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Discussion Starter #1
So, I have read on here in a few places that reving an SI engine past 5K with no load on it (i.e. clutch in, car at a dead stop) is bad for the motor. Is this the same if the car is moving?? (i.e. in gear / clutch out, car coasting to a stop, foot not on the gas).
 

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Discussion Starter #4
U would need to be in a lower gear than the one ur in to slow down stronger and faster tho...
Thanks... Not worried about stopping or slowing down though, I am wondering if -->

5500 RPM in Neutral with foot on the gas is the same 5500 RPM in gear with foot not on the gas in respect to being detrimental to the engine...
 

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Not the same. In neutral the engine is not under load and the ecu keeps the engine from revving any higher to avoid damage...don't do this lol
 

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Discussion Starter #6
True, but isn't it not under load when you you have your foot off the gas and the rear wheels are driving the motor?
 

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5500 RPM while in neutral?! Are you trying to rocket off to the moon when your launching?

For no reason what so ever should you be in neutral at 5500 rpm.
 

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True, but isn't it not under load when you you have your foot off the gas and the rear wheels are driving the motor?
:facepalm:

So, I have read on here in a few places that reving an SI engine past 5K with no load on it (i.e. clutch in, car at a dead stop) is bad for the motor. Is this the same if the car is moving?? (i.e. in gear / clutch out, car coasting to a stop, foot not on the gas).
constantly revving the car while in neutral, with no load on the engine is not good.
its not gonna do any serious damamge, but why would you do this anyway?

the few times the car is revved up to launch will not make a big differance in reliability (except for the axels and other drivetrain parts that are strained fromt eh launch)
 

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Discussion Starter #14
:facepalm:
constantly revving the car while in neutral, with no load on the engine is not good.
its not gonna do any serious damamge, but why would you do this anyway?

the few times the car is revved up to launch will not make a big differance in reliability (except for the axels and other drivetrain parts that are strained fromt eh launch)
Come on guys, I welcome all comments, but please read the question that is being asked before replying... :facepalm:

To clarify..

I AM NOT TALKING ABOUT, OR IN THE PROCESS OF DOING, ANY OF THE FOLLOWING ACTIVITIES...
Engine Braking
Setting in Neutral Revving the engine
Trying to launch
Rocketing to the Moon
Trying to slow down faster by going to a lower gear...

I will try this one more time before asking over at K20a.org

Is 5500 RPM in Neutral with foot on the gas the same as 5500 RPM IN GEAR with foot OFF the gas?? Specifically in regards to ENGINE STRESS...

Here are the three things I am trying to confirm or deny to be true, nothing else...

#1 - Foot on gas, engine driving rear wheels --> Positive Load on Engine (Not detrimental to the engine past 5500 RPM)

#2 - Foot on gas, Neutral -> No Load on Engine (Detrimental)

#3 - Foot OFF gas, in gear -> Negative Load on Engine (Is this equivalent in stress to a engine no load at 5500 RPM???)
 

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Come on guys, I welcome all comments, but please read the question that is being asked before replying... :facepalm:

To clarify..

I AM NOT TALKING ABOUT, OR IN THE PROCESS OF DOING, ANY OF THE FOLLOWING ACTIVITIES...
Engine Braking
Setting in Neutral Revving the engine
Trying to launch
Rocketing to the Moon
Trying to slow down faster by going to a lower gear...

I will try this one more time before asking over at K20a.org

Is 5500 RPM in Neutral with foot on the gas the same as 5500 RPM IN GEAR with foot OFF the gas?? Specifically in regards to ENGINE STRESS...

Here are the three things I am trying to confirm or deny to be true, nothing else...

#1 - Foot on gas, engine driving rear wheels --> Positive Load on Engine (Not detrimental to the engine past 5500 RPM)

#2 - Foot on gas, Neutral -> No Load on Engine (Detrimental)

#3 - Foot OFF gas, in gear -> Negative Load on Engine (Is this equivalent in stress to a engine no load at 5500 RPM???)
First of all, if you can't figure out that a Civic is a FWD vehicle, you're an idiot.

Secondly, #3 IS engine braking. Any time you take your foot off the gas while in gear, the engine will begin to slow down, and hence, engine-brake.

Lastly, Revving the engine to 5500k while not in gear is exactly the same as revving to 5500k while in neutral and stopped (or, "trying to launch", as you would say). The only difference is you are rolling. Yes, it is bad for the engine. And no, engine braking is not bad for the engine.
 

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You have a rear wheel drive conversion Civic?

#1 - That would be accelerating... Stress of pulling the car.
#2 - Uhhh.... why? Stress of overworking the motor.
#3 - That would be engine braking... Stress of pushing back a heavy car.
 

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Discussion Starter #18
You have a rear wheel drive conversion Civic?

#1 - That would be accelerating... Stress of pulling the car.
#2 - Uhhh.... why? Stress of overworking the motor.
#3 - That would be engine braking... Stress of pushing back a heavy car.
Haaaa!!! I did say rear wheels didn't I?? :pat: That's what I get for trying to post late at night...

Well, regardless, this thread has gone to crap.... Even after a couple of attempts to reiterate the question, everyone replying has been unabble to grasp that I am asking a question about engine dynamics with regards to stress on the bearings, pistons, connecting rods etc. Specifically in regards to positive and negative loads, engine harmonics, etc...

I KNOW WHAT LAUNCHING IS AND AM NOT ASKING HOW TO LAUNCH.
I KNOW WHAT ENGINE BREAKING IS AN AM NOT TRYING TO ASK HOW TO ENGINE BREAK!
I KNOW HOW REVVING THE ENGINE IN NEUTRAL IS BAD AND AM NOT ASKING ABOUT THAT.. :deadhorse:

The only thing I have written so far that any one seems to have read was the accidentally typing the work "rear"

Here's the white flag.... I give up, and will make no more replies to this thread. There are better places to ask technical questions of this sort without all of the drama. :surrender:
 

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The theory is (I've not personally confirmed or refuted that it happens, so I figure better safe than sorry) is that when free revved with no load, parts can "chatter", or basically rattle within the constraints of their tolerances, and this could cause increased engine wear if it causes any metal on metal contact which wouldn't have happened otherwise.

When in gear (5500 RPM or any other) with your foot off the gas, the motor is still connected directly to the transmission and drive line. The motor is being pushed by the wheels, rather than the wheels being pushed by the motor. It's a different kind of load. While it isn't technically engine load (when talking about the work the engine is doing) there is still physical load on the parts, preventing the feared chattering.

I've seen the chattering people are worried about on bearing in electric motors, and other situation, so the theory is sound. However, whether or not the same phenomenon occurs in an engine, I cannot say.
 

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this is a dumbass question.

Rev your car in neutral all you want when it's warmed up. It will still live over 100k miles.

guarantee it.
 
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