OT: adding water to fuel

Blowing down a supercharged engine means forcing extra unburned fuel and air through the cylinder until it runs out the exhaust valve. It's a matter of valve timing, and the purpose is to cool the cylinder head and the exhaust valve itself. It's very wasteful but it works.

The advanced timing I'm referring to is the static timing. With water injection, you can advance the timing, on an engine that's marginally high on compression or detonation tendency.

On some of the engines used late in WWII, the effective compression was high enough that the engines needed blowdown or water injection even with the highest octance fuel.

-- Ed Huntress

I hadn't heard that about Midway. We won there due to extreme good luck. There is a Torpedo Squadron 8 thread running on rec.aviation.military. (you think -this- group has whiny liberatics?)

Lindbergh went to Guadalcanal and New Guinea to teach the fighter pilots how to increase range by better engine management. First he had to convince them that 1600 RPM, a lean mixture and high manifold pressure wouldn't damage the crank bearings and leave them swimming with the sharks.

When he arrived the combat radius of a P-38 was 500 miles. When he left it was 900. The 5th AF wiped out the huge Jap air base at Hollandia by pretending to run low at the old distance until the base was packed with new planes.

=46rom CAA Aircraft Powerplant Handbook, Jan 1949, pp112-113:

The water-injection system uses water as a detonation surpressant rather than excess fuel. The rate at which water is injected is such that the total liquid (fuel and water) equals the total of fuel previously required to surpress detonation. ... While water is injected, the fuel-air mixture strength is reduced automatically to that giving "Best Power" and, if no change is made in manifold pressure, an immediate increase in power of 6 to 8 percent is obtained. The anti-detonant qualities of water are such that, in addition to the increased power obtainable at the normal take-off manifold pressure, the throttle can further be advanced and another 6 to 8 percent of power can be obtained by the additional manifold pressure."

Jim Wilkins

I don't believe it wa the battle of Midway but in general terms "the Air War in the Pacific". It was Charles Lindberg who developed the system of decreasing RPM and running the engines leaner then normal to increase the P-38's range. I believe that they shot down the aircraft carrying Admiral Yamamoto using this technique.

Bruce-in-Bangkok (correct email address for reply)

Thats! what I was remembering. Thanks for refreshing my memory.

Gunner

"Pax Americana is a philosophy. Hardly an empire. Making sure other people play nice and dont kill each other (and us) off in job lots is hardly empire building, particularly when you give them self determination under "play nice" rules.

Think of it as having your older brother knock the shit out of you for torturing the cat." Gunner

The heat coming off the radiator is a bigger issue than the exhaust, and there IS something that can be done about that. Lots of things actually - air shrouded injection is a start, and ceramic coatings make a significant difference. If somebody REALLY tried, there is a lot of efficiency that can be gained from a spark ignition 4 stroke.

That would be Charlie Lindburg, IIRC. Running lean of peak was one of his strategies - and on a fuel injected engine it is quite possible. On the "overpriced antique tractor engine" with the long wet manifold and bottom mounted carb mixture distribution is SO BAD you need to run rich of peak at power so your "worst case cyl" does not self destruct.

I missed the Staff meeting, but the Memos showed that Gunner Asch wrote on Sat, 15 Mar 2008 01:56:22 -0700 in rec.crafts.metalworking :

I know that post Korea, the Navy was supposed to have been "playing games" with the A-1 Skyraiders (What the Air Force knew as the "Sandy" in the SE Asia War games), doing just that sort of thing, figuring out the speed range trade offs of various power settings. Part of it was "you've got a lot of time to fly there, no sense flying in circles here to get to altitude." and other "small things."

tschus pyotr

-- pyotr filipivich "I had just been through hell and must have looked like death warmed over walking into the saloon, because when I asked the bartender whether they served zombies he said, ?Sure, what'll you have?'" from I Hear America Swinging by Peter DeVries

Every time you convert energy forms, you lose some energy. So, using energy to break water into H and O, is losing energy. Much better to skip all the inbetween steps.

Peoples eyes glow when they talk about non polluting hydrogen. But, it's hard to get them to figure out how you're gonna make that hydrogen. You can pump oil or methane out of the ground. You can mine coal. But I don't know of any hydrogen mines.

I do, but it's 93 million miles away.

Yep, and it's been afire for a long time. Even Red Adair wouldn't touch it.

Well, he could go at night.... :)

And then there's this:

And, Saudi Arabia owns it.

Not till they plant their flag on it for everyone to see.