4 ms·

The story of the Merlin V12 is really the story of E.J. Houdry, a Frenchman who came to the US in 1930 and, with plenty of help at Standard oil, perfected fluid

The story of the Merlin V12 is really the story of E.J. Houdry, a Frenchman who came to the US in 1930 and, with plenty of help at Standard oil, perfected fluid catalytic cracking of hydrocarbons. FCC gave the US AVgas with octane as high as 150 by the end of the war. This allowed much higher engine manifold pressures than the Germans before detonation, who had mostly 87 octane fuel throughout the war. Engine power is roughly proportional to manifold pressure. Source: a long rabbit trail of trying to understand why the Daimler Benz DB 605, while seemingly far more advanced on paper, was never better than parity with the smaller Merlin during WW2. Houdry being in occupied France at the wars' start would make an interesting alternate history.

raverbashing 8y ago
And before anyone asks, FCC stands for Fluid catalytic cracking
- deleted 8y ago
  [deleted]
sdfx 8y ago
Can you point me to any books on this subject? Sounds like a fascinating story to dive into in more detail.
- phasetransition 8y ago
  Not specifically about this topic, but "Oil & War: How the Deadly Struggle for Fuel in WWII Meant Victory or Defeat" is the most definitive account of the overall fuel supply factors that I am aware of.
  - Steve44 8y ago
    That book probably covers the operation to get fuel across the Channel for the D Day invasions. I'm fairly sure Brenzett Aeronautical Museum had a section about it along with some pipe and equipment when I went a few years ago. There were so many astonishing developments in the background to support the front end fighting which are so easily overlooked. Thanks for the book info, I've flagged that to get at some point.
    - phasetransition 8y ago
      Many, many, many inventions: -Babbitt bearing alloys with indium -AL7075 -Quartz oscillators -Magnetrons -Vocoding, PCM, and FSK (https://en.wikipedia.org/wiki/SIGSALY https://en.wikipedia.org/wiki/SIGSALY)
- phasetransition 8y ago
  "zeolite" materials as catalysts are something you are exposed if you study materials science (my formal education). Also W.K. Lewis is a name you'll be exposed to if you dip a toe into chemical engineering. Zeolites and Lewis are central in the FCC story. A little Googling produces their patent on this: https://patents.google.com/patent/US2451804A/en?oq=2%2c451%2c804 https://patents.google.com/patent/US2451804A/en?oq=2%2c451%2...
- phasetransition 8y ago
  A little more Googling of the ACS website produces a nice PDF historic summary of the Houdry process: https://www.acs.org/content/dam/acsorg/education/whatischemistry/landmarks/houdry/the-houdry-process-catalytic-conversion-commemorative-booklet.pdf https://www.acs.org/content/dam/acsorg/education/whatischemi...
dsfyu404ed 8y ago
Don't forget alcohol injection. Without water/alcohol added to reduce intake temperatures the high manifold pressures would have never been possible.
- Tuna-Fish 8y ago
  The germans had that too. The difference in engine power between the sides was mostly about the quality of the fuel.
  - phillc73 8y ago
    The German MW 50[1] used a mixture of methanol and water. It could be fitted to the BMW801 (Focke-Wulf Fw 190) and the DB 605 (Messerschmitt Bf109) engines. There was also the GM-1[2] which was a nitrous oxide injector and mostly used for high altitude work. [1] https://en.wikipedia.org/wiki/MW_50 https://en.wikipedia.org/wiki/MW_50 [2] https://en.wikipedia.org/wiki/GM-1 https://en.wikipedia.org/wiki/GM-1
- phasetransition 8y ago
  Water methanol injection was invented by Sir Harry Ricardo, a British engineer. It is my understanding that his book "The High Speed Internal Combustion Engine" was the definitive text on the topic of internal combustion engines in the 1930s and 40s. Google finds a reprint for a reasonable price here: https://estore.ricardo.com/shop/the-high-speed-internal-combustion-engine/ https://estore.ricardo.com/shop/the-high-speed-internal-comb...
jabl 8y ago
I've understood that a large reason why the Allied fuel had higher octane was use of TEL, and that for some reason(???) the Germans never figured it out (sounds unlikely?) or they couldn't produce it due to some other reason. Is this completely wrong, did the Germans also use TEL?
- maxerickson 8y ago
  This article doesn't make citations but seems credible: http://gasolinefuels.blogspot.com/2011/06/world-war-ii-and-octane-ratings.html http://gasolinefuels.blogspot.com/2011/06/world-war-ii-and-o... It sounds like there is a volume story there, with the US supply situation being much better.
  - Declanomous 8y ago
    The US won WWII through superior logistics as much as anything else. The Japanese strike at Pearl Harbor was in recognition of the fact that they would lose any prolonged war with the US because of the manufacturing capacity that we possessed.
- phasetransition 8y ago
  My knowledge about the role of tetraethyl lead in AVgas is limited to basically Wikipedia. But overall octane driver for both sides was feedstock quality (oil or paraffins). The Wikipedia primary source that shows the Germans also had TEL production is given as this book: https://books.google.com/books?id=FDNyGpCS9WsC&pg=PA470&lpg=PA470&dq=isbn+3-406-50276-8&source=bl&ots=PZqBKBRvEw&sig=IIojmnSg34o4tTrJ_9GEz7TmtKg&hl=en&sa=X&ved=2ahUKEwilzJDY-4DdAhWts1kKHQVlA9wQ6AEwAHoECAYQAQ#v=onepage&q=isbn%203-406-50276-8&f=false https://books.google.com/books?id=FDNyGpCS9WsC&pg=PA470&lpg=...
  - phasetransition 8y ago
    Courtesy follow-up after some more digging. If you Google for "Technical Report 145-45" you'll find a PDF with the US report on German fuels that clearly indicates their use of TEL, and at what concentration. The other major take away from that is the lean/rich Octane equivalents of the C-3 fuel were like 90/130 by wars end. So pretty good rich performance, but laggard lean, which would of course impact engine consumption rates in the larger DB 605. The allies had widely available 100/130, and some 130/150 AVgas in the Pacific best as I have been able to find. It comes back to the limited quality of hydroforming then mixed with synthetics for the Germans, vs FCC for allies. US crude wasn't of great starting quality, but they were better able to refine it at scale.

raverbashing 8y ago

And before anyone asks, FCC stands for Fluid catalytic cracking

deleted 8y ago
[deleted]

sdfx 8y ago

Can you point me to any books on this subject? Sounds like a fascinating story to dive into in more detail.

phasetransition 8y ago
Not specifically about this topic, but "Oil & War: How the Deadly Struggle for Fuel in WWII Meant Victory or Defeat" is the most definitive account of the overall fuel supply factors that I am aware of.
- Steve44 8y ago
  That book probably covers the operation to get fuel across the Channel for the D Day invasions. I'm fairly sure Brenzett Aeronautical Museum had a section about it along with some pipe and equipment when I went a few years ago. There were so many astonishing developments in the background to support the front end fighting which are so easily overlooked. Thanks for the book info, I've flagged that to get at some point.
  - phasetransition 8y ago
    Many, many, many inventions: -Babbitt bearing alloys with indium -AL7075 -Quartz oscillators -Magnetrons -Vocoding, PCM, and FSK (https://en.wikipedia.org/wiki/SIGSALY https://en.wikipedia.org/wiki/SIGSALY)
phasetransition 8y ago
"zeolite" materials as catalysts are something you are exposed if you study materials science (my formal education). Also W.K. Lewis is a name you'll be exposed to if you dip a toe into chemical engineering. Zeolites and Lewis are central in the FCC story. A little Googling produces their patent on this: https://patents.google.com/patent/US2451804A/en?oq=2%2c451%2c804 https://patents.google.com/patent/US2451804A/en?oq=2%2c451%2...
phasetransition 8y ago
A little more Googling of the ACS website produces a nice PDF historic summary of the Houdry process: https://www.acs.org/content/dam/acsorg/education/whatischemistry/landmarks/houdry/the-houdry-process-catalytic-conversion-commemorative-booklet.pdf https://www.acs.org/content/dam/acsorg/education/whatischemi...

dsfyu404ed 8y ago

Don't forget alcohol injection. Without water/alcohol added to reduce intake temperatures the high manifold pressures would have never been possible.

Tuna-Fish 8y ago
The germans had that too. The difference in engine power between the sides was mostly about the quality of the fuel.
- phillc73 8y ago
  The German MW 50[1] used a mixture of methanol and water. It could be fitted to the BMW801 (Focke-Wulf Fw 190) and the DB 605 (Messerschmitt Bf109) engines. There was also the GM-1[2] which was a nitrous oxide injector and mostly used for high altitude work. [1] https://en.wikipedia.org/wiki/MW_50 https://en.wikipedia.org/wiki/MW_50 [2] https://en.wikipedia.org/wiki/GM-1 https://en.wikipedia.org/wiki/GM-1
phasetransition 8y ago
Water methanol injection was invented by Sir Harry Ricardo, a British engineer. It is my understanding that his book "The High Speed Internal Combustion Engine" was the definitive text on the topic of internal combustion engines in the 1930s and 40s. Google finds a reprint for a reasonable price here: https://estore.ricardo.com/shop/the-high-speed-internal-combustion-engine/ https://estore.ricardo.com/shop/the-high-speed-internal-comb...

jabl 8y ago

I've understood that a large reason why the Allied fuel had higher octane was use of TEL, and that for some reason(???) the Germans never figured it out (sounds unlikely?) or they couldn't produce it due to some other reason. Is this completely wrong, did the Germans also use TEL?

maxerickson 8y ago
This article doesn't make citations but seems credible: http://gasolinefuels.blogspot.com/2011/06/world-war-ii-and-octane-ratings.html http://gasolinefuels.blogspot.com/2011/06/world-war-ii-and-o... It sounds like there is a volume story there, with the US supply situation being much better.
- Declanomous 8y ago
  The US won WWII through superior logistics as much as anything else. The Japanese strike at Pearl Harbor was in recognition of the fact that they would lose any prolonged war with the US because of the manufacturing capacity that we possessed.
phasetransition 8y ago
My knowledge about the role of tetraethyl lead in AVgas is limited to basically Wikipedia. But overall octane driver for both sides was feedstock quality (oil or paraffins). The Wikipedia primary source that shows the Germans also had TEL production is given as this book: https://books.google.com/books?id=FDNyGpCS9WsC&pg=PA470&lpg=PA470&dq=isbn+3-406-50276-8&source=bl&ots=PZqBKBRvEw&sig=IIojmnSg34o4tTrJ_9GEz7TmtKg&hl=en&sa=X&ved=2ahUKEwilzJDY-4DdAhWts1kKHQVlA9wQ6AEwAHoECAYQAQ#v=onepage&q=isbn%203-406-50276-8&f=false https://books.google.com/books?id=FDNyGpCS9WsC&pg=PA470&lpg=...
- phasetransition 8y ago
  Courtesy follow-up after some more digging. If you Google for "Technical Report 145-45" you'll find a PDF with the US report on German fuels that clearly indicates their use of TEL, and at what concentration. The other major take away from that is the lean/rich Octane equivalents of the C-3 fuel were like 90/130 by wars end. So pretty good rich performance, but laggard lean, which would of course impact engine consumption rates in the larger DB 605. The allies had widely available 100/130, and some 130/150 AVgas in the Pacific best as I have been able to find. It comes back to the limited quality of hydroforming then mixed with synthetics for the Germans, vs FCC for allies. US crude wasn't of great starting quality, but they were better able to refine it at scale.