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I am not very sure why higher-octane fuel would cause issues, unless it was extra tetraethyl lead in the fuel.
Right on! And the issue is less about plug fouling than it is about valve burning. Highly leaded fuels have an additive (don't remember the name, but it's one of those multi-syllable chemical monstrosities) which is designed to keep the lead in suspension above a certain temperature, so it doesn't deposit on internal surfaces. When this fuel is used in a lower octane engine which operates at lower CHTs the coolest parts in the combustion chamber, the intake valves and their seats, can accumulate little globules of lead which prevent them from seating properly, thus allowing blowby on the power stroke. This leads to burned valves, unhappy intake systems, reduced power, and eventual failure.In normal operation, using higher-octane or higher performance number fuel will not cause issues unless it is maybe from extra lead.
Ouch! What year did this happen?Right on! And the issue is less about plug fouling than it is about valve burning. Highly leaded fuels have an additive (don't remember the name, but it's one of those multi-syllable chemical monstrosities) which is designed to keep the lead in suspension above a certain temperature, so it doesn't deposit on internal surfaces. When this fuel is used in a lower octane engine which operates at lower CHTs the coolest parts in the combustion chamber, the intake valves and their seats, can accumulate little globules of lead which prevent them from seating properly and allowing blowby on the power stroke. This leads to burned valves, unhappy intake systems, reduced power, and eventual failure.
I learned this the hard way when I flew the flying club's T34 (box stock O470-4 80 octane engine) up to Tamiami and came back with a load of 100/130 that the FBO insisted was the correct fuel for the plane and wouldn't take no for an answer.(Young and foolish, what did I know?) The next pilot downed the plane for a rough running engine, and I was assigned as mechanic's helper, gofer, and general knuckle buster while a top overhaul was conducted on the two front cylinders. I got to pay full retail for the load of gas, the mechanic's time, the equivalent civilian price for the parts (we got them free from NavSup) and remained grounded and apprentice knuckle buster until I could come up with the cash to pay it all off. Lesson not soon forgotten.
Cheers,
Wes
1971 or 72, I forget which. It's in my logbook, I can look it up. Back story: the FBO where I bought the gas was home base for a pair of airshow performer T34As (Air Force version) which had been up-engined to TSIO520 Continentals, and did legitimately use 100 octane. The Line Boss was convinced that was standard for all T34s and filled me full of scary stories of engine detonation from low octane fuel. (He didn't actually try to sell me any Flight Line or Prop Wash, however!)Ouch! What year did this happen?
The first post was related to how much BETTER a late model "improved" P-47 got, when compared against the same Fw 190. Which would suggest that the older models didn't fair as well. A 1945 P-47 was a different beast than a 1943 P-47, but they probably used the same Fw 190 as from the December 1943 test.I have not seen other evaluations of P-47 versus Fw 190 myself, so I can't say. The first post says a LOT, but is not definitive due to the disparity in pilot experience.
Righto, old chap. Now just imagine the old pre-100LL, 100/130 gas in an 80 octane engine. When the flight school I was working for couldn't get 80 octane anymore we started having all kinds of troubles with our O200 and O360 Continentals. Oddly enough our O360 Lycomings seemed to be immune.100LL has three times the lead of 80/87.
THANK YOU!!!! (From everyone)I heard it from Tony Levier back around 1981. It is already on here, I believe, under "Tony's Midair"
Well, I checked and I can't find it here. I did find where I had written it down and I will post it in "Stories."
^Maybe partly, based on the description of the pilots, one with 17 months of combat experience, surprisingly flying the P-47, the other with none flying combat simulations. Without more background info IMHO it seems that the P-47 pilot had some advantages,
The Me262 wasn't bad.Maybe German aircraft designs truly weren't as good as advertised.
Great link. Thanks!
I think it was William Dunn that wrote a book about his experiences in WWII with the RAF and then the USAAF. He claimed to be the first American Ace in WWII, although if so apparently by only a few minutes.
He loved the Spitfire and came to like the P-47 but never really cared much for the P-51, which I think is rather odd. You would expect it to be the opposite, getting in a P-51 would be like being back in the Spitfire, but even better, as most described it.