WWII Inline engines: Daimler Benz vs Rolls Royce vs Allison vs Klimov vs Jumo

[DaddyAck]

Originally posted by humble
I'm always amazed at how often facts get twisted here. The simple reality is that the P-38 bore the brunt of the fighting in the ETO at a critical time. It's effectiveness at higher altitudes was hampered by the same stupidity that nuetered the P-39. In the ETO (like the P-39 in the PTO initially) both plane and pilot were overmatched by the task at hand. The end result is that pilots with insufficient training flew planes with significant teething issues and absorbed tremendous losses...more as a result of poor training and lack of experience then anything else. The bottom lne was/is simple...the P-38 was the 1st plane to serve as a "deep escort", it was the 1st plane over berlin and it made everything that followed possible. Many pilots were actually flying "G"'s...it gave better then it got and inflicted many casulties. Was the P-38 "better" then the mustang....probabvly not...but the L was very capable and could have handled the task. Remember that the best plane of ther war was available and not even put into service...The F7F not only could have taken the bombers to berlin and back....it could have helped flatten it:)....

Anyone who downplays the role the 38 played in the ETO either cant read or cant comprehend....in 1943...when the job needed doing the 38 was the only "tool" for the job....in mid 1944 many options (including the 38L existed). As for the Allison vs Merlin element...the merlin was simply a vision of what the allison was designed to be...but then again the US had a 400+mph fighter in 1939 and snipped its nuts....

Amen brother, in reguards to the improtance of the 38 in the ETO.  

Oh and y'all whoom love the DB605 click here and behold the manly soud.
http://www.youtube.com/watch?v=EUcENor7X_0

[MiloMorai]

Dehavilland Hornet anyone? The F7F was this a/c's ugly sister.

[Viking]

Walter Eichhorn working the vertical:


http://www.youtube.com/watch?v=qXtb_qlk55s


Look at that 109 climb!

[Squire]

Agree Humble, too many only look at the "1945 superbirds" and pretend WW2 was fought exclusively with them, and just dis everything else. "Its not a Mustang, yada yada yada..."

P-47N, Arado, 109K, Tempest, N1K2, ect ect...its a function of the MA, where you can always pick the best rides.

[_733]

Hello,

Interesting thread. Here's an interesting comparison chart I came across in a book:

                               DB605       Merlin XX

bore                          154           137          mm
stroke                       160           152          mm
displacement            35,7          27,0         l
compr. ratio              7,2:1         6,0:1
width                        720           757          mm
height                      1010         1046         mm
length                      1740         1793         mm
frontal area              0,51          0,54          m^2
weight                      745           658          kg
weight/hp                 0,49          0,44         kg/hp
fuel usage                200           235           g/hp/h
oil usage                  5               10             g/hp/h
fuel                           87            100/130    oct
hp/litre                     42,0          54,8          hp/l
hp/area of piston     0,67          0,8            hp/cm2

                               
 What points out from those stats is that the Merlin had better hp/litre ratio, altho it achieved this by using more fuel and oil.  Merlin was also almost 100kg lighter but the size wise it was similar to DB605.
 Also it should be pointed out that the materials and fuels that DB605 used were inferior to Merlin. For example where as 109G-2's DB605 cylinder tubes were made of cromium molybdene steel. In the G-6's DB605 they were only carbon steel. So the material shortages were hampering the development of german engines (and that severely affected their TBO intervals for the worse), as was the quality of the fuel.


[edit: my nice comparison chart were fux0red by the forum... anyone knows how to fix it?]


-teemu

[MiloMorai]

Originally posted by _733
So the material shortages were hampering the development of german engines (and that severely affected their TBO intervals for the worse), as was the quality of the fuel.-teemu

What do you mean by the 'quality of fuel'? C3 fuel was equivilent to Allied 100/130 fuel late war C3 had a rich mixture of 140.

[Viking]

Oh I wish we could get C3 fuel for our 109s, even if they perked it! 2000 hp 109K would own everything!

[_733]

Originally posted by MiloMorai
What do you mean by the 'quality of fuel'? C3 fuel was equivilent to Allied 100/130 fuel late war C3 had a rich mixture of 140.

octane rating for C3 fuel was 96/100

-teemu

[_733]

Originally posted by Viking
Oh I wish we could get C3 fuel for our 109s, even if they perked it! 2000 hp 109K would own everything!

apparently DB605 DC with MW-50 gave 2200hp in G-10...

[Kev367th]

Originally posted by Viking
Oh I wish we could get C3 fuel for our 109s, even if they perked it! 2000 hp 109K would own everything!

Oh I wish someone could actually come up with one document that proves that K-4's ever used C3.

And yes I have seen Kurfursts site, no definitive proof there either.
"Assume", "safely assume", and "probably" just don't just cut it.

OTOH we have docs showing that both the XIV and LF IX (XVI) used 150 octane from mid 44, can't get them either.

[Bronk]

Originally posted by Kev367th
Oh I wish someone could actually come up with one document that proves that K-4's ever used C3.

And yes I have seen Kurfursts site, no definitive proof there either.
"Assume", "safely assume", and "probably" just don't just cut it.

OTOH we have docs showing that both the XIV and LF IX (XVI) used 150 octane from mid 44, can't get them either.

*Snicker*


Kev

Bronk

[CAP1]

Originally posted by leitwolf
Allisons win the "best sound" award.

not that this has anything to do with this thread...but i was at the reading pa airshow thisweekend.........there was a YAK9 there...and the pilot was wringing her out.....BUT.........that engine in her sounded an awful lot like an allison......any ideas therre?

[CAP1]

Originally posted by 1K3
In the radial department, nothing beats the Pratt & Whitney series.  Not even the BMW radials can beat P&W.

When it comes to Inline liquid-cooled engine, which company made THE best inline engine


[ EDIT:  Jumo is added to the list ]

another question out of curiousity??

i thought i had heard somewhere that the BMW radials were actually a pratt & whitney built under lience.....which was arranged before the war?

sounds nuts, but wondering?

[MiloMorai]

Originally posted by _733
octane rating for C3 fuel was 96/100

-teemu

Yes that is the lean mixture rating, NOT the rich mixture rating.

for your reading enjoyment,
http://www.fischer-tropsch.org/primary_documents/gvt_reports/USNAVY/tech_rpt_145_45/rpt_145_45_sec2.htm#Composition%20and%20Specifications

Please note: (The C-3 grade corresponded roughly to the U. S. grade 130 gasoline, although the octane number of C-3 was specified to be only 95 and its lean mixture performance was somewhat poorer.)

Kev, pg 174 of the Prien/Rodeike 109 book has a pic of a K-4 of 11./JG3 with the C3 decal showing clearly.

CAP1
yes it is powered by an Allison.

[Captain Virgil Hilts]

If you want to bring "exotic" avgas into this, and the HP gain, then we can always talk about the 150 octane stuff that eventually became available, and the fact that using that fuel, an Allison in a P-38 could be run at 84" MAP and turned 3200RPM+. But let's leave unverified fuel and ratings out of this.