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Just dont get parkson's like morgan shepardI hope I look as good when I'm 79.
Morgan doesnt even have his team anymore they went bust when the virus broke outUnfortunately, we don't get a choice.
R/WooshThe only wood I know of in an A6M5 Model 52 is the handle on the throttle. Everything else is aluminum or a small bit of steel in some areas (main landing gear and maybe a few things like engine mount and control cables), with some fabric on the control surfaces thrown in and maybe some other material for the instrument panel top cover. Maybe aluminum ... maybe not. There are standard cable pulleys of G10-type material and rubber seals and tires. But make no mistake, it is a metal airplane, reasonably well-built.
This ain't no paper airplane! It's a real, live warbird complete with a 2-row radial engine and a prop made from Hamilton-Standard drawings by Sumitomo for Mitsubishi / Nakajima.
The Planes of Fame Zero, number 61-120, is the 2,357th A6M5 off Nakajima's production line. it was delivered in May 1943 and was assigned to the Japanese Naval Air Corps on Honshu. It moved to Iwo Jima and was later assigned to Asilito Airfield on Saipan. On 18 June 1944, Alilito Airfield was captured by the U.S. Marines with a number of intact Zero fighters. They were shipped to NAS North Island in San Diego.
61-120 was ferried to Patuxent River, Maryland on 23 Aug 1944 for use in the 1944 Fighter Conference flyoff, during which it was flown by Charles Lindberg, among others. It was ferried back to Dan Diego on 11 Jan 1945 where front line pilots were given a chance to fly it. Altogether, 61-120 logged some 190 hours of flying time before being declared surplus after the war. In 1950 it was acquired by the Museum. it was restored in 1978 with help from both Mitsubishi and Nakajima (now called Fuji Heavy Industries ... today they sell us Subarus).
The J2M had a wider cross section than all the R-2800 engined fighters. However, it possessed an aerodynamically clean nose section but I think this attribute was mostly nullified by the extra wide airframe. But then again, the wing section looks thinner than those found on F6F and F4U and similar to the P-47 (concerning T/C).The J2M likely has such a large cockpit because the radial engine is much bigger than a Sakae, but I just don't know the actual reason the cockpit is so large
1300L?using aviation contact cement
Getting around 1,900hp on less than 100 Octane fuel and that displacement is genuinely impressive to me, even with the Water Injection. The R-2600s maybe could run that much later war, but that's with American factories and fuel. Obviously, the R-2800 was making 2,000hp years earlier, but that's again with US factories and a MUCH higher displacement.If Wiki is correct the Homare was a 2187 cu in engine, It already used a rather high compression ratio in the cylinders, which may have helped cruise settings but hurt max power settings.
The main problem with air cooled aircraft engines is getting rid of the heat.
The water alcohol helps with this in several ways, one is as an internal coolant that absorbs some of the heat and carries it out the exhaust. another way is by lowering the peak temperatures in the cylinder.
I followed everything you wrote except why higher compression may help in cruise but hurt max power. Is that do to cruise power being close to max power in a higher compression example or is it do to heat rise?
Cheers,
Biff
Greg,Hi Bifff15.
You can only compress gasoline so much until it detonates from either pressure, temperature, or both. The ONLY reason you can run 140" MAP on a racing "Merlin" (not really a Merlin) at Reno is because the compression ratio (CR) is about 5.0 : 1. They'd try 4.0 : 1 if they could make it start.
If the CR is 6.0 / 6.5 : 1 as ina stock engine, you cannot get to 140", even with 150 PN fuel. It detonates first. You could maybe get to 80" / 90" max, and then you'd be right at the detonation limit.
I suppose it's no coincidence those are the quoted manifold pressure limits on War Emergency Power for the V-1650-9. Granted, the -9 uses Water Injection, which I would ASSUME changes those numbers, but the basic principle remainsHi Bifff15.
You can only compress gasoline so much until it detonates from either pressure, temperature, or both. The ONLY reason you can run 140" MAP on a racing "Merlin" (not really a Merlin) at Reno is because the compression ratio (CR) is about 5.0 : 1. They'd try 4.0 : 1 if they could make it start.
If the CR is 6.0 / 6.5 : 1 as ina stock engine, you cannot get to 140", even with 150 PN fuel. It detonates first. You could maybe get to 80" / 90" max, and then you'd be right at the detonation limit.
I will give this one a try.What I don't get is why higher compression will help at cruise but hurt at full power or vice versa.
Okay, let me see if I understand. The lower CR allows more fuel / air to be pushed in via the supercharger / turbo. With higher CR (too much pressure in the combustion chamber) the supercharger/ turbo is unable to push more in due to "no room in the combustion chamber "?I will give this one a try.
With higher compression you get more power from each pound of fuel burned.
The cylinder peak pressure will be higher and thus the average pressure (or mean pressure) acting on the piston crown will be higher.
But there is a limit to the peak pressure, that is a combination of the intake manifold pressure and the compression ratio.
With a lower compression ratio you can use more boost which allows you to cram more fuel and air into the cylinder for each firing cycle. You get more total power but you don't get the same power per pound of fuel burned.
Max Cruise for a Merlin was around 2650-2700rpm at 7-8lbs of boost (US and British didn't always rate them the same.)
Range cruise could be a lot lower.
The Merlin ran at 6 to 1 compression unless experimental?
The Allison ran 6.65 compression ratio and got about 8-10% more power at similar rpm and boost (cruising). There were a few other differences.
A few late model Allisons were made with 6.0 compression ratio to get more power (higher boost) while sacrificing a bit of economy.
Boost from increased compression was not linear.
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