpp]

So even with 100 octane fuel being the common fuel in January 1942, the "All out" limit remained +6 1/4. So obviously there is no relation between introduction of 100 octane fuel and the fact that the "All out" limit remained +6 1/4.

Yes!!

Read the instructions for using +12lbs boost. First you have to override the normal controls and it emphasized that it is a very overloaded condition.

+12lbs is almost 3 times more pressure than the engine was designed to handle.

The modifications to the cylinder heads changes the frequency harmonics in order to reduce the incidence of cylinder head cracking. It does not increase the design strength of the engine.

BMW did the same thing when attempting to raise the motor to 1.8ata in the BMW801D2. The service trials resulted in a high incidence of cylinder cracks so they changed the cylinder barrel liners to ones that conformed harmonically under the new load.

Think of a tuning fork, if you want to change the frequency you adjust the length of the tines. To change the frequency in the merlin III, they added .020 inches to the spigot.

[Robo.]

Originally Posted by Crumpp

Yes!!

Read the instructions for using +12lbs boost. First you have to override the normal controls and it emphasized that it is a very overloaded condition.

Yes of course, but it was possible therefore it should be possible in the sim, too. No matter how you look at it, I really try hard to see your point, but you're wrong on so many levels I am afraid. Why are you doing this anyway?

Originally Posted by Crumpp

+12lbs is almost 3 times more pressure than the engine was designed to handle.

It is approximately 2 times more than original nominal rating. And the RR engineers have had slightly different approach to getting more power from their designs - testing, breaking and consequently reinforcing what breaks first, hence so many mods and pilot notes amendmets that seem to confuse you.

+16lbs was 3 times more pressure and it was still used on Sea Hurricanes on the very same engine for obvious reason - no problem except drastically limited lifespan of the engine.

Honestly, Crumpp

[41Sqn_Banks]

Crumpp is right that +12 boost is about 3 times higher than the maximum continuous rating (+ 4 1/2), which is the highest rating that is not considered a overload condition (see attachment). I don't know if this was the rating the engine was designed for.

IIRC we know that +12 boost reduced the life-time to about 20 hours instead of 100 hours at maximum continuous rating.

[Al Schlageter]

The 12lb boost was a reduction from the 17lb boost that there normally would be. Yes there are references to this boost of 17lb. The boost was cut back to 12lb for reliability.

Crumpp still is evading identifying the 16 squadron that he claims were the only squadrons that used 100 octane fuel.

[Robo.]

Originally Posted by 41Sqn_Banks

Crumpp is right that +12 boost is about 3 times higher than the maximum continuous rating (+ 4 1/2), which is the highest rating that is not considered a overload condition (see attachment). I don't know if this was the rating the engine was designed for.

I see what he means now, thank you. It doesn't make much sense though - engines are designed for certain HP and that was never achieved at max. continuous rating as far I can tell.

[41Sqn_Banks]

Originally Posted by Robo.

I see what he means now, thank you. It doesn't make much sense though - engines are designed for certain HP and that was never achieved at max. continuous rating as far I can tell.

Rolls Royce gives 990 b.h.p as "international power rating" (+ 6 1/4 Boost with 2,600 RPM at 12,250 feet), see http://forum.1cpublishing.eu/attachm...8&d=1334724563.

Don't we have to convert the boost values to ata before we compare them make a statement about the factor between them? Otherwise the atmospheric pressure offset is not eliminated.