Gripen says:
As far as I know, the original documents (Captured German and Japanese material) were transfered bit by bit back to Germany and Japan starting from as early as sixties. NASM has just microfilmed copies of these. Problem is that there appear to be no logic how the original documents were scattered to different archives; BAMA, DM... you name the archive, actually some have been found from UK.
They were returned to their original owners if they still existed. If not the documents where given to the German or Japanese Government.
Gripen says:
Actually RAE found out in the bench tests that with original plugs engine did run roughly with both fuels (British 100 octane and 1943 version of C3). With Siemens plugs the engine did run well with both fuels and output was found to be normal. AFAIK the only other change they made to engine was to adjust injection pump to roughly compensate different specific gravity of the fuels (I have posted summary here).
Which is exactly what I said. Unfortunately the Germans changed to composition of C3. Simply research the results of allies changing fuel composition:
Of course everyone knows that C3 ended up with so much lead in it that the Germans began to experience seperation issues.
Gripen says:
The C3 version used in the RAE tests had specific gravity 0,772 so it was improved version of the C3.
I am sure it did. The density of the fuel did not change until 1943 when the Germans began hydrogenation of their fuels.
Unless of course you wish us to believe that in the 4 days from when the report was typed (19 June 1942) and Fabers plane fell into British hands (23 June 1942), the Germans were able to refine and transport sufficient quantities of improved alkane ratio fuel to the frontline Geschwaders.
Rather silly if you think about it.
Gripen says:
There were no complaints about rough running during tests of the PE882, PN999 and PM679 (also earwitnesses, like Brown, confirm good running).
Maybe so however none of those aircraft are fighter varients. They were crashed or landed by mistake during the "Terrorflieger" Campaign. IIRC, they are FW190G's. Completely different aircraft and motor set up from an FW190A fighter.
I get the feeling though that since the RAE just chalked up “rough running” as a characteristic of the BMW801 that they simply did not point out what in their conclusions is the obvious.
Gripen says:
If you read the report you will find out that allies knew about the improvement quite soon and they had enough samples even for bench tests as pointed out above.
Sure they may have used some of their very small stock to try and figure out how the motor could best work with allied fuels. Makes perfect sense to me especially if you want the motor to perform to standard.
However they did not have enough C3 fuel for flight-testing. They did not even have enough to get a decent survey of the fuel composition as noted in the last section of the first page:
Gripen says:
Early US fuels had lower aromatic content than British and that might explain the difference.
It is interesting that in the Post War era when extremely high-octane fuels were developed the former Western Allies adopted many of the practices used by the Germans in fuel blending. Higher aromatics, paraffin content, Lead increase and using alkanes for antiknock protection were adopted to overcome problems.
However during the war the allies had no idea as to why the Germans formulated fuel as such.
Not surprising as the Germans were leaders in fuel technology in the 1920's and invented the hydrogenation process. Does not make much sense that they would suddenly lose their wits does it?
Fuel is actually a big issue in our restoration of "White 1". None of the restored German engines are able to run at full boost on natural petroleum Avgas. Ours will most likely not run at full boost either. At lower manifold pressure it should run fine. We are discussing having a petrochemical analysis done of late war C3 and the possibility of custom additives.
Gripen says:
BTW do you have some proof on 14 blade cooler fans on the 801D2? All documentation I have seen indicate that it was a 801TS specific feature (like FW spec sheets).
Yes. You can find it at the NASM archives. It is in multiple documents actually. How much sense does it make to keep a piece of equipment that lowers your planes performance dramatically?
Gripen says:
AFAIK no one is looking for the best performance but performance of a standard service plane.
That is actually a wide range of performance as well Gripen.
All the best,
Crumpp
