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Old 04-28-2012, 09:13 AM   #10 (permalink)
Join Date: Apr 2012
Location: MacDill AFB, FL
Posts: 10
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Thanked 3 Times in 2 Posts
Thumbs up R-3350 hear & using alky

-I did a little Googling on the 3350s, but not enough to realize they were fuel injected. I'm impressed at that: during WW2 only the Germans managed to mass produce fuel injected engines; I didn't realize we ever did. One thing that did pop up was an offshoot of the R-2800 development. It turns out that some bright machinists found a way to cut superfine cooling fins that allowed better air circulation. There were still a depressing number of B-29 crashes due to engine fires. Well, we had a war to fight. I wonder how many hours total & B-29 specific pilots & copilots had before shipping out.
-Yes, alky fueled engines have some advantages. I wonder what compression ratio he used? One problem, up to recently, was that the alky just ate up the rubber & neoprene fuel lines. That's why car manufacturers were/are against even 10/15% alky content in gasoline. The stuff is also hygroscopic. The super serious downside to alky is that, in general, one cannot see an alcohol fire. I worked in disaster management (what a euphemism) for a few years and the two biggest industrial problems we faced were chlorine leaks and alcohol filled tanker cars. Unless someone saws the grass burning under a tanker "we" had no idea there was a problem. One of our projects was to get temperature sensors mounted on tankers.
-RE: compression ratios. Boy, are we getting way off the original topic, whatever it was. One of the reasons that the so called dual-fuel (gas & propane/CNG) cars don't do so well on straight natural gas is that the comprssion ratio is too low. The natural gas has fewer BTUs per unit of energy (that didn't come out right, mea culpa) but the users don't want to go to high compression heads because it affects resale value. Dummies.
-Good info, Old Mech. I'm learning new stuff!! Thanks.

Christ, I simply don't know about the heat loss to the chamber. I know that water/methanol injection was used to temporarily cool cylinders and prevent detonation, but I don't know about the heat of a pure alky engine. One thing I did find out is that ethanol & methanol have only about 2/3 the BTUs per volume of gasoline, so it stands to reason that alky would burn cooler and the cylinder head would only produce (max) 2/3 the power but the engine had been designed to dissipate the heat from burning gasoline. On the other hand, I may have just opened my mouth & firmly inserted a 10 1/2 E foot.

Last edited by NVSmith; 04-28-2012 at 09:26 AM..
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