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steelcomp was here
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Discussion Starter #1
Remember this thread?:D
Since the thread on bore/stroke combinations is moving in this direction, I thought I'd throw this one out there again.
What makes an engine accelerate? How could an engine with less HP out accelerate an engine with more HP? Or could it?
 

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steelcomp was here
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Discussion Starter #3
Is this based on if all things are equal? Two engines one boat?
What makes an engine accelerate....if one engine out accelerates another engine, something's not equal.
I'm asking about the acceleration rate of an engine...nothing else. At the crank...
 

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Boat Nut
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Assuming these are the same displacement motors?? If so, a short rod will accelerate the crankshaft faster than a longer rod combo.
 

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Cantard
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Rotating mass is a big one.

The list is endless.....we can get right down to ring spacers, valve styles or even clearances.

You can build two engines with the same parts and still make one accelerate quicker than the other.
 

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Not sure if your kidding or not. HP is a measure of work. Acceleration is a measure of how fast the velocity is changing. 2 completely different scalers. Lighter components/less drag are the 2 major reasons that come to mind as to why one engine would accelerate faster than another. Maybe I'm missing something... usually am.
 

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Cantard
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Assuming these are the same displacement motors?? If so, a short rod will accelerate the crankshaft faster than a longer rod combo.
Sure, but rod length will also play a factor in where the quicker acceleration rate can takes place.
 

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steelcomp was here
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Discussion Starter #9
Not sure if your kidding or not. HP is a measure of work. Acceleration is a measure of how fast the velocity is changing. 2 completely different scalers. Lighter components/less drag are the 2 major reasons that come to mind as to why one engine would accelerate faster than another. Maybe I'm missing something... usually am.
Not kidding. HP is just a reference, really of little importance here...I believe lighter components and less friction are important in allowing an engine to accelerate, but I'm wondering what makes it accelerate?
 

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Resident Ford Nut
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Not sure if your kidding or not. HP is a measure of work. Acceleration is a measure of how fast the velocity is changing. 2 completely different scalers. Lighter components/less drag are the 2 major reasons that come to mind as to why one engine would accelerate faster than another. Maybe I'm missing something... usually am.
Those, but also combustion chamber efficiency, less friction drag on the rings.

I'm starting to get the feeling this is a trick question....?:

What makes an engine accelerate ? 1. open the throttle 2. Air/fuel enter the intake track 3. etc.......

But, the expansion of hot gasses in the combustion chamber creates pressure that drives the piston down. The reaction between the oxygen and the fuel burning heats the nitrogen and when the nitrogen expands it pushes on the piston to accelerate the engine. The more air/ fuel you can cram into the chamber ( compression ratio) the more bang you will get out of the reaction. Not much unlike a hot 44 Mag bullet reload with more powder in it vs a factory load with a light load of gun powder in it. Or something like that :)bulb

Sleeper CP :D
 

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steelcomp was here
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Discussion Starter #12
Not a trick question. Just one of those things that make me go "Hmmmm".
So that's one cycle of the process. What makes the next one, and the next one, and the next one....faster and faster (or not), and so on.
Those, but also combustion chamber efficiency, less friction drag on the rings.

I'm starting to get the feeling this is a trick question....?:

What makes an engine accelerate ? 1. open the throttle 2. Air/fuel enter the intake track 3. etc.......

But, the expansion of hot gasses in the combustion chamber creates pressure that drives the piston down. The reaction between the oxygen and the fuel burning heats the nitrogen and when the nitrogen expands it pushes on the piston to accelerate the engine. The more air/ fuel you can cram into the chamber ( compression ratio) the more bang you will get out of the reaction. Not much unlike a hot 44 Mag bullet reload with more powder in it vs a factory load with a light load of gun powder in it. Or something like that :)bulb

Sleeper CP :D
 

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Boat Nut
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Air, fuel, compression to atomize the fuel/air, and spark to ignite for combustion. Acceleration is controlled or limited by the air fuel mixture it is fed. Simple question simple answer:)devil But the question is really what makes it happen faster, and how.
 

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Not kidding. HP is just a reference, really of little importance here...I believe lighter components and less friction are important in allowing an engine to accelerate, but I'm wondering what makes it accelerate?
The addition of air(as caused by the pushing of accelerator peddle ) Which is matched by the addition of feul (don't care if it is diesel gasoline or keorosine) The human body when it works hard breathes hard. Food adds the abbility to continue working by protien and fats and all the other things we stuff down our throats. An engine will build rpm by the addition of air and feul. To make it build rpm and power will easily be related to the amount of feul you can burn with out getting FAT and how fast you can get it and how fast you can get it to produce!! THus as all have stated previous " make it light,make eat at the right time and most of all LET THE MOTOR BREATHE!!!!!!!!!!!!! Now if this is a trick question then my answer would be just thro money at it!
 

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Amatuer
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Acceleration is the result of unequal forces. If the force applied to the crankshaft in the clockwise direction is greater that the force applied in the counterclockwise direction, then the crankshaft will increase its rotational velocity in the clockwise direction.

Is that how basic you wanted to go?

How could an engine with less HP out accelerate an engine with more HP? Or could it?
a = f/m

So a very massive engine could still accelerate slower than one with less hp. Consider an engine with an enormous lead flywheel.
 

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Did you know you can rev a nitrous engine without touching the throttle.:)bulb
Sure! Let the motor idle and hit the button. The system will provide enough feul and inert gas to raise the idle. But for how long before it stumbles and dies. Clue me on this cause i'm not a nos guy. I know what it does and how it works. but not a fan. M
 

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Cantard
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Sure! Let the motor idle and hit the button. The system will provide enough feul and inert gas to raise the idle. But for how long before it stumbles and dies. Clue me on this cause i'm not a nos guy. I know what it does and how it works. but not a fan. M
It,s more the oxygen content than the air flow, if you were to put a 50hp shot of nos on a bbc it would rev to about 5500rpm.

Just a little late saturday night in the garage with the boys after the fridge is starting to look empty info. lol
 

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Not a trick question. Just one of those things that make me go "Hmmmm".
So that's one cycle of the process. What makes the next one, and the next one, and the next one....faster and faster (or not), and so on.

Got it now. I'll think about it on the way home.

Sleeper CP :D
 

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Resident Ford Nut
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What makes the next one, and the next one, and the next one....faster and faster (or not), and so on.
That's a damn interesting question.......:)bulb Have you figuired it out ?

Why doesn't it just rev to 5,800 and stay there :)bulb You got me so far.

Sleeper CP :D
 
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