P-47 versus FW-190

[XBe02Drvr]

I am not very sure why higher-octane fuel would cause issues, unless it was extra tetraethyl lead in the fuel.

In normal operation, using higher-octane or higher performance number fuel will not cause issues unless it is maybe from extra lead.

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.
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

 

[pinsog]

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

Ouch! What year did this happen?

 

[Peter Gunn]

It is kind of strange for Jutland.

You must be new here...

 

[XBe02Drvr]

Ouch! What year did this happen?

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!)
And despite this sorry experience, I still went ahead and weaselled my way through A&P school after I got out of the Navy.

 

[Clayton Magnet]

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.

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.

Edit: Disregard, I see that the test mentioned in the first post was in fact the same Dec 1943 test. I would assume that a 1945 P-47 would then fair even better

 

[MIflyer]

Yes, it sounded like a valve problem with the Ju-88. One exhaust manifold started blowing fire and smoke. What saved them wa sthat while they had been throttled back in economy cruise, fearing they would had to ditch, they figured it would be better to so closer to the coast and increased the power level to get there faster. the higher power level probably prevented the same thing from occurring to the other engine.

And anyone who has tried to operate a C-85 on 100LL can tell you about lead problems in the spark plugs and the valves. 100LL has three times the lead of 80/87.

 

[XBe02Drvr]

100LL has three times the lead of 80/87.

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.

 

[MIflyer]

One airport where I was a student, flying Cessna 150's and 152's, they resorted to idling at 1200 RPM while on the ground. This did a fine job of wearing out the brakes but did not eliminate the engine troubles. On my Private Pilot check ride the examiner had me do a touch and go on the short runway (not a good idea in any case) and when I pushed in the power the engine kind of balked and hiccuped, at which point he pulled back the throttle, stomped on the brakes, and said, "Okay, I'll give you your license! Take this thing back and have them clean the plugs!"

As for combat pilot versus test pilot, both have their advantages. When Tony Levier in a P-38 jumped those F4U's off of Oceanside, he did not know their leader was Joe Foss. And Tony and Joe then had a mid-air so I guess it was a draw.

 

[pinsog]

As for combat pilot versus test pilot, both have their advantages. When Tony Levier in a P-38 jumped those F4U's off of Oceanside, he did not know their leader was Joe Foss. And Tony and Joe then had a mid-air so I guess it was a draw.[/QUOTE]

I've never heard this story, could you tell the rest of it?

 

[MIflyer]

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."

 

[pinsog]

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."

THANK YOU!!!! (From everyone)

 

[swampyankee]

^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,

This would be hard to determine, as an experienced experimental (vs production) test pilot can get quite a lot out of an airplane, because they can be very good at poking around the edges of the envelope, to find out both where they are and how to safely operate there. The way this test is described, it would also seem that the skills of a combat pilot weren't relevant: the aircraft were performing largely planned maneuvers; they weren't doing anything like rat racing, so skills like tactical and situational awareness and marksmanship weren't involved.

I am, nonetheless, somewhat surprised at the result, especially as these tests were performed at an altitude where the P-47's turbocharging would not be beneficial. Maybe German aircraft designs truly weren't as good as advertised.

 

[swampyankee]

On Chuck Hawks' site there is (or was) a post by a pilot who flew both P-51s and P-47s in combat. The comparisons he had were interesting, and seemed to point to the answer to the question "was the P-47 or P-51 better?" to be "yes."

 

[SaparotRob]

Couldn't find that article. Do you have the link?

 

[pbehn]

Maybe German aircraft designs truly weren't as good as advertised.

The Me262 wasn't bad.

 

[Hardrada55]

Couldn't find that article. Do you have the link?

P-47 THUNDERBOLT

 

[SaparotRob]

P-47 THUNDERBOLT

Great link. Thanks!

 

[BobB]

The Iron Eagle's Last Flight
Go to the end of the article for two experienced P-47 pilots conducting a mock dogfight with a captured FW-190 and the FW performed well. They may have been evenly matched enough that pilot skill and tactical situation would determine the winner. I can't remember where but I've read a statement by an Army pilot who'd flown both P-47 and P-51 that the P51 was a Ferrari and the P-47 was a Buick Roadmaster. He then said "Which would you rather be driving in a demolition derby?"

 

[MIflyer]

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.

 

[glennasher]

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.

Dunn's main gripe with the Mustang was the tail-warning radars installed in later versions, which ruined it's handling, in his eyes. He didn't like the Air Force adding all kinds of "extraneous" crap on basically great aircraft. IIRC, the tail-warning radar was nearly 400 lbs., which would screw up COG and other important things, along with the extra fuel tank behind the pilot. I've got his book around here someplace.