What does "4 x 4" actually mean?

Sarge, am I safe in assuming that the 10 wheels were on three axles (duallies on the two rear axles) and the front axle was also driven? It wouldn’t be so much the number of wheels as the number of hubs. Someone mentioned that already, but I’m too tired to go back and find the comment.

Just out of curiosity, how many tranny speeds did the 2-1/2 ton trucks have?

sgtrock, two different examples, jeep and a 6x4 truck. Sorry, I didn’t make that clear.

the same mountainbike: Yes. Three driven axles making it a 6X6 in “Milspeak”. 5 speed M/T with 2 speed high/low transfer case. Did you use the M-274 “Mule” (skateboards) on the flight-line? 4X4 with 3 speed M/T and 2 speed high/low transfer case.

It's an engine not a motor? ....

Nice tirade. Nobody said it exists to this day as you put it. It was an example of what they taught (hammered into their brains) back in WWII- did you miss that part? It was a reference to military training in WORLD WAR II. My Dad was trained as an airplane ENGINE mechanic and they were quite adamant about making it clear that was the only acceptable reference to that component in the aircraft. (think rifle = gun as another example) People who used what the military considered slang terms were subjected to KP duty. Although it was a relatively brief period of his life, it had a lasting impression on him for his entire life. So much so that he was on us for using slang terms that to him were not correct terminology.

BTW- they had the term MOTOR back then too. But it was a description more about the fact it moved under power i.e. motored about e.g. motorboat, motorcycle, motorcar. It wasn’t used to describe the piece of equipment used to provide the motive action- which can be an internal combustion engine or electric motor. That’s why it’ll always be a motorcar regardless of what provides the motive action. Hence- Division of MOTOR vehicles…

TT, my post was as true in WWII as it is today. All of the companies, motor vehicle laws, regulatory agencies, dictionary definitions, and uses in my post were well established long before WWII ever started.

I don’t doubt that they taught your dad that. But whoever taught him that was as wrong in WWII as he would be today. And whoever taught your dad that must have had real problems at the motorpool. :smile:

By the way, there’s really not a whole lot you can tell me about military life… since I spent four years of my life in the military. And I’m well aware of the derivation of the word “motor”. Neither of these things have any relevance to the question at hand.

So a Motorcycle would be a 2x1, and a trike would be 3x2

And a sidecar m/c would be 3x1, except an Ural, 3x2.

TwinTurbo: My automotive repair mentor was also a WW2 aircraft mechanic and would only call an electric power-plant a motor. Same thing with my 10th grade auto shop teacher. I also have heard engine and motor interchanged all my life so I don’t see it as any big deal. I think all of TSM’s examples are valid but I can’t imagine him as a member of the Air Force referring to numbers 1 thru 8 B-52 power-plants as motors. In Army aviation all aircraft operator and maintenance manuals referred to aircraft power-plants as engines. I don’t recall ever seeing one but if operator/maintenance manuals exist for Fan, Ceiling I’m confident the power-plant would be referred to as the motor.

I can’t imagine him as a member of the Air Force referring to numbers 1 thru 8 B-52 power-plants as motors

You’d have had to really like peeling potatoes…
:wink:

Two 2X2’s:

http://www.segway.com/

I’m late to the party but to me an engine is a motor but a motor is not an engine. Motorized means mechanically assisted but it could be by an electric motor or an internal combustion engine. If you got an engine vehicle violation and were driving an electric car, the judge would have to let you off. Motor covers every mechanical propulsion device of which an engine is one of them.

At least in my mind anyway and if you want to sound precise. “This is my rifle, this is my gun . . .”

So a bicycle or motorcycle is a 2x1, and a unicycle a 1x1 :wink:

Sarge, BUFFs had turbines… jet engines to the uninitiated. Small aircraft typically had radial engines, simply called “radials”. WWII “heavies” had stacked radials. The B29 and I believe the B25 had seven cylinder radials stacked four deep… for 28 cylinders total. I’ve seen one hands-on.

The B36 had six 28 cylinder “pusher” radials with four small turbines to assist in takeoff. Each cylinder had two sparkplugs. Each depot maintenance required the changing of 28X2X6 (336) sparkplugs. I have a photo of myself sitting on the wheels of a gutted one.

I mostly like Bing’s description. All engines are motors, but not all motors are engines. That’s more technically correct. But, then jets are engines that provide motive force, and they aren’t referred to as motors!

The B29 had an 18 cylinder radial, and the B25 had a 14 cylinder radial. The Constellation had the 28 cylinder radial, I think.

You are right, texases. I stand corrected.
Now I’m wondering what the 28 cylinder stack I had my hands on actually came from. Maybe the Constellation.

"Six turning, four burning!"


Talking about nomenclature, I always wondered why JATO (jet-assisted takeoff) systems were called that, when they are actually rockets. I found out today.


JATO was invented pre-WWII. At the time, jet propulsion wasn’t a “thing,” and turbine engines were something you typically used with a boiler! At the time, a “jet” was simply something that produced motive force by a concentrated stream of high-energy exhaust. It wasn’t until later in that jets referred to air-breathers, and rockets to designs that carried their own oxidizer.

Good question Joe.
I guess it’s all semantics.

I wonder, if Chrysler’s turbine car had worked out, would it start getting called by car guys a “motor”? :wink:

the same mountainbike: Yesterday I watched an American Pickers re-run where a guy had a 28 cylinder from a C-119 Boxcar mounted on an engine stand with no propeller. He started and ran it for a few seconds. There is one at the Boeing Field museum (I drove there in my Jeep 4X4.) that you can walk around for a good look. Quite impressive. It’s easy to see why it’s nickname was the “corncob”. I just had a thought. Would the afterburner on a turbojet be considered an external combustion engine?

If you behind one in full AB on the flight deck of an aircraft carrier, you will be thinking external combustion as little droplets of burning jet fuel hits your skin, but most of the combustion is internal.

Yup, an afterburner is considered external combustion. The entire jet engine is.
Internal combustion engines contain their explosions and convert the energy into mechanical movement internally. External combustion engines do not contain the gas expansion due to combustion, they use the expanding gasses for thrust. An afterburner just adds another fuel and combustion stream to the main engine’s exhaust. The afterburner typically has about 43ms to ignite or the system will recycle itself to keep from blowing up. I was involved in the design of a sensor that sensed afterburner ignition.