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Radial Aircraft Engines

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SwampMatt

SwampMatt

Well-known member
My dad has a friend who recently aquired an old military base. They are excited because in one of the hangers there was an old bi-plane trainer that they are going to restore. If stuff like that is to be found, I asked if they could keep an eye out for some radial engines.

If one (or more) is found what are they worth? Assuming they are NOT working. I told him if they find any to offer him $500 for each motor. I briefly searched the web and did not find any for sale to get a comparison price.

And with the noise issue, is a radial motor still practical on an airboat anymore? I mean, is it even possible to BEGIN to quiet one of those beasts down?

Just in case anyone is not familiar with a radial engine, I found this really good image of one... It'd be cool if they found a building full of these things!
radial.jpg


matt.
 
Mood, an old radial would be worth good money to the right person ...
somebody who is resturing an old plane for example, but they're very heavy, noisy, and they'd need AV gas (and a lot of it) to run. I've only seen one on an airboat. You'd have to have an oil tank too because they're all dry-sump lubricated.

Cool engines though. I love to hear one run. Pratt & Whitney built an R4360 years ago that was amazing. It had 4 banks of 9 cylinders .... 36
in all. A sparkplug change (72 of them) took two men a minimum of 4 hours to do.

BF
 
I worked on the kc97 which had 4 of those engines on it and we had 4 jet bottles we hung on it for a little extra on takeoff. The spark plugs were platinum tipped and back then they cost 18 bucks each. The fuel was 145 octane. The airforce scrapped them because of fuel costs and parts availability. I belive the 4360 stood for horsepower. I had a piston out of one for years and used it for an ashtray at parties. They were sweet when they ran but they leaked so much oil that when we shut one down we had to be ready with huge fire extinguishers on wheels to put out the oil fires. We use dto drain a quart of fuel out of each wing tank each morning to check for condensation and if it was clean we saved it in a can and used it to race on the weekends mixing it with pump gas.

Many a day my job was changing spark plugs on one of those planes.

aww the memories

But to the main topic here. Mood the radial engines burn way more fuel than you can carry to be effective and it costs way more than is practical and the oil tank probably should hold about 10 gallons to be safe. Parts would kill you even if the preceeding items were no problem. Those pieces of history are just that, pieces of history, if you get one it is nice to look at and talk about but not very practical to use all the time. I had so much time on those planes that all I needed to get my A&E license was the welding part. Oh yeah and in case you didn't notice I run a car motor on my boat. The government couldn't afford to run them so I figured they had more money than I do and lots more people who are smarter at cost anylisis. just my thoughts ... but never quit dreamin it is still free and isn't taxable .. yet.
 
Mood, I have been around and worked on several radial powered air boats. At one time they could be had cheap, surplus out of Kelley AFB in Texas. The power to weight ratio is not there. There is a run that we we make that is 30 miles one way, the radial was a mule. It was a 20 ft. Airgator 7.5 wide.
 
Check this out from an old post:
"This is our first airboat. We got it back in the late 70's. It was a fiberglass Jabo 13' hull with a Lycoming R680 Radial engine, 300 HP at 2300 RPM. It would turn 2900 making about 375 HP. It would use 35 gal of gas and 5 qts of oil to go about 25 miles. The prop was off a Goodyear Blimp cut down from 80" to 72" variable pitch. The exhaust was on top and when the boat was running at night it would send a flame that would wrap around the inside of the guard. It sounded like a DC 3 airplane. The boat weighed 2200 lbs. with a full tank of gas. Couldn't afford to run the boat now. We used it for several years. We went riding every Sunday on the St. Johns River."
Click to expand...

95Web_radialboat.jpg
 
Very Cool, Rick .... thanks for the photo. The only other radial airboat I've ever seen is over at Keaton Beach, a few miles N. of Steinhattchee.
I've seen it hanging in a boat lift ..... next time I'm over that way I'll stop and talk with the owner just to hear it's history.

BF
 
There is one in Melbourne called the Memphis Bell it is parked behind a tranny shop. Unfortunately the owner died in an airboat accident and the boat has been sitting ever since.
 
Well, I've learned something new today. Looks like it is not worth the trouble because of the power-2-weight ratio. Not to mention the gas & oil consumption... and parts availability/serviceing ease etc.... but most of all.... if the exhaust spits out a flame that wraps around the cage... how can you muffle that?!!!? It'd be a boat that these days would be just too darn loud.

:::sigh::: I guess those days are gone, and those who got to see one of those engines in use are very lucky indeed.

Great photo Rick. I was sort of hoping to get two or three of those motors and trade them to my favorite airboat manufacturer in exchange for a hull. But if it was an AirGator, it sounds like he's already been there - done that.

The mechanical workings of those radial motors are just sexy to my mind. The romantic nostalgia is also just as appealing, and the RAW POWERFUL SOUND they make really touches my heart when I hear one flying overhead everyday towing an advertising banner. (I live near the in-town airport where they take off & land)

Oh well. Like Cntry says - They don't tax dreamin'!!!

:)

Thunder - I'd like to see that someday - Just to pay homage to the technology and maybe shed a tear for a parked and rusting boat.

matt.
 
I have a picture from the mid 80's of a 14ft. glass boat with a 7 or 9 cylinder radial on it from this area. The first time I heard it comind down the trail I thought that a plane was buzzing the sawgrass or in the process of crashing (hoping for a free 540 too :twisted: ). The sounds from that boat were plain radical and this was back in the day everyone with an aircraft motor had 8in. open stacks. I need to find that pic and post it up in my gallery.

Larry
 
Muffling them is pretty easy. You bend a manifold pipe that goes around the engine and all the stacks dump into it. Then your header pipes come out of that and into your muffler(s)

Check out this page, this guy is a top notch machinist. Very interesting learning about building a small Radial engine.

http://www.5bears.com/
 
The old continentals, lycomings, and the Pratt & Whitney are expensive, parts are scarce and expensive too. They are heavy for their power.

There is one radial that is light, powerful, and extremely reliable. It is the Russian Vendenyev M 14. It is a 620 cubic inch 9 cylinder radial. They range from 300 to 450 hp they are geared and supercharged. (that is prop shaft horsepower so there is no further loss in the reduction gear.) The engine turns 2900 but I believe the gear reduction is 1.5 to 1 which would turn the prop about 1930. I think they weigh about 500 complete.

If anyone is interested I can make a call and check those figures. They have been weighed locally.

They are around used in the 360 and 400 hp models. Prices vary, but it is not out of the question. They are quiet because they are geared. A muffler system would be easy.

A 600 hp auto engine loses about 37% in the reduction gear (I'm told) so that would be 378 at the prop shaft. I would guess the performance would be similiar.

vedeny5.jpg


specs:

http://www.steenaero.com/engine_m14p.cfm

Jim
 
Thunder, CC has my boat down in your neck of the woods for a little welding. I'll give ya' a call when I'm in town the next week or so and get directions to that tranny shop and have a look at the Memphis Belle. If she doesn't look like a total loss ..... ?

No one would want one of them for their everyday ride boat anymore, but how cool would it be to have one of these classics (restored) to take to an occasional get together! I think it might be a piece of history that's worth saving as long as ya' didn't have to mortgage the farm to fix it up. I'm already thinkin' about the rudder art. It could be the same as the artwork on the B-17 in the movie of the same name.


BF
 
I called that guy last year. I would suggest that you check the parts prices for that engine before you buy it. It will cost you a ton of money to get it going, if you can find the parts.



Jim
 
moodfood":g6d8otx5 said:
The mechanical workings of those radial motors are just sexy to my mind. The romantic nostalgia is also just as appealing, and the RAW POWERFUL SOUND they make really touches my heart when I hear one flying overhead everyday towing an advertising banner. (I live near the in-town airport where they take off & land)
Click to expand...

Matt you and I must be a lot alike. I had the fortune of seeing the Red Baron Pizza Squadron last month at the Heart of FLA Airshow in G'Ville. They brought tears to my eyes. Amazing to see and hear the old Stearmans doing loop after loop and hammerhead turns.
 
Matt and Red,

If you like the Stearman performance and sounds check out this site:

http://www.mohrbarnstorming.com/

John Mohr is probably the best Stearman pilot ever. He gets more out of a stock 220 Stearman than most can out of a 450.

There is a video with sound in the multimedia section. The file is very large though. You need high speed to download it. Sorry Red.

John landed his amphib here on the lake and nosed it into my yard. He was worried about my neighbors and the noise. I told him it was not a problem, I have great neighbors, they enjoyed the whole thing. They want him to come back.

Jim
 
Nearly 40 years ago now I flew a Piper Pawnee crop duster one summer for a little FBO up in Illinois. That old bird had a P&W 1340 on it
with a Hamilton-Standard prop. I wouldn't have told anyone at the time because I needed the money, but I would have flown that airplane for free. Nothing on this planet sounds like, or smells like an old radial.

Radial engines use a Master Rod ..... all of the connecting rods of all of the cylinders other than #1 are connected to a wide flange around the connecting rod on that one cylinder .... there wouldn't be enough room in the crankcase otherwise. Because of this arrangement, the cam timing is a science all it's own. Most of the rods on the other cylinders rotate in an elliptical motion, and that's what gives them their unique sound. A Harley sounds like it does for much the same reason .... the cylinders on a H-D are 62 degrees apart instead of something more obvious, and smoother, like 90 degrees.

BF
 
Thanks for postin' that great picture, Jim. A photo really is worth a thousand words. Isn't that a beautiful piece of machine work!! Wow.

The strangest radial I ever heard of was the Gnome engine from the 1st W.W. It had the prop attached to the cylinder/ crankcase assembly and the crankshaft was bolted solid to the firewall of the airplane ....... the cylinders spun around at the same speed as the prop!! It had a positive-loss oil system ..... oil was fed into it through the crankshaft and then slung out to the cylinders and valve gear by centrifugal force. They were said to be pretty reliable for their day and made a lot of torque because of the spinning mass of all of those cylinders. Throttle was fixed at wide open. The pilot used an ignition cut-out to taxi and land.

Ken
 
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