Reading the DME ( informative post ) - Page 6 - 6SpeedOnline

#76

02-18-2019 | 09:46 PM

SkagitDoug

Registered User

Joined: Oct 2017

Posts: 3

Rep Power: 0

SkagitDoug is infamous around these parts

Quote:

Originally Posted by quick

2)- Ignitions :

There are 3 ignitions in 1 revolution and there are 120 revolutions in a second. That means there are 360 ignitions per second.

Those 360 ignitions cited above are PER REVOLUTION of the crankshaft, not PER SECOND!
So, at 7,000 RPM, there are going to be 2,520,000 ignitions per minute!

#77

02-19-2019 | 06:22 AM

jhbrennan

Registered User

Joined: Apr 2006

Posts: 5,259

From: Austin

Rep Power: 768

Quote:

Originally Posted by SkagitDoug

Those 360 ignitions cited above are PER REVOLUTION of the crankshaft, not PER SECOND!
So, at 7,000 RPM, there are going to be 2,520,000 ignitions per minute!

Sure about that math? If there are 3 ignitions for every revolution, there would be 21,000 ignitions in a minute at 7000 rpm.

#78

02-19-2019 | 09:29 AM

SkagitDoug

Registered User

Joined: Oct 2017

Posts: 3

Rep Power: 0

Math (and mind) on Vacation

Quote:

Originally Posted by jhbrennan

Sure about that math? If there are 3 ignitions for every revolution, there would be 21,000 ignitions in a minute at 7000 rpm.

Gosh, I wish I could remember what I as thinking, as I'm sure you do, but 2,520,000 is 7,000 * 60 * 60!

Last edited by SkagitDoug; 02-19-2019 at 09:32 AM.

#79

02-19-2019 | 09:45 AM

jhbrennan

Registered User

Joined: Apr 2006

Posts: 5,259

From: Austin

Rep Power: 768

Quote:

Originally Posted by SkagitDoug

Gosh, I wish I could remember what I as thinking, as I'm sure you do, but 2,520,000 is 7,000 * 60 * 60!

Go on vacation...or get a better calculator - 7,000 x 60 x 60 = 25,200,000. I think what you meant was 21,000 ignitions/minute x 60 minutes = 1,260,000.

#80

02-19-2019 | 09:52 AM

SkagitDoug

Registered User

Joined: Oct 2017

Posts: 3

Rep Power: 0

Quote:

Originally Posted by jhbrennan

Go on vacation...or get a better calculator - 7,000 x 60 x 60 = 25,200,000. I think what you meant was 21,000 ignitions/minute x 60 minutes = 1,260,000.

My 60*60 was sec/min * min/hr, which is meaningless. But, there was no time period in the original post, so the math in it was, likewise, meaningless.