Utility for Figuring RPMs....

[Ted Borck <tborck@domain.elided>]

On Wed, 4 Feb 1998, ihc-digest wrote:


> Date: Tue, 03 Feb 1998 10:32:46 -0500
> From: tsm1@domain.elided (Tom Mandera)
> Subject: Re: Figuring RPMs....
> 
> >Hi All,
> >
> >Since my '58 A-102 does not have a Tachometer, I thought I could figure
> >But after doing so, the RPMs seem sort of low.  Can you all check my math....
> >MPH/Gear 1 2 3 R
> >60 8067 4400 2736 10069
> 
> Jeff,
> 
> It all looks OK.  I did this calculation for a bunch of possibilities, and
> made a web page.. see http://www.tmcom.com/~tsm1/scout/faq/index.html  and
> look under the Tire Size / Gearing / RPM.
> 
> The equation I used is:
> 
> Tire Diameter / 168 * RPM / Gear Ratio = MPH

<snip>

There is a handy utility found at http://www.camquest.com

	*Download Camquest-cam selection software and utilities*

Among other things it will calculate RPM@speed, Effective Ratio (which 
contains a handy tire diameter calculator), engine displacement, etc.

Its a DOS program which will run within WIN95 in a DOS box (you will 
probably have to put FILES=70 in your config.sys file).  Haven't tried it 
in Windows.X.

Sorry I can't get it to run on my MAC.

But its a fun program if you're sitting around and thinking.....

Let's see... If I put the 3:54's in and run 31 inch tires, what will my 
RPMs be at 70 MPH.  (This part of the program is limited by the fact that 
it assumes that your transmission ratio is 1:1.)

	or

If stroked the 392 1/2 inch (kids don't try this at home) my displacement 
will be.....

	or

What size carburetor do I need if I stroke my 392 1/2 inch.


Ted Borck	tborck@domain.elided