i've always wondered...

[Andylad13]

how many crank revolutions do we get when our engines fire all 8?

i was just doing the math, and when im crusing at 2,000 rpms, my crank is spinning 33.3 times per second. thats crazy to think things can stay put and are balanced so well that they dont blow apart. so then i was thinking how fast the pistons fire and then i came up with the question... either way, my mind is still convinced that these engines, and all engines are absolutely amazing.

 

[6.9poweredscout]

imagine a 4 cyl honda turning 10K rpm, how about a motorcycle turning 15K rpm? i remember the nitromethane powered r/c truck i had turned like 25K rpm. pretty neat eh?

-Jon

 

[Russ]

and then think that the pistons are stopping and starting twice that amount

 

[FordGuy100]

how many crank revolutions do we get when our engines fire all 8?

i was just doing the math, and when im crusing at 2,000 rpms, my crank is spinning 33.3 times per second. thats crazy to think things can stay put and are balanced so well that they dont blow apart. so then i was thinking how fast the pistons fire and then i came up with the question... either way, my mind is still convinced that these engines, and all engines are absolutely amazing.

Or think of a turbo, 100K+ rpm's .

My truck used to start within one or two revolutions. Its now up in the 4-8 depending on the temp outside/engine temp.

 

[oldmisterbill]

and that the 4 cyl Honda at 10,000 RPM is sparking 333 times a second !!

 

[MUDKICKR]

1 have a 2007 yamaha R1, i love that thing. to hear it at about redline is just music to my ears, but a few weeks ago i was doing a wheelie and around 80 mph my chain broke in half. now its got a nice hole in the block, but oh well its at the stealership getting an estimate on it for repair. i also have a 2005 R6 race bike, now that thing revs up fast. it is kinda fuuny to think about how much and how fast things are going in a motor "engine". even a engine that is so close to you without a firewall.

 

[MIDNIGHT RIDER]

1 have a 2007 yamaha R1, i was doing a wheelie and around 80 mph my chain broke in half. now its got a nice hole in the block,

It's a wonder it didn't make a hole in your head.

 

[Agnem]

Now your beginning to understand why RPM's hurt fuel milage. The more R's you turn, the more injection events per second, and the more fuel your blowing through unnecessarily.

 

[MUDKICKR]

it didnt try to go for my head, just my nice leo vince exhaust, chain guard, engine, rear shock res. and swingarm.

 

[Andylad13]

your comments are fun to read, but no one has answered my question yet.

 

[tractorman86]

they are "4" strokes so each piston is up 2 times per cycle; starting from top(1down{intake}) (2up{compression}) (3down{fire}) (4up{exhaust})

 

[Flagship]

how many crank revolutions do we get when our engines fire all 8?

2.

Being a 4 stroke engine, it takes two revolutions to complete 4 strokes, or one cycle. Your crank is moving all the pistons at the same time but each piston is at a different position in the cylinder in respect to the others. Although each cylinder fires only every other revolution, all cylinders will fire within two revolutions.

When your engine is turning 2000 RPM, your 8 cylinder engine is firing 4000 cylinders per minute! Put it another way, your injector pump is providing over 66 pulses every second. You're moving 60.8 liters of air per second.... you can play with the math! The figures are fun.

Flagship

 

[DeepRoots]

more math for you.
the generator on our boat has 30,500 hours since last overhaul.
new injectors and head gaskets is all its gotten, burns 1 quart of oil every 24 hours.
being a two stroke 4-71 detroit, thats alotta firings in that time running 1200rpms

 

[riotwarrior]

they are "4" strokes so each piston is up 2 times per cycle; starting from top(1down{intake}) (2up{compression}) (3down{fire}) (4up{exhaust})

OK the for strokes of a 4 stroke engine...are as follows

Suck



Sqeeze



Bang



Blow

any other description is unacceptable

 

[tractorman86]

OK the for strokes of a 4 stroke engine...are as follows

Suck



Sqeeze



Bang



Blow

any other description is unacceptable

well since you put it that way, i retract my previous statement