Putting Car in Nuetral and Reving it, can it ruin the engine?

  • Thread starter Thread starter McLaren'sAngel
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Originally posted by VIPERGTSR01
have you ever heard of water injection??, it works well
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:confused:
 
youve never heard of water injection?
 
some old fighter aircraft use it for emergancy power.

also you can buy water injection kits for cars. it sprays a mist of water down the intake which cools intake temps (cool air = dense air = more power) also slighly raises compression
 
Ahhh. Ok, i see now.
 
Originally posted by Mike Rotch
Secondly, from what I remember reading a while back, revving the engine in neutral IS bad. When an engine is revved high on the move i.e. in gear, the pistons and piston heads have the inertia of the engine/transmission to move against.
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Not just the pistons, but the connecting rods and the crankshaft as well.

The notion is that the entire bottom end is designed to operate at high RPM while pushing a load (ie -the entire car). Take away that load (disconnecting the engine and drivetrain by shifting into neutral) and the shearing forces that act on the crankshaft will damage it over time because it has nothing to 'push against'.

I've read this before, but not from any sources I consider truly credible. It may be true, or it may be yet another peice of Internet misinformation that gets spread around by people who don't know anything about cars.

I can point to the fact that the car enters neutral at high RPM everytime you shift after hitting the redline. While WOT shifts at redline is not "good" for the drive train, it is the type of stress every high performance car is engineered to endure.

But there is one part of this theory which does make sense to me. Without a load, the engine can rev more quickly. This is especially true of cars with a lightened aftermarket flywheel or underdriven accessory pullies. The inertial forces that act on the pistons, rods and crank from being accelerated more quickly through their movements (ie go from moving slowly to moving very quickly in the shorter amount of time) can lead to undue mechanical stress that will ultimately shorten the life of all the components. That does make sense to me.


Originally posted by Mike Rotch
With the car stationary, the only force keeping the piston-head from flying into the cylinder head is the piston. It is extra stress on the components that, for the most part, is unnecessary.
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What are you talking about? :confused: The connecting rod keeps the piston from crashing into the head, and this is true whether the car is in gear and moving or in neutral.


M
 
Originally posted by Mike Rotch
With the car stationary, the only force keeping the piston-head from flying into the cylinder head is the piston. It is extra stress on the components that, for the most part, is unnecessary.

:grumpy: Well what I read was something to that effect anyway.
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I understand this is just something you read, it's also just plain wrong.

At a given steady-state RPM, the stress is the same on the internals. It's not a matter of having something to "push against". In fact, it would be better for the engine to run unloaded at a given RPM than it would be loaded, because less load means less fuel is required to keep the engine turning that speed. Less fuel equals smaller explosion at each firing equals less stress on the internal components of an unloaded engine.

Now, the fact remains that an unloaded engine is easier to overrev because it can change its speed much more quickly than a loaded engine can. However, I would assume that the stress brought about strictly because of the change in acceleration would be less than the stress brought about by the normal reciprocation, and much much less than the stress brought about by accelerating a loaded engine.

It boils down to the simple fact that driving cars harder wears them more than driving them gently. There's nothing magically worse about revving the car in neutral.
 
Racers rev the engine all the time, BUT, they also rebuild them after a couple races. We did ours after 3 races.
 
Been racing since I was 8. I'm now 41.
:cheers:
 
Kinda off-topic but there was a guy in an old talon parked and had his bass up so loud, that when he went to reach in his backseat for somethin, he accidently had his foot on the accelerator and red-lined it for about 10 seconds lol. I'm assuming it was his brother who came up to him and smacked him in the face afterwards.
 
The piston rotates and completes the 4-cycles of your engine. When the piston is not working properly, those cycles will not complete properly and you will ruin your engine. When he was sayin that the piston keeps the piston-head flying into the cylinder, picture someone in your room, on a trampoline, flying right through the ceiling, that's what happens when a piston-head flies through the cylinder. (Did that example make sense?) lol
 
Originally posted by McLaren'sAngel
hiya again :D

So what do you mean by it WILL shorten the life of your Engine
"But as said previously, it WILL shorten the life of your engine, and you DEFINITELY wanna wait till it's at it's constant operating temp."

And also, about how you said about people with Automatics, Reving it in Nuetral and then putting it in D "Drive", do you mean as in more like Rev it and dont put it on D until the transmission rotation STOPS in the engine and then put it on D?
:D
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I mean just what I said. If you are always revving your engine up in neutral or pushing it hard it shortens the engine's lifespan a little. The longetivity decreases as you make the engine work harder. Aside from throwing rods and whatnot, another reason to wait for your engine to reach operating temp before pushing it hard is because that will significantly shorten the life of the engine if done often enough.

When I say don't have the auto tranny in N, rev it up and then put it in D, I mean don't put your car in neutral at a standstill, rev it up to 5000 rpms and while it's revved up put it into drive. Don't do that, it's terrible for the transmission! Although you'd perhaps think it was like a clutch drop on a manual transmission car it isn't. You generally wanna wait until it's back to idle as someone else had said. What hurts your face more, someone putting their fist on it and pushing it or someone straight up punching you in the jaw or nose as hard as he/she/it can? That's literally the kind of difference it makes to the tranny.
 
I dont think its that bad reving your car occasionally because why would manufacturers allow their engines to damage themselves? Its like having a self destruct button. I think past the rev limiter is when your engine risks serious damage regardless of whether its in neutral or not.
 
Slick Rick
. I think past the rev limiter is when your engine risks serious damage regardless of whether its in neutral or not.
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It's a bit worse...
And less bad when reving the 1st, less when reving the 2nd etc.
The problem is the duration of the reving, not how often the engine revs.
If you care about your car and and not reving it more than...6 sec approximately, it's ok.
 
Wow, this one's pretty old. I'll just let it be...
 
Wow... I am glad people point out dates, cause I thought this was maybe a somewhat current thread... not 2 and a half years old.

Still, revving in neutral is generally not the best idea. Just more time your engine spends spinning that it doesn't need to.
 
I dont really think it matters if a thread is old or not. I was doing a search yesterday, found this thread, it was interesting, read it all and then posted my opinion.
 
I remember my first car would not idle unless you held it at ~4500 rpms when it was cold...so I'd have to start it up cold then hold it at that rpm for 2-3 mins while it warmed up, it would typically fill my yard with foul smelling smoke every morning :lol:

That couldn't have been good for it.
 
McLaren'sAngel
hiya! :D

I am not a "technical" smarty yet like all you geniuses :O , I am only a "basic" VERY BASIC type gurly :O I am only familiar with basic stuff like the type of cars that have drives like, FF, RR 4WD etc. V8, V6, Inline-6 and it goes on :O
Anyways... yea I am a basic compared to all you smarties :O :D
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Yeeeah don't worry. I only started taking notice a few years ago... although I sort of learnt without realising through dad, boyfriend, various games... and the fact that I've been going to Combe Castle (track) since I was about 2 months old. :D

But still. It's great. Keep going.
 
McLaren'sAngel
hiya! :D

Well I do know something about cars :D But its a sad thing how I only pretty much learn it from playing Gran Turismo 3 :O The purpose of learning from it is to help me understand and "know" the car a bit. And I also conduct alot of research online about certain cars that are popular such as the Skylines, RUF, Vipers and it goes on and on :D
I am not a "technical" smarty yet like all you geniuses :O , I am only a "basic" VERY BASIC type gurly :O I am only familiar with basic stuff like the type of cars that have drives like, FF, RR 4WD etc. V8, V6, Inline-6 and it goes on :O
Anyways... yea I am a basic compared to all you smarties :O :D
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Don't expect to learn much about engines and drive trains from playing GranTurismo. While you might learn a little about how a car handles from these video games, you don't learn anything about the actual mechanics. If you really wanna learn the basics, go to www.howstuffworks.com and start reading about all the major components of a car.
 
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