2 hours ago, taninthai said:

What’s the cbr650 Rev to then ,it’s a replacement for Honda hornet and my hornet screams to 16,000rpm

 

????

56 minutes ago, papa al said:

papa's 1st bike in 1967 was a 100cc

twin.

If I could only have one bike. 

13 hours ago, taninthai said:

What’s the cbr650 Rev to then ,it’s a replacement for Honda hornet and my hornet screams to 16,000rpm

Only the Honda Hornet 250 would rev to 16K. The 250,s from Yamaha , Kawasaki , Suzuki would rev up to 20K. The Hornet 400 is 14K,and the 600 is 12K

28 minutes ago, ktm jeff said:

Only the Honda Hornet 250 would rev to 16K. The 250,s from Yamaha , Kawasaki , Suzuki would rev up to 20K. The Hornet 400 is 14K,and the 600 is 12K

Yep my mistake that pic must be 250cc clocks the 600cc revs up to 13,000 rpm????

 

ONLY  ???? 13K. Thats still over  216 times PER SECOND.  Up , stop . Down , stop.  Round and round. Valves twitching open/close. A miracle these engines. 

23 hours ago, ktm jeff said:

ONLY  ???? 13K. Thats still over  216 times PER SECOND. Up , stop . Down , stop.

 

How many times does each cylinder go up, stop, down, stop, on a 4 stroke inline 4 engine at 13k rpm?

 

 

 

16 minutes ago, Happy Grumpy said:

 

How many times does each cylinder go up, stop, down, stop, on a 4 stroke inline 4 engine at 13k rpm?

Same as for a single.

Depends on how long you run it.

What! ; trick question.

Cylinders don't go up & down. !!

Ha ha .

Good one.

Someone seems to think they do it 216 times a second. 

33 minutes ago, Happy Grumpy said:

Someone seems to think they do it 216 times a second. 

Assuming you ment piston and not cylinder then I'd also say a bit over 216 times per second.

 

Doesn't matter how many cylinders or 2 stroke vs 4 stroke. A RPM is one round on the crankshaft which is one instance of "go up, stop, down, stop" for a given cylinder assuming it was all the way down at the start. Therefor at 13k rounds per minute you have 13000/60 rounds per second. Each cylinder does the exact same amount of RPM.

 

What are you thinking then?

2 hours ago, Happy Grumpy said:

How many times does each cylinder go up, stop, down, stop, on a 4 stroke inline 4 engine at 13k rpm?

 

38 minutes ago, eisfeld said:

Doesn't matter how many cylinders or 2 stroke vs 4 stroke. A RPM is one round on the crankshaft which is one instance of "go up, stop, down, stop" for a given cylinder assuming it was all the way down at the start. Therefor at 13k rounds per minute you have 13000/60 rounds per second. Each cylinder does the exact same amount of RPM.

 

What are you thinking then?

 

I'm simply asking the question.

 

A 4 stroke engine, with 4 pistons/cylinders.... and the crank RPM is 13rpm.

 

Each of the 4 pistons are going up/down 13k per minute. So the total number of pistons going up/down on a 4 cyl engine in one minute is 52,000:.. 4 pistons each doing the up/down 13,000 per minute.

 

 That's what you're confirming?  

 

 

Or is it each of the 4 pistons fire once per revolution? 

Each cylinder fires once every two revolutions on a 4-stroke.

 

4 strokes:

suck
stuff
bang
belch

 

 

6 hours ago, Happy Grumpy said:

Or is it each of the 4 pistons fire once per revolution? 

Ha ha.

Another trick question.

Pistons don't fire.

Plugs and fuel do.

 

This guy is good !!

????

 

9 hours ago, Happy Grumpy said:

I'm simply asking the question.

 

A 4 stroke engine, with 4 pistons/cylinders.... and the crank RPM is 13rpm.

 

Each of the 4 pistons are going up/down 13k per minute. So the total number of pistons going up/down on a 4 cyl engine in one minute is 52,000:.. 4 pistons each doing the up/down 13,000 per minute.

 

 That's what you're confirming?  

 

 

Or is it each of the 4 pistons fire once per revolution? 

 

The question keeps changing and seems unclear to me. First it was about ups and downs, then about cylinders, then about how many times the plugs fire?

35 minutes ago, eisfeld said:

Or is it each of the 4 pistons fire once per revolution? 

On some engines the plug does fire every revolution, even on four stroke engines. It even has a name. Wasted spark design. https://en.wikipedia.org/wiki/Wasted_spark

 

Happens of four cylinder bikes when there are only two coils. 

9 hours ago, Damrongsak said:

Each cylinder fires once every two revolutions on a 4-stroke.

So 7,500 times per minute at 13,000 rpm. 

35 minutes ago, Happy Grumpy said:

So 7,500 times per minute at 13,000 rpm. 

Nope ????

 

@VocalNeal I think you misquoted me, that was the Grumpy who said that

1 hour ago, Happy Grumpy said:

So 7,500 times per minute at 13,000 rpm. 

You sir

are truly hilarious.

papa bows to you.

Bravo.

Bravo.

4 hours ago, Happy Grumpy said:

So 7,500 times per minute at 13,000 rpm. 

But with 4 cylinders that are 26,000 sparks per minute. Sounds somehow faster. ???? 

^ lets not forget that the fuel injector(s) operates at the same frequency.????

23 hours ago, Happy Grumpy said:

 

How many times does each cylinder go up, stop, down, stop, on a 4 stroke inline 4 engine at 13k rpm?

 

 

 

If the engine is doing 13K , then per rev , each piston , in each cylinder , goes both up and down per rev. So each piston goes down AND up ( or up AND down ) every rev.

...so 7500 for 4-banger?

3 minutes ago, papa al said:

...so 7500 for 4-banger?

No

Lets keep the question consistent. 4 cylinder. 4 stroke. Spark plug(s) fire on on each cylinders power stroke (per cylinder) only. Everyone happy so far ?.

You need to buy this ASAP....ride like the speed of light...enjoy it....it would look great on you.

Buy two and start chariot racing.

 

 

 

A piston goes both up AND down every rev of the crank. No matter how many pistons the engine has. Single cylinder engine revving at 13000 = piston goes both up and down 13000 times per minute. Spark plug (non wasted type) fires 6500 times per minute per cylinder. Every downward power stroke. The 7500 figure does not relate to 13000 revs. (2x 7500 = 15000). On a 4 cylinder engine the spark plug(S) will be firing 26,000 times per minute (6500 times each).

Now if you want to impress your friends and annoy the neighbors, you need a 500cc Honda NSR500 V4.  At a leisurely 12,000 RPM, it could put out nearly 200 HP.  Of course being a 2-stroke, it fired every revolution, so you get twice as much noise.  Great noise/weight ratio. 

 

 

 

9 hours ago, Damrongsak said:

Buy two and start chariot racing.

 

 

 

Wow! I never saw that one before.

On 3/21/2020 at 9:37 AM, papa al said:

papa's 1st bike in 1967 was a 100cc

Yamaha twin jet? My first bike too...