Engine Rotation Questions
- Thread starter Shel_B
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Good question. I also wondered about that. I know the late, great NASCAR mechanic Smokey Yunick built a reverse rotation engine, (counterclockwise), that would aid with opposite torque, to help the drivers turn left. Instead of having to fight it.
But I believe NASCAR banned it because it wasn't, "factory available". I often wondered if in NASCAR, if a driver spun out and didn't get the clutch depressed in time, and the engine started to reverse rotate, (rolling backwards at high speed while in gear), if that could screw up the engine internally? I had heard that it could, but not exactly how.
But I believe NASCAR banned it because it wasn't, "factory available". I often wondered if in NASCAR, if a driver spun out and didn't get the clutch depressed in time, and the engine started to reverse rotate, (rolling backwards at high speed while in gear), if that could screw up the engine internally? I had heard that it could, but not exactly how.
FWIW the F22B2 engine in my old Accord spins CCW when viewed from the crankshaft pulley end. All the F series engines are this way along with some other Honda series. Why, I have no real idea. The only thing that's significantly different is that the transmission is on the right side rather than the left.
Older Hondas rotate the other way.
When I was a kid I had a 2-stroke model airplane engine that would fire and run in reverse every once in awhile. Propeller spinning backwards won’t work for flight. Either stall it out or wait for the fuel to run out.
A 2008 thread about a similar question.
When I was a kid I had a 2-stroke model airplane engine that would fire and run in reverse every once in awhile. Propeller spinning backwards won’t work for flight. Either stall it out or wait for the fuel to run out.
A 2008 thread about a similar question.
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A good article about some of the things Smokey did in NASCAR.
www.motortrend.com
"No rule said that an engine had to rotate in a certain direction, so I'd reverse the rotation and have all the torque loading on the left side of the car. Really, all I had to do was make up different cams, then turn the rear end upside down and reweld the spring perches. Not even my own drivers ever knew about that one."
Smokey Tells All - Smokey's Vault - Circle Track Magazine
Legendary racer Smokey Yunick discusses thirty years of fun, games, and playing fast and loose with the rules - Circle Track Magazine
"No rule said that an engine had to rotate in a certain direction, so I'd reverse the rotation and have all the torque loading on the left side of the car. Really, all I had to do was make up different cams, then turn the rear end upside down and reweld the spring perches. Not even my own drivers ever knew about that one."
Most do go clockwise. Honda in the past went ccw. Honda put there engines in the other side.
They can be designed to rotate in either direction. A circle is a circle in either direction.
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I read somewhere that back in they day with twin inboards - which were just ford or chevy engines - would be made to run opposite directions - so one screw was turning one way and one the other. Not sure why.
Detroit diesels would fire off and run backwards if you lugged them down right to the point they stalled and kicked in the clutch at the exact right moment!
I used to bump start my 2-stroke motorcycle going backwards in my youth. That was fun.
I know some 60's Oldsmobile V8, early Corvair, some Honda and a few other engines were CCW, I have heard about CCW marine engines.
Corvair engines rotated CCW, which makes sense given rear engine design.
Many multi-engine propeller airplanes have counter rotating piston engines. This helps mitigate the effects of torque, P-factor, and slip-stream. The downward sweep of the propellers are inboard, this also help reduce the effect of P-factor.
When a multi-engine doesn't have counter rotating engines, the engine with the downward sweep of the propeller that is outboard is called the "most critical engine" because P-factor has the most effect furthest from the center line of the the airplane. The joke with a two engine airplane is that which ever engine is still running is the most critical engine.
When a multi-engine doesn't have counter rotating engines, the engine with the downward sweep of the propeller that is outboard is called the "most critical engine" because P-factor has the most effect furthest from the center line of the the airplane. The joke with a two engine airplane is that which ever engine is still running is the most critical engine.
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Yes, but this was back when Nascar was Nascar, when the France family executives were actual racing people. Now the France's are just a bunch of spoiled kids. I don't think I have watched a race in a decade or more.A good article about some of the things Smokey did in NASCAR.
Smokey Tells All - Smokey's Vault - Circle Track Magazine
Legendary racer Smokey Yunick discusses thirty years of fun, games, and playing fast and loose with the rules - Circle Track Magazine
"No rule said that an engine had to rotate in a certain direction, so I'd reverse the rotation and have all the torque loading on the left side of the car. Really, all I had to do was make up different cams, then turn the rear end upside down and reweld the spring perches. Not even my own drivers ever knew about that one."
A "reverse cam kit" was available to install V6 engines (Buick, as I recall) in the rear seat of Corvairs.
I don't watch much either. I loved to listen to Yunick. He once said that 80% of the rules in NASCAR were because of him.
Yes. Too much torque will make the boat list under power.
Many boat and aircraft engines are available in CW and CCW rotation, and many formerly Eastern Bloc aircraft engines were CCW rotation as standard.
Since at least 2003 2 stroke snowmobiles reverse the engine to provide reverse track motion. Push the button and engine stops and reverses, push it again and same process just restarting in the forward direction. CVT transmissions exclusively.
