Freewheeling Engine


#1

What does the term “freewheeling” mean? How does it differ from a “non-freewheeling” engine


#2

I thing ‘freewheeling’ means an engine that, when you let off the gas, is not connected to the wheels. For example, if you are coasting down a hill, a freewheeling engine will not help slow the car.

Why do you ask?


#3

Some of the regulars on this forum refer to a non-interference engine design as a “freewheeler”. This would mean that if the timing belt fails, valve damage is not likely to occur. An interference engine, or perhaps “non-freewheeler” is likely to have valve damage in the event of a timing belt failure.

Could you tell us where you heard this term and in what context it was used? Right now, we are guessing.


#4

In your engine there is either a timing belt, a timing chain, or a timing gear set. Essentially, these keep the top half and the bottom half of the engine running in sync. If the belt/chain/gear breaks, the engine quits running. In a freewheeling engine, the top half and bottom half just spin and eventually stop. In a no-freewheeling, ot “interference” engine, the moving parts of the top and bottom (valves and pistons) can hit each other, resulting in major internal engine repair.


#5

Yep, there are two very different meanings for the term. Here’s description related to disengaging the engine:


#6

Hey Buck-My name is George and I’m the one who asked this question. I’m not a mechanic but I am studying for the ASE P2-Automobile Parts Specialist exam. I liked your answer to my question and I would like to know if you would be available to assist me by answering a few questions from time to time. If so, please email me directly @ aptwoap@yahoo.com.
Thanks for your help
George
Sacramento, Ca


#7

If you happen to pass the test it probably would be best not to let anyone know about it. Some here equate passing a test with the inability to do real work, for the record I do not happen to feel this way about the ASE’s, good luck.