Auto Transmission Mechanics Question

[H311RA151N]

Ive watched that exact video before. Thats really cool.

This is off topic but its pretty neat IMO. Plus it comes up with the video you posted. I like the solid blue flames coming from the headers.

[RyanD]

put that in a cb. "fuck yo mustang!"

anyway. i see what you all are saying about the free revving thing and i can understand you all sayng what the engine was meant to do what what CAN it do? no the F22 was not ment to rev but it revs just as fast when you down shift on the freeway comming up in speed or slowing down auto or manual

[oyajicool]

im thinking back to aircraft engines which fundamentaly they are the same. engines are engines (except jet engines, that shit is crazy)

when you feather the prop there is little to no resistance on the engine. it still runs and it aint bad for it. but when you put the prop to full pitch it creates A LOT more load on the engine. and yet they are fine?

Here read about feathering, below, Ryan.
http://en.wikipedia.org/wiki/Propell...ft)#Feathering

Read that, see the photo and think what kind of loading the engine have to run against if that engine was running. Compare that with your statement, above in red.

[oyajicool]

Now on to the total Honda Accord CB7 aspect of this. Honda did not design any part of the hundreds of components of the F22A with free revving in mind. Period. It’s meant to be used under load from 900-1100 on up to 6500 RPM. As advanced as our engines are, I’m 100% sure there is negative effects to free revving an F22A simply because it’s being used to do something it was not designed to do.

Engines are designed to be operated within the specified RPMs. I'm 100% sure those engineers didn't specifically had idea of which mode the engine to be operated on, load or no load.

On any given engines on any given RPM, the more load the engine is placed, the more engine wear will be the result as opposed to the engine with no load at the same RPM. Engines are just like us, the more load = more stress = more work, the quicker to tired.

The same idea can be applied to racing engines. I've watched many races on TV. On every race as far as I can remember, racers DO free revving before the start. If free revving was such NO-NOs, why would any racing engineers allow drivers and riders to do that? Racing engines are extremely fragile because of so much HP is extracted out of specified displacement. I would say engineers will be very sensitive to free revving as much as would be for over speeding (RPM) of engine.

On lawn mower 4 stroke race engines, there maybe excess wear caused by rapid change in RPM, simply due to coincidental lube, no oil pump. There could be lack of lubrication momentarily.

Or, it could be due to its length of connecting rod and throw of crankshaft that causing excess wear on piston and cylinder wall. I think there's a term for it.

In the end, I don't think anyone is endorsing and encouraging free revving. The question was that does it harm engine. I said no as well as few others on this thread. However, I would say revving engine needlessly will accelerate engine wear, simply that engine would have to through that much more cycles compared to a engine running at idle speed.

Whether you agree or not agree with this, it doesn't change anything to me. The same kinds of talks must be taking place in some place else right at this moment. So, I will stop spending my time on this subject.

[wlfpck]

First off, I did not mean to start a huge debate. I simply thought there was a simple agreed upon answer.

Second, I know about valve float however, I thought valve float only occurred at an RPM that exceeds the normal operating limits (Past redline).

A lot of the discussion is around the engine, however, is there any wear and tear to the transmission? Someone earlier said there shouldn't be. I believe that it is because the transmission is disengaged?


Now carrying the discussion on more... but how does this work with DCTs? The engine would be the same as with a TC auto, but would the transmission get damaged?


Just trying to learn more from a mechanical standpoint.