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

[NZtyphoon]

The Merlin tested in the Hurricane ran for 8 1/2 hours on 100 Octane fuel at 12 pounds boost, but the test was terminated after 49.5 hours by a glycol leak into one cylinder. The document goes on to note that this problem was rectified by modifying the cylinder head joints, a modification which was retrofitted to earlier Merlins and would have been incorporated into later Merlins. ( paras 4 & 6)

"It will be noted from the Service reports that an approximate increase in speed, due to the use of emergency 12 lbs. boost, of 28/34 m.p.h. is obtained depending on the altitude flown up to 10,000 feet." (para 8.)

This most likely applys to both the Hurricane and Spitfire. Gleed, below, 19 May 1940, notes an increase of 30 mph for his Hurricane.

"The modifications to the boost control cut out to limit the maximum boost to 12 lbs. sq. in are simple and in hand (otherwise full throttle would give about 17 lbs. sq. in.)" para 9.

[Osprey]

I thought Kurfurst had "only a passing interest" in the RAF?

[Al Schlageter]

Originally Posted by TomcatViP

Regarding the HP of the Merlin as of NZT sources it : He is confusing SHP and BHP. It was a standard use in RR to give the power of an engine without the charger fitted as the methods used to calculate the true corresponding power at alt from a bench test ran on the ground were not reliable (source RR - already mentioned by myself somewhere in the thread).

How ever was the engine ever run to obtain the hp number as the supercharger was between the carb and the cylinders?

As Barbi and Eugene are so positive that 87 octane fuel was still in widespread use by RAF FC, they should have no trouble listing the squadrons, and the bases they flew from, that were still using 87 octane fuel late in the BoB.

As for Barbi's comment of fuel consumption, he is no doubt referring to the useless garbage graph (no source for the data points ever given) he posted earlier in this thread. Useless garbage because the consumption of 87 octane fuel includes that other RAF Commands (Coastal, Bomber, Training et al).

There's of course this paper of 7 August that supposed to 'authorize' all Commands for using 100 octane

Now this statement shows what a double standard Barbi has as he uses a German document, and [v]ONLY[/b] this document, giving authorization for 1.98ata use to 4 Gruppen with the Bf109K-4 and even goes on and speculates that other K-4 and G-10 units also used 1.98ata boost. This contradicts Eugene's emphatic statement that German units never ever did modifications without official authorization.

It is not known if and how many units had converted to 1,98 ata manifold before that order came, but it should be noted these units, in particular III./JG 27, III./JG 53 and IV./JG 53 were the major users of the Bf 109 K-4 in the Lufwaffe. The other units effected are not known at present, but given the abundance of photograph depicting G-10 and K-4 fighters belonging to other units, marked for C-3 fuel use - a likely sign of the DC engine at 1,98 ata - the boost increase was likely not limited to JG 27 and JG 53 alone.

[Al Schlageter]

Originally Posted by Osprey

I thought Kurfurst had "only a passing interest" in the RAF?

He does until the mediocre aircraft of the RAF put the boot to his uber Luftwaffe. I don't understand his objection to 100 octane fueled Spitfires and Hurricanes during the BoB as this give him a good excuse for the failure/defeat of the Luftwaffe in achieving air superiority over southern England. As it now stands, it was inferior fighters which did the job.

[Ernst]

Originally Posted by Al Schlageter

He does until the mediocre aircraft of the RAF put the boot to his uber Luftwaffe. I don't understand his objection to 100 octane fueled Spitfires and Hurricanes during the BoB as this give him a good excuse for the failure/defeat of the Luftwaffe in achieving air superiority over southern England. As it now stands, it was inferior fighters which did the job.

However its an error admit that the Luftwaffe failure was due to the superiority of the Spitifire. I already commented but i ll do it again. How many 109s in percentage of the ones lost were lost simply by lack of fuel instead being shot down?

I am most sure than this number is far from insignificant. I ll be not surprise if a large number of German fighter simply did not come home because fuel and not because they were shot down.

The spitfire were not so succesfull against the 109s in other theaters. At mediterranean and Afrika the allied resources are bigger. And the RAF suffered heavy loses in Afrika and Malta. The failure of the Luftwaffe in this scenarios was mainly because they were outnumbered and low of fuel. And they performed very well. And the spitfire was there.

[Al Schlageter]

Originally Posted by Ernst

The failure of the Luftwaffe in this scenarios was mainly because they were outnumbered and low of fuel. And they performed very well. And the spitfire was there.

Eugene will argue til the cows come home and the moon turns blue that the Luftwaffe was not outnumbered.

How many 109s in percentage of the ones lost were lost simply by lack of fuel instead being shot down?

Luftwaffe Losses in the Battle of Britain
(July-October 1940)

Data from “The Narrow Margin”, cleaned up by Robert Herrick
http://www.alternatewars.com/WW2/See..._LW_Losses.htm

[Ernst]

What is considered inside "operational" and "non-operational" loses?

[Al Schlageter]

Originally Posted by Ernst

What is considered inside "operational" and "non-operational" loses?

Non-operational would be a test flight, a training flight or a transfer flight.

[NZtyphoon]

Originally Posted by TomcatViP

It was a standard use in RR to give the power of an engine without the charger fitted as the methods used to calculate the true corresponding power at alt from a bench test ran on the ground were not reliable (source RR - already mentioned by myself somewhere in the thread).

Evidence please?

[TomcatViP]

Browse back the thread. I hve alrdy discussed this point and listed the source (RR history book).