Sea Fury "Hood Scoops"

[Unregistered]

Re: Sea Fury "Hood Scoops"

The Sea Fury stock engine is a Bristol Centaurus. It uses an "updraft" carburetor (like a Merlin) which sucks air in on the bottom. The stock intake splits below the carb and goes to intakes on the wing roots, the left side one being just inboard of the oil cooler inlet.

Then people started putting R-3350s and R4360s in the Sea Fury- those engines use downdraft carburetors with the air intake on TOP, so to hook up to a stock Sea Fury induction system there has to be a complete 180-degree turn in the intake trunking IN ADDITION to the split and other turns needed to get to the wing-root intakes, which reduces the pressure at the carb. Dreadnought (I think) was the first to use the cowl-top scoop with the inlet on the leading edge of the cowl, and it worked well. Only a 90-degree bend in the intake trunking, no "Y" in the trunking, good ram pressure, and no other twists and turns. Mike Brown tried a Skyraider-style cowl top intake (set back from the nose, with inlet guide vanes, directly over the carburetor) on September Fury, but the nose seemed eliminate the wanted ram pressure increase and he switched to a Dreadnought-style scoop. Spirit of Texas added the Dreadnought-style cowl scoop a few years ago. The other nice thing the cowl scoops allow is for the wing-root intakes to be covered, cleaning up the air flow at the wing roots.

The Centaurus doesn't have a carb at all, it's fuel injected and the air intakes are located on both sides of the blower section so theres a lot less turns that the air has to make compaired the way the 3350 is set up on the sea fury. The scoops on 232 and Dread are "enginered" scoops, designed to get the best ram rise and efficeny for the engines. The scoop on Spirit of Texas is just a straight rectangular duct and is not nearly as effective as dread's and 232's. Dread has seen 80 inches out of the engine with the scoop and 232 is right around there as well, where dawson gets about 62 given the 3350-26 doesn't put out the power the -93 and 4360-63 do. The other -26 powered seafurys only get about 56 inches so it does help but is not as good as it could be. A scoop simular to 232's would really help the bear a lot. I've heard on a good day with nitros they might see 68 inches so even though you would give up visibility you would get some good power.

**admin note: Please sign posts with at least a first name**

[Wilnit]

Re: Sea Fury "Hood Scoops"

I didn't think that it was last year that Riff Raff tried the Skyraider scoop. It seems like it was longer than that because I thought it blew off and did damage to the canopy and tail.

[John]

Re: Sea Fury "Hood Scoops"

This is interesting. It must be the long ducts are more effective for ram rise
than the short. Or is it more that the intake is right up at the nose where the dynamic pressure is greatest?

[MustangFan]

Re: Sea Fury "Hood Scoops"

Anyone have a pic of Lyle's Bearcat with the scoop on it? I've love to see just what that looked like...

[speeddemon]

Re: Sea Fury "Hood Scoops"

Anyone have a pic of Lyle's Bearcat with the scoop on it? I've love to see just what that looked like...

Go look at Scotty G's site in the Photo Galleries. Look in the Rare Bear gallery. There are at least three shots of it.

[Unregistered]

Re: Sea Fury "Hood Scoops"

This is interesting. It must be the long ducts are more effective for ram rise
than the short. Or is it more that the intake is right up at the nose where the dynamic pressure is greatest?

Dread's and 232's scoops are efficient because they aren't just a staight duct, they diverge just past the opening to increase the pressure of the air then slow the air down to make the turn down to the carb or air metering unit with as little disruption as possible and then speed it up again as it enters the engine, and the inlet size are optimal for the best effency throughout their speed range that they fly not just the top end. More than just long ducts and having the opening at the area of greatest dynamic pressure.

CW

[MustangFan]

Re: Sea Fury "Hood Scoops"

speed - Thanks for the info. I like that shot of Lyle taxiing with his head almost outside the canopy..probably trying to see over that hood scoop!

[speeddemon]

Re: Sea Fury "Hood Scoops"

speed - Thanks for the info. I like that shot of Lyle taxiing with his head almost outside the canopy..probably trying to see over that hood scoop!

Yeah, there is a similar picture in a book on the Unlimiteds that Don Berliner put out back in 1991....except in that shot, it is a side view of Lyle taxiing past, and he is literally standing up in the cockpit to see ahead.

[Unregistered]

Re: Sea Fury "Hood Scoops"

Bell Cobra IV doesn't stick his head in here much anymore, but he might have some good insight on how 'well' it worked, and such.

Speeddemon,
BellCobraIV was last seen by his alter-ego riding down the ramp with the late Dave Zeuschel, and Randy Scoville on a tug, going down to see the Me-209v1. It seems that too many unruffled feathers by some of the thinner skinned. finally won out and silenced the opiniated little *#@$, However he seemed happier to talk with. And says he has been doing a good bit of Sim flying and is current in quite a few sim aircraft, The Fw190 seems to be his favorite. He said it would be OK if I came around and talked some tech occaisonally, but that I should not pretend to know too much. The scoop over the nose on the Bear in 1976 was good idea but porly executed, that version would have surely failed structurally and no testing results were ever obtained regarding it's function.
John Slack

[speeddemon]

Re: Sea Fury "Hood Scoops"

Speeddemon,
BellCobraIV was last seen by his alter-ego riding down the ramp with the late Dave Zeuschel, and Randy Scoville on a tug, going down to see the Me-209v1. It seems that too many unruffled feathers by some of the thinner skinned. finally won out and silenced the opiniated little *#@$, However he seemed happier to talk with. And says he has been doing a good bit of Sim flying and is current in quite a few sim aircraft, The Fw190 seems to be his favorite. He said it would be OK if I came around and talked some tech occaisonally, but that I should not pretend to know too much. The scoop over the nose on the Bear in 1976 was good idea but porly executed, that version would have surely failed structurally and no testing results were ever obtained regarding it's function.
John Slack

John, be sure to say 'hi' to that 'opinionated little *#@$' the next time you see him. Maybe he can pass my regards on to Z and Scoville. He never ruffled my feathers...but hey, that's just me. Hacker and I were looking for you at Reno, but with The Doctor out of commission, I didn't know if you were even going to be there or not.

Thanks for the insight on the scoop.

BTW...can you log that sim flying in the book?

[Wild Bill Kelso]

Re: Sea Fury "Hood Scoops"

Yeah, there is a similar picture in a book on the Unlimiteds that Don Berliner put out back in 1991....except in that shot, it is a side view of Lyle taxiing past, and he is literally standing up in the cockpit to see ahead.

I think Lyle is so tall he can sit on top of the seat and STILL reach the rudder pedals. I always thought an articulating seat that pushed the pilot up and forward would be good for some of these airplanes.

[Unregistered]

Re: Sea Fury "Hood Scoops"

For Lyle to look over the nose on the Bear, all you have to do is take your toes hook them underneath the pedals, and pull back shortening them up. This makes it easier to see over the nose of the beast. Also there are foot operated levers that allow the pedals to extend back out. this not advised in flight but when on the ground you can visually the rudder to make sure they are both set to the same length. Over the shoulder look. Lyle Flew the Bear like nobody else ever did, when he was in it he owned not just it, but everything around it. One of my favorite recollections was the Qualifying run at Hamilton, Lyle had run the airplane hard enough to earn a top three qualifying spot, he pulled off the course, and since the venue was a first time effort asked if they had a time for him. Race control responded they did not know he was on the clock. I listened on the radio as he dressed them down for missing his time and allowing him to beat on the engine for nothing! Then he snapped back to the course, wicked it up further and said "time this one". Setting the fastest Qual lap. For a team that had been struggling for eight long years it was a gelling moment. Lyle was back on game, the Bear was working good, The crew had given him a mount that was ready in every way. The rest of that weekend continued on with a couple more recollections, The next best was Lyle blowing the turn and starting out over the bay, looking over to see Tiger pulling out in the opposite direction. (some Pylons were on boats, one had moved) I have video at home of the pass when Lyle Caught up to Tiger, You can hear Lyle Call to Tiger that he is moving past him, And you can hear Tiger say "Right" rather dryly. But pass him he did. And for the next four years he never looked back! For those of you that missed it, watching Lyle Fly made it all the late night work worth it. Don't get me wrong this is not a put down of John Penney, John Did a fine job. but Lyle is the master. A final case in point, Mojave 1975, The pace plane says Gentlemen you have a race and two bearcats pullout from the field and run a race that some could describe as a good film for formation training, lap after lap of consistent same spot flying. Of course ultimately they both lost to the very incosistent and rather wild but very darn fast Miss Candace With the first mighty Zeuschel Bullet. Alas time cannot rewind.
John Slack

[John]

Re: Sea Fury "Hood Scoops"

I think Lyle is so tall he can sit on top of the seat and STILL reach the rudder pedals. I always thought an articulating seat that pushed the pilot up and forward would be good for some of these airplanes.

Maybe they could acquire an old seat out the XFY-1 Pogo, then they'd be
happy campers!

Ha! Just teasing ya there FNG

[440_Magnum]

Re: Sea Fury "Hood Scoops"

Speeddemon,
BellCobraIV was last seen by his alter-ego riding down the ramp with the late Dave Zeuschel, and Randy Scoville on a tug, going down to see the Me-209v1. It seems that too many unruffled feathers by some of the thinner skinned. finally won out and silenced the opiniated little *#@$,
John Slack

Ah, nuts to the thin-skinned.

He lives!

[speeddemon]

Wow!

The scoop over the nose on the Bear in 1976 was good idea but porly executed, that version would have surely failed structurally and no testing results were ever obtained regarding it's function.

I found an interesting photo last night. The funny thing is, it is a picture I've looked at hundreds of times over the years, but I just didn't 'see' what I was looking at. In the '77-'78 Racing Planes & Air Races by Dusty Carter, there is a picture of the Bear at Mojave '76 on it's ill-fated qualifying run. It is almost a head-on shot from out at the pylons.

In the above quote, BellCobraIV states that the scoop was poorly executed and would surely have failed. Now, in the past, there has been plenty of discussions on this site about the torque that these race motors put out, and how it 'twists' the engine cowling--very noticeable in photos from out at the pylons, right?

This thread originally talked about hood scoops on the Sea Furies. And someone please correct me if I'm wrong, but on all of the Furies with hood scoops, the scoop itself is only as long as the cowling is. On the modification that was made to the Bear in '76, the scoop extended well past the back end of the cowling, and was faired in to the upper fuselage, just in front of the windscreen. This necessitated that the scoop actually be in two pieces, to compensate for the twist of the engine torque.

Well, in the picture I looked at last night, this is very obviously shown. Lyle is running at high power, and the engine cowling is twisted several degrees to the left. What hadn't really sunk in before was that it offsets the scoop too...and there is a HUGE gap on the right hand side of the scoop...it must be a good six inches 'offset'...between where the scoop is mounted on the cowling, and where the back half is faired in to the fuselage.

Not only would this have cut down on the amount of ram air that was going into the carb, but it also would have been 'disturbed' air, because of the separation between the two halves of the scoop. And THIS is obviously where that thing would have failed. Scary!

I put a lot of stock in what BCIV has to say anyhow, but this was just a huge exclamation point to his statement.