what is the formula to find the area of a circle with a 55 mm diameter????

FED 387 · 07-20-2008, 11:17 PM

OK all you math guys what is it or how do you convert inches to MM--Comp 387

Alan Roehrich · 07-20-2008, 11:36 PM

An inch is 25.4 MM. A millimeter is 0.03937007874".

FED 387 · 07-20-2008, 11:41 PM

Thank you--comp 387

Adger Smith · 07-20-2008, 11:52 PM

Dick,
This is very handy for formulas. I keep it around to help cover my A** when I'm brain dead. Which happens alot!!
http://www.csgnetwork.com/automotiveconverters.html

FED 387 · 07-20-2008, 11:59 PM

Thanx Adger great site---Actually was trying to figure the most aerodynamic hood scoop and the necessary opening to handle some carbs-----Thanx Comp 387

Adger Smith · 07-21-2008, 01:39 AM

According to: Bob Szabo article

One method for ball-parking the size of a hood scoop is to look at the column of air that the hood scoop takes in from the speed of the vehicle. That amount is a function of the engine air demand, the velocity of the vehicle, and the inlet scoop area. The equation for that relationship is:

vehicle velocity = engine air demand / scoop area

Try this:
vehicle MPH = (engine cfm / scoop area in square inches) x (60 x 1/5280) / (1/144)

where:

60 = minutes (m) per hour (H)
1/5280 = miles (M) per foot (f)
1/144 = square feet per square inch
(60 x 1/5280) / (1/144) = 1.64
vehicle MPH = engine CFM x 1.64 / scoop area (square inches)

07-20-2008, 11:17 PM	#1
FED 387 VIP Member Join Date: Jun 2006 Posts: 3,417 Likes: 522 Liked 331 Times in 179 Posts	what is the formula to find the area of a circle with a 55 mm diameter???? OK all you math guys what is it or how do you convert inches to MM--Comp 387

07-20-2008, 11:36 PM	#2
Alan Roehrich Veteran Member Join Date: May 2006 Location: Murfreesboro TN Posts: 5,105 Likes: 1,564 Liked 1,789 Times in 408 Posts	Re: what is the formula to find the area of a circle with a 55 mm diameter???? An inch is 25.4 MM. A millimeter is 0.03937007874". __________________ Alan Roehrich 212A G/S

07-20-2008, 11:41 PM	#3
FED 387 VIP Member Join Date: Jun 2006 Posts: 3,417 Likes: 522 Liked 331 Times in 179 Posts	Re: what is the formula to find the area of a circle with a 55 mm diameter???? Thank you--comp 387

07-20-2008, 11:52 PM	#4
Adger Smith VIP Member Join Date: Dec 2001 Location: Texarkana Ark/TX Posts: 2,446 Likes: 575 Liked 880 Times in 311 Posts	Re: what is the formula to find the area of a circle with a 55 mm diameter???? Dick, This is very handy for formulas. I keep it around to help cover my A** when I'm brain dead. Which happens alot!! http://www.csgnetwork.com/automotiveconverters.html __________________ Adger Smith (Former SS) Last edited by Adger Smith; 07-20-2008 at 11:53 PM. Reason: sp

07-20-2008, 11:59 PM	#5
FED 387 VIP Member Join Date: Jun 2006 Posts: 3,417 Likes: 522 Liked 331 Times in 179 Posts	Re: what is the formula to find the area of a circle with a 55 mm diameter???? Thanx Adger great site---Actually was trying to figure the most aerodynamic hood scoop and the necessary opening to handle some carbs-----Thanx Comp 387

07-21-2008, 01:39 AM	#6
Adger Smith VIP Member Join Date: Dec 2001 Location: Texarkana Ark/TX Posts: 2,446 Likes: 575 Liked 880 Times in 311 Posts	Re: what is the formula to find the area of a circle with a 55 mm diameter???? According to: Bob Szabo article One method for ball-parking the size of a hood scoop is to look at the column of air that the hood scoop takes in from the speed of the vehicle. That amount is a function of the engine air demand, the velocity of the vehicle, and the inlet scoop area. The equation for that relationship is: vehicle velocity = engine air demand / scoop area Try this: vehicle MPH = (engine cfm / scoop area in square inches) x (60 x 1/5280) / (1/144) where: 60 = minutes (m) per hour (H) 1/5280 = miles (M) per foot (f) 1/144 = square feet per square inch (60 x 1/5280) / (1/144) = 1.64 vehicle MPH = engine CFM x 1.64 / scoop area (square inches) __________________ Adger Smith (Former SS) Last edited by Adger Smith; 07-21-2008 at 01:47 AM. Reason: sp