FlagshipAZ
Topic Author
Posts: 3192
Joined: Sun Jan 28, 2001 12:40 am

The Engines Of The Spruce Goose

Tue Feb 25, 2003 11:46 am

Hi folks...
I remember hearing rumors that the 8 round motors of the HK-1 Hercules being fired up once a year while the bird was still in long-term storage at LGB harbor. Any truth to this rumor, or is it just urban legend? Also, does anyone here know what brand & model piston engines are installed on the Goose? How is this aircraft doing in Oregon nowadays...all reassembled again? All replies appreciated. Regards.
"Beer is living proof that God loves us and wants us to be happy." --Ben Franklin
 
IMissPiedmont
Posts: 6200
Joined: Wed May 23, 2001 12:58 pm

RE: The Engines Of The Spruce Goose

Tue Feb 25, 2003 2:00 pm

The engines are the P&W 4360 as on the B-50, C-124, B-36. C-97/B-377. etc.

It is not true that were started yearly.

The aircraft if fully assermbled and on display in Oregon.
The day you stop learning is the day you should die.
 
erj-145mech
Posts: 305
Joined: Tue Oct 02, 2001 4:21 am

RE: The Engines Of The Spruce Goose

Tue Feb 25, 2003 3:47 pm

Originally, Hughes wanted to use Lycoming XR-7755's, but Lyc couldn't get the bugs worked out in time. The original plan was to use four of the Lycomings, and it took 8 of the Pratts to come up with the right amount of power.

The 7755's were 36 cylinder corncobb behemoths, the rear two rows had water jackets and were water cooled. Not enough cooling air could get back there. When the engines were powered up in the test cells in Montoursville, where the plant is located, the resulting vibrations would knock china from hutch shelves. Lycoming engineers built a special test cell that used a series of criss crossing railroad ties to try to reduce the vibrations. I saw one when I was at the Lycoming factory in the late 70's, and talked with one of the engineers involved.
 
T prop
Posts: 909
Joined: Tue Apr 03, 2001 4:33 pm

RE: The Engines Of The Spruce Goose

Tue Feb 25, 2003 5:36 pm

Here's the big Lycoming.





T prop.

 
Buzz
Posts: 694
Joined: Sun Nov 21, 1999 11:44 pm

RE: The Engines Of The Spruce Goose

Tue Feb 25, 2003 11:48 pm

Hi FlagshipAZ, Buzz here. If you come to Portland Oregon, it's about an hour's drive SW to McMinnville airport (MMV) which is across the street from the Evergreen Museum. You can see the "barn" from several miles away when you fly in the area.
Engines and a few other parts are quite out of reach, but the Hughes HK-1 is assembled and they have a nice musueum there.
For more large engine stuff, try a web site www.enginehistory.org and see what the Aircraft Engine Historical Society has posted, it's interesting stuff.
g'day
 
broke
Posts: 1299
Joined: Wed Apr 24, 2002 8:04 pm

RE: The Engines Of The Spruce Goose

Wed Feb 26, 2003 2:19 am

The Air Force Museum at Dayton, Ohio has two displays that include the R-4360. One is the C-124, where one of the airplane's engines is uncowled. The cylinder heads are covered by sheet metal used to direct cooling air more efficiently over the cylinders. The last row of cylinders had a reputation of overheating more than any other row. This will give you a good idea of a typical engine installation.

The other exhibit is of a R-4360 mounted on a portable engine stand with the cylinder heads exposed. You can get a much closer look at the "corncob" and its accessory section which is mounted on the back of the engine.

In the big engine class, the museum also has a Wright R-3350 that has been partially cutaway so you can see the pistons, connecting rods, crankshaft, etc.
 
flyf15
Posts: 6633
Joined: Tue May 18, 1999 11:10 am

RE: The Engines Of The Spruce Goose

Wed Feb 26, 2003 5:26 am

What was the displacement and horsepower/torque of the 7755? That thing is enormus!
 
TomH
Posts: 950
Joined: Thu May 27, 1999 4:13 am

RE: The Engines Of The Spruce Goose

Wed Feb 26, 2003 9:42 am

According to Herschel Smith in "A History of Aircraft Piston Powerplants", the Lycoming XR7755 achieved 5,000 HP on test with a development goal of 7,000 HP. Smith alludes that there is one at Silver Hill.

 
IMissPiedmont
Posts: 6200
Joined: Wed May 23, 2001 12:58 pm

RE: The Engines Of The Spruce Goose

Wed Feb 26, 2003 2:15 pm

To add a bit to the post by Broke.

At the Pima Air Museum we have a 4360 cutaway that, when you press a button, turns. Quite impressive if you've never seen a radial in operation. I've watched people stand for an hour watching and trying to figure it out.

Visit us when in Tucson. Just walk on back to hanger 2 and see our small collection of engines. When was the last time you got to turn an RB-211 by hand and hear the wonderful clank?

ID the prop behind the desk and I will be eternally grateful, none of us can tell what aircraft it's from.
The day you stop learning is the day you should die.
 
FlagshipAZ
Topic Author
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Joined: Sun Jan 28, 2001 12:40 am

RE: The Engines Of The Spruce Goose

Wed Feb 26, 2003 11:28 pm

Thank you one & all, for your fantastic replies. I've heard that the R-4360 was also the main power plant on the original Flying Wing...the XB-35. Don't know if this is true or not. I'm certainly will be visiting the USAF Museum once again, and also the Pima Air Museum...have yet to visit that place. Thanks again, guys. Best regards.  Wink/being sarcastic
"Beer is living proof that God loves us and wants us to be happy." --Ben Franklin
 
411A
Posts: 1788
Joined: Mon Nov 12, 2001 10:34 am

RE: The Engines Of The Spruce Goose

Thu Feb 27, 2003 4:55 am

For those that may be unaware, the Pratt&Whitney R-4360 (Wasp Major) was developed specifically for the B36 (pusher design) and when the engines were used on other aircraft, the rear row (row four) ran very hot because, the cylinder row offset was the "wrong way 'round" for a tractor design, thus cooling air was difficult to get to those rear cylinders.
For the military, not a problem, unlimited budgets were available.
Civil designs were limited to the Stratocruiser, which burned approximately 600 gals/hr (fuel) and 8 gals/hr (oil).
Somewhat like the DC7, range was often limited by oil quantity.
 
timz
Posts: 6081
Joined: Fri Sep 17, 1999 7:43 am

The Lycoming

Thu Feb 27, 2003 11:06 am

Gunston says the 7755 had 36 cylinders 6 3/8 by 6 3/4-- so that's 7756 cubic inches.

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