WW2 without V-1710: options for the Allies?

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Both the Allison and Merlin have fork and blade rods. The blade rods have two bolts, but the same bearing is held in palce by the fork rods, which has 4 bolts. It is essentially a 6-bolt main cap retention. The Allison rods are VERY strong and can withstand 3,850 HP and more. They make that every year at Reno where the two front-running P-51's use composite engines that started life as Merlins and are running Allison rods among other modifications. The Merlin rods won't take quite the same horsepower, but are VERY strong when compared with any stock automotive engine.

I know the NHRA Top Fuel dragsters are pushing 8,500 HP ... but it's only for about 4 - 5 seconds. Try making these engine live for even 30 minutes and you'll never get it done. And they aren't anywhere near stock engine parts. The rods in Strega and Voodoo are stock Allison G-6 rods.

If you are sticking to 2,400 HP and less, the stock Merlin rods are just fine. They might take a bit more, but you'd be pushing them hard if you do it.
 

While they may be similar TPI and of the same basic diameters, the big difference between Whitworth and Unified Threads is the angle of the thread. The Unified Thread has an included angle of 60° (as does metric) compared to 55° for Whitworth. BA threads have an angle of 47.5°. So production of tools and dies requires new sets of grinding wheels.

Also, while automatic machines can spit out machined screws quickly - we had one that made BA screws - it is not the only way to make screws and bolts. They can be rolled - but I'm not sure when that first started. These also require dies of the correct form.
 

You state that Ford started work on the R-2800 in Aug/Sept (I used the Sept date for the 3.5 month figure) and Packard on June 27 1940, so Packard/Merlin had a 2-3 month lead over Ford/R2800 yet look at the production figures:



In the first 6 months of production, Ford built 947 R2800s versus only 636 Packard Merlins despite the two month Packard Lead. Push Ford's R2800 plant back two months and they then produce another 989 engines or 1936 R2800s versus only 636 P.Merlins when both start on the roughly the same date - this shows the disaster to Allied and Commonwealth fighter production caused by Ford's reneging on the deal. Of course at the same time as this is going on Ford's engineers are able to completely redesign the Merlin as the V1650 GG Aero Engine which shows the depth of Ford's resources in both the design and production departments.
 
This is starting to be funny. You can "what if" history to death. It was what it was, and Ford made his choice and could not be made to do otherwise. This is the USA, not the Soviet Union.

I think Shortround is right, the delay was minimal, but nobody can say exactly what it cost as the resources were available when they were available, and not before. Even if it cost 2 - 3 months, we probably would not have gotten places overseas much sooner anyway. If we are talking 1 - 3 months of delay, what possible difference can it have made?

The bombing campaign started when it started, and would not have been moved up unless EVERYTHING was ready. I haven't seen any proof as yet that the Allied campaign was lagging because of lack of US Merlin production, and that is what delayed things.
 
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Sorry, my eyes glossed over reading all the posts on this topic. Somehow, I came away from this fantasizing that if the Allison V-12 didn't make the cut, there may have been Wright R2600 P-36's running around at some point. Droooool.
 
Sorry, my eyes glossed over reading all the posts on this topic. Somehow, I came away from this fantasizing that if the Allison V-12 didn't make the cut, there may have been Wright R2600 P-36's running around at some point. Droooool.


Would that have been any better than the R-1830 P-36?

Sure, there is more power but there is also a lot more weight and a larger frontal area.
 
Sorry, my eyes glossed over reading all the posts on this topic. Somehow, I came away from this fantasizing that if the Allison V-12 didn't make the cut, there may have been Wright R2600 P-36's running around at some point. Droooool.

Not to mention trying to fit a prop about 1 ft larger in diameter which means longer landing gear which means.................
 

Reason for detailing the head/chamber design was to point out plug location. A big deal when detonation is a key factor in determining performance potential. It is probable that this engine would not have been ready any sooner than the GAA Tank V8 was. Dec 41- Jan 42. So that would put the Ford out of the running for this exercise. Maybe I should have chimed in on the "What if no US built Merlins" Thread.

Any how, I'm in the final legal phase of securing loan of the Ford V12 Tank engine GAC, for tear down and study. A photo essay will be published in a magazine that I write for. However, if anyone here is interested, I can present it in much greater detail after published.
 
Hey, this is a fantasy, don't throw facts and reality in the way!!!! As a hot rodder, first you put the big engine in, then you figure out all the other stuff. How about a nice thick cord prop, stretch the diameter to as much as can be handled. Put the P-40K airframe behind it with the larger fin area.

Which if that happend, then when the British asks North American to produce the airplane, and North American counters, we have a R2600 P-51A. Yum.

Sorry, ranting.
 
I found this on the web:


So Ford's involvement did begin in 1939 and Ford engineers had had previous experience with the Merlin, both in terms of design and production; thus Ford USA was ideally situated to begin production of the Merlin under license.
 
Not really, Ford of France had a look and a few Ford of America engineers helped them look. Now you have the reverse problem, trying to turn the British drawings ( and thread sizes) into metric drawings and measurements. Now the American engineers go back to America with what? No computers so ALL drawings are done by hand and there were thousands ( if not tens of thousands) of drawings involved so the American engineers would have needed numbers of crates to get any number of any short of drawings back to the US. There is no fax, etc. The actual drawings (or hand made copies or photographs) had to be physically shipped even from Ford of England.

There is also some dispute about the two piece cylinder blocks. Some people say Packard designed them and others say Rolls-Royce did. Packard, because they were tooling up a new production facility was in a better position to start producing the 2 piece cylinder blocks since there was NO existing tooling to change over and no delay or loss of production like would have occurred in the English plants making the Merlin at the time.

And having a few engineers who looked at the Merlin in terms of French production may or may not help you when planning American production. My father was a production engineer for Colt in 1960s and 70s and not only worked on the US Colt production but helped set up factories in Korea and the Philippines to make M-16s. They often had to design different jigs and fixtures because the two oriental factories not only used different machinery than the home plant but different machinery from each other due to different monthly production goals and different goals (future production) after the initial rifle contracts were completed.
Not sure what Ford of France had for production machinery or what they planned to buy to equip production line vs what Ford of America had available. Please remember that many lathes (for example) that could handle a small V-8 car crankshaft would be entirely too small to handle 5-6 foot long V-12 aircraft engine crankshaft. Casting cast iron is a different skill than casting aluminium.
 
The people most familiar with casting aluminum back then, other than engine companies, were washing machine and sewing machine makers. Many aluminum parts for WWII engines were cast by Singer and Maytag. Singer was familiar with precision machining of steel,too, and made many precision parts for engines and weapons in WWII. Even Tiffany Jewelers in Mew York City got into war material produciton. They made the gold-plated amuinum disks used in late war throat microphones for interplane chat in B-17's and B-24's.

So it wasn't just the British that diversified production of war material, the US did it, too.
 
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This makes a lot of sense. If we ignore the V-1650 GG V-12 aero-engine and just look at the GAA V-8 tank engine. This would explain how this high-tech engine was ready for production in Dec 41/Jan 42. I doubt Ford could have come up with this design form a clean sheet. This would point to inspiration from an existing design.

Just a guess. The Merlin inspired the GG which in turn, inspired the GAA.

If, (and this is a big if) The Henry Ford Museum can provide the test parameters used in the GG, I will attempt to reproduce them with my dyno run of the GAC Tank V-12.
 
Good luck!

When we tried something as simple as getting some prop pitch specs for a WWII 6-bladed club propeller from Hamilton Standard, we were told "These data were produced for and at the request of the US Army Air Force. Since you are not the USAAF, the data will not be transmitted in any fashion to you. They are the property of the USAAF."

Explaining to them that the USAAF was no longer in existence and the USAF didn't care (we even included a letter from the USAF to that effect on official USAF letterhead to that effect) in the least did not do any good and they simply ignored us going forward. We came up with our opwn pitch data and now use that prop to break in just-overhauled Allisons. It was easier than we thought. We simply chose a pitch and ran the Allison at break-in power, noted the rpm possible, and adjusted until we achieved the desitred rpm. That pitch works for all Allison model at break-in and results in rapid piston ring seating.

The companies these days are more worried about potential laibility if the restored equipment breaks in a test they can be shown to have helped with than they are about preserving a historic piece of equipment in running condition.
 
Running an engine at part RPM ( even 90%) or so solves a few problems and ripping the supercharger off solves a whole bunch more. Lowering the average pressure in the cylinders to a third ( or less) or what they were expecting from the airplane engine (for the GAA) certainly makes things a whole lot easier.

Chrysler started work on their IV-16 2200cubic engine in the summer of 1940, it didn't fly until the summer of 1945.

P&W started work on both the R-2800 "C" series engine and the R-4360 (used R-2800 cylinders) in 1940. The R-2800 "C" series doesn't see combat use until the fall of 1944 and a short History of the R-4360 is here.

http://www.enginehistory.org/P&W/R-4360/R-4360History.pdf
 

Understood. However, If I can get the test data. I'll add manifold pressure, using an external source to equal that used in the original tests. Of course this will only be done if tear down inspection and rebuild provides confidence in the mechanical integrity of the test engine.

BTW - Nice write up on the R4360! Love that engine!
 
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Ran into the same problem with Lockheed in obtaining the blueprints for the P-38. It took some time, but they finally sent them.
 
I only joined yesterday, and I haven't taken the time yet to go through all the posts on this thread, so I apologize in advance if I cover some ground already covered.

I agree with others that the US would not have adopted a foreign engine.

The USAAC dropped its support for the Curtiss V-1570 in 1932. I think it is reasonable to assume that if the Allison V-1710 had not come along Curtiss would have developed a new engine as they did when the D-12 came to the end of its functional development.

Even if Curtiss hadn't, as has been posted by many others in this thread, there were other manufacturers, such as Lycoming and Continental, that were already building aircraft engines that would have been more than willing to develop a new generation of engines back in the early 1930s that would have been fully developed by the beginning of WW2.

As it was, both Continental and Lycoming began development of hyper-engines under Army direction in the early 1930s. Continental built the O-1430 in 1938 and successfully tested it in 1939, which would have been too late for any production of any of the V-engined US aircraft (P-38, P-39, P-40, etc.). Likewise, Lycoming's O-1230 first flew in 1940.

Packard's last aircraft engine that I can find prior to the V-1650 Merlin was the experimental 5A-2500 of 1930 rated at 1500 hp. While the xA-2500 was an "old" engine dating back to 1924, it is possible that Packard may have continued development of aircraft engines if Allison had not emerged.

The emphasis on the hyper engine by the US Army greatly hampered the development of water-cooled in-line aircraft engines, in my opinion. The Army began working on the development of hyper-engines in 1932, the same year that they cut the funding of the Curtiss V-1570. The Allison V-1710, which flew in 1930, before the Army switched to researching hyper-engines, was the last US design of water-cooled in-line engine prior to WW2.
 
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The trouble was financing development. Few companies were willing to design and develop an engine purely on speculation without some idea or prospect of sizable orders. In the US only the army was interested in liquid cooled engines for most of the 1930s and the Army wasn't buying very many airplanes per year. This resulted in the "gap" in liquid cooled engine development.
The Army alone was not responsible for Curtiss dropping development of the V-1570, Curtiss had merged with Wright and found itself with 2 engine divisions competing against each other. The only real competition was P&W and Packard and Packard, in numbers produced, was pretty much small potatoes. The Navy's decision not to use anymore liquid cooled engines pretty much ended Packard's primary market. The death of Packard's head designer after the diesel diversion along with the depression pretty much finished off Packard during the early and mid 30s. Curtiss-Wright didn't think it was very profitable to compete with itself and bailed out of the liquid cooled business as the airlines weren't interested in liquid cooled engines and they were a bigger market than the Military.
Military contracts during the 30s were much different than today. Contracts spelled out each step and payment was only made upon successful completion of a test or task, and even then payment could be late (sometimes very late). If a test engine broke before the test was finished the Army (or Navy) not only didn't pay for repairs but didn't pay anything until the engine was repaired and completed the required test. During the depression this meant few companies were willing to get involved in development of large complicated engines just for the army.

The Allison did NOT fly in 1930, It first flew on Dec 14th, 1936 in a converted Consolidated A-11.
 

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