318ti.org forum

Go Back   318ti.org forum > Technical, Maintenance and Modifications > Knowledge Base

Notices

Knowledge Base How to articles and things explained.

.
» Recent Threads
Brake Pad Warning Light
Yesterday 12:13 AM
Last post by zoner
Today 05:10 AM
9 Comments, 220 Views
318ti DASC vs NA 318ti...
11-19-2015 06:24 AM
Last post by Trusted-1
Today 01:45 AM
15 Comments, 1,374 Views
Authentic or Replica m3...
Yesterday 08:23 PM
Last post by Disast3r_Ti
Today 01:04 AM
2 Comments, 95 Views
318Ti M3?
Today 12:09 AM
Last post by eurohb
Today 12:09 AM
0 Comments, 77 Views
WTB OEM Roof Rack
Yesterday 09:35 PM
Last post by Ron k
Yesterday 11:44 PM
2 Comments, 81 Views
What did you do to your...
01-02-2015 01:12 AM
Last post by Disast3r_Ti
Yesterday 09:03 PM
195 Comments, 43,940 Views
Rare NLA 318ti parts
01-20-2016 08:21 PM
Last post by Fast Eddie
Yesterday 06:02 PM
12 Comments, 864 Views
No heat after coolant...
Yesterday 04:08 AM
Last post by eurohb
Yesterday 05:10 PM
2 Comments, 160 Views
m44 Oil Pan
02-03-2016 07:07 PM
Last post by eurohb
Yesterday 05:09 PM
2 Comments, 192 Views
Midnight Tuning...
02-08-2012 06:38 PM
Last post by benz-tech
Yesterday 06:20 AM
153 Comments, 38,579 Views
Comment Share/Bookmark
 
Tutorial Tools Display Modes
Fun with math: determine engine displacement
Fun with math: determine engine displacement
Published by J!m
02-09-2006
Default Fun with math: determine engine displacement

Determine displacement (D) of your engine…

Formula:
D=π/4 (B)2 x S x N

Where D= displacement
B=bore
S=stroke
N=number of cylinders

Example: six cylinder engine with a 3.5 inch bore and a 3.75 inch stroke.

D = π/4 (3.5)2 x 3.75 x 6 = 216.4753688 Cubic Inches (or just 216.5 rounded)

That's great for inches, but what about liters?

For metric units (liters) we must convert measurements to mm (or record them directly in mm), then convert cubic mm to cubic centimeters (if you want to know the CC's of the engine) then finally to liters if you want to know that.

There are exactly 25.400 mm in each inch. If you remember that, the rest is easy…

There are 1000 cubic millimeters in a cubic centimeter

There are 1000 cubic centimeters in a liter.

Therefore (using the same engine above, converting inches to mm):

D = π/4 (88.9)2 x 95.25 x 6 = 3547395.723 cubic millimeters
/ 1000 = 3547.395723 cubic centimeters
/ 1000 = 3.547395723 liters, or rounded, this is a 3.5 liter engine.

The above equation is fun if you have already or plan to over-bore your 'metric' engine. Even if you over-bore in inches (typically 0.010", 0.020", 0.030", 0.040" or 0.060" at most US engine shops) you can convert these numbers easily to mm, and plug them into your equation where the base numbers (numbers in engine manual or blueprint) are in mm. Simply multiply any inch measurements buy 25.4 to get mm.

Example, for a 0.020" over-bore, we simply add 0.508mm to our bore size (in the example above, that's 88.9mm) to get a revised bore size (89.408mm in the example) and a new displacement of 3588.053221cc or (rounded) 3.6 liters.

Wasn't that easy?
Tutorial Tools

  #1  
By demonicdelsol on 06-24-2011, 11:10 PM
Default sir

you can also do it this way....
(pi)3.14159265x bore radius squared x number of cylinders. also on metric (mm) you have to convert to cm when you do it this way. so if your bore stroke is 86x86 on a honda k20, it would be

pi(4.3squared x 8.6) x 4 = 1998.2.... 1liter = 1000cc, honda rounds up. 2.0L
Reply With Quote
Comment

Bookmarks


Currently Active Users Viewing This Tutorial: 1 (0 members and 1 guests)
 
Tutorial Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On

Forum Jump


All times are GMT +1. The time now is 10:01 AM.


.
Powered by site supporters
vBulletin Version 3.8.8
Copyright ©2000 - 2016, Jelsoft Enterprises Ltd.
Copyright ©1999 - 2016, 318ti.org

Tutorial powered by GARS 2.1.8m ©2005-2006
© vBadvanced CMPS v3.2.2
[page compression: 62.24 k/73.93 k (15.81%)]

318ti.org does not warrant or assume any legal liability or responsibility for the accuracy, completeness, or usefulness of any information or products discussed.