RR Merlin is unreliable
- Thread starter Peg Leg Pom
- Start date
The test Mule was supposedly run up to 1800HP, on a Ford developed 2 stage turbocharger, with Bosch fuel injection. GAAs with the governor disconnected could rev well past 3200, with official redline at 2800.
For hydroplane racing postwar, GAA ran 2200HP at over 4800rpm for what you could call, WEP. A lot of modifications, like any race engine. 3600HP on alcohol with 34 pound boost.
Most WWII superchargers rarely ran over 15psi
How many R2800 engines did Ford produce in 1942 and when did they go into service. Production isnt service it takes 6 months to a year before an engine flies in a combat zone.
A V8 tank engine with no blower isnt a Fighter engine. The supercharger is as important and in many ways harder to build than the engine when you get to two stages, two speeds, intercoolers and gadgets like ADI or Nitro.
I'll say it again no engine builder in the WWII era went from first sketches to thousands of in service fighting the enemy reliable engine in less than 3 years. P&W took 3 years from first sketch to a flying engine in peacetime but then spent another year or so getting the bugs out of it to make a production worthy single stage A series engine. The B series didnt really arrive get going till mid 42 on. The C series was 1944 on I believe but I havent checked.
Thank for the feedback, folks.
The supercharger thingy is interesting, especially if it was really a 2-stage turbocharger. Meaning there is no engine-stage supercharger (would've counted as 3-stage supercharging then)? Though, having fuel injection means that engine-stage S/C does not need to be there to 'mix' the air with fuel, and saves plenty of power to be used by the prop. Goes without a question that I'd love to see some pics/schematics, but I guess I'm not the only one.
Re. the boost - the +34 psi boost is very believable when engine is supercharged in one or another way, water-alcohol is obviously needed. Going at 4800 rpm (!!!) would be over-revving - WER points to over-boosting.
The Merlin went above +15 psi from early 1942 on, once 100/130 grade fuel is available.
Postwar some RR engineers decided to see just how far they could push a Merlin 100 series with Nitrous before it went bang. They got it to +72psi and 3300rpm and managed to hold it for about 3 minutes before the Supercharger ate itself. Shows how things developed in 5 years when a 1940 Merlin III would have probably melted at +20psi.
It was probaably the water-alcohol, not Nitrous, used for achieveing high manifold pressure?
Ford's production is listed in the pic, also from Nash Kelvinator for a good measure (though that is plenty late for this topic).
The R-2800-5 and -27 went in the B-26, as well as -43, the -21 went in the P-47s (B, C and later D). We can recall that P-47B was a dog, problems-wise it was at least equivalent of the Hawker Typhoon in 1942. The -59 and -63 also went to the P-47D, the -31 went to the Ventura/Lexington, the -51 to the C-46.
Ford's production is listed in the pic, also from Nash Kelvinator for a good measure (though that is plenty late for this topic).
The R-2800-5 and -27 went in the B-26, as well as -43, the -21 went in the P-47s (B, C and later D). We can recall that P-47B was a dog, problems-wise it was at least equivalent of the Hawker Typhoon in 1942. The -59 and -63 also went to the P-47D, the -31 went to the Ventura/Lexington, the -51 to the C-46.
Given that R-R was able to achieve reliable performance from the R Series Schnieder Cup engines the odds of the Merlin being a failure is pretty low IMO. The Ford V-12 if ever put into production for aircraft use would of had several advantages in terms of production versus the Merlin or the V-1710. The V-1710 if it had been developed with good mechanical superchargers from the start would of been a much more effective aeroengine. Even Curtiss's Conqueror had potential far beyond what was developed. It was killed as much by the AACs insistance on a 300°F operating temperature as the Depression
Agreeed 100%.
US Army spent plenty of money and time chasing the "HP per cu in" wild geese. Had they just told the numerous US companies (Ford, Chrysler, Lycoming, Continental) to come out with a liquid cooled engine that can compete with current best engines, I'm sure that we'd see such powerful and reliable US engines ready for the ww2. So it depended on Allison, a small company of the admitedly big GM to come out with a workable if not great V-1710. The Army's insistence on turbos meant that engine-stage superchargers were small, if of decent design.
Conquereor was a too light engine, and not with some big displacement. Will not stand up well to the increase in RPM and manifold pressure.
The Conqueror was only 70 CID smaller than the Merlin. Of course it would of needed to be beefed up for more power. But it would of been great if available for armored vehicles in say 1941 or so. One wonders just what happened to any fixtures or tooling Curtiss had for the D-12 and V-1580. There were a number of lackluster engines around circa 1930s. The Hisso 12Y is one.
Fine stuff
Is that a closely-coupled turbocharger just behind the engine?
All I can say is that it sure looks like an impeller, but there's no more definitive data, except that the induction air scoop is below, and the intercooler air is on top.
Hispano 12Y was certainly a lackluster in 1940s, but not in 1930s. That French did not capitalized enough on the 12Y was because of other factors, unrelated to the 12Y itself.
Weights (Wikipedia for 1st 3 types):
- Conquerror: 350 kg
- Hisso 12Y-25: 475 kg
- Db 601A: 590 kg
- V-1710-33: 608 kg
- Merlin III: 624 kg
Weight figures giving far better cue to the engines strength, and hence the prospects for power. The Conqueror will never match the 12Y, let alone the V12 engines listed that weighted 600 kg or thereabouts. Just like the Liberty engine will never match Conqueror in power.
I'd agree that Conqueror makes plenty of sense as a basis for a tank engine, though.