Word Problem
Sold my sol for Silvia
Thread Starter
Join Date: Sep 2007
Posts: 211
Likes: 0
Received 0 Likes
on
0 Posts
Word Problem
I have a stock bottom end, redtop SR20DET with a stock compression ratio of 8.5:1. I replaced the head gasket with a 1.1mm Cosworth head gasket. What is my new compression ratio? Show your work.
Seriously I want to know the math for figuring this sort of thing out.
Seriously I want to know the math for figuring this sort of thing out.
__________________
ΔxΔp ≥ h
Join Date: Mar 2006
Posts: 1,909
Likes: 0
Received 0 Likes
on
0 Posts
I fail to see how this is a word problem.
This is a word problem
"John is twenty years younger than Amy, and in five years' time he will be half her age. What is John's age now?"
Engine Compression Ratio (CR) Calculator
Right thurr...
This is a word problem
"John is twenty years younger than Amy, and in five years' time he will be half her age. What is John's age now?"
Engine Compression Ratio (CR) Calculator
Right thurr...
__________________
Offset-----Less is MORE!!
Join Date: Jan 2004
Posts: 7,160
Likes: 0
Received 0 Likes
on
0 Posts
15!
__________________
Looking to buy or sell Real Estate, give me a call.
http://liberty-vip.com Flush ≠ VIP. Spread the word in 2012
Looking to buy or sell Real Estate, give me a call.
http://liberty-vip.com Flush ≠ VIP. Spread the word in 2012
Registered User
Join Date: Jan 2006
Posts: 14,143
Likes: 0
Received 0 Likes
on
0 Posts
...i thought you meant you had a problem with Microsoft Word
__________________
Wanna see picsfrom carevents in Japan?
http://www.hashiriya.net
R.I.P - Tim Aldrich (Osama Tim Laden)
http://www.hashiriya.net
R.I.P - Tim Aldrich (Osama Tim Laden)
Offset-----Less is MORE!!
Join Date: Jan 2004
Posts: 7,160
Likes: 0
Received 0 Likes
on
0 Posts
what do I get for answering ph34r??
__________________
Looking to buy or sell Real Estate, give me a call.
http://liberty-vip.com Flush ≠ VIP. Spread the word in 2012
Looking to buy or sell Real Estate, give me a call.
http://liberty-vip.com Flush ≠ VIP. Spread the word in 2012
Retired
Join Date: Jan 2003
Posts: 5,095
Likes: 0
Received 0 Likes
on
0 Posts
The equation has a few easy steps.
(Combustion chamber volume)+(gasket volume)+(TDC piston volume)+(piston dish volume)
Number is the volume when the piston is at the top. To find the volume when the piston is at the bottom, take all that and add the cylinder volume. To get the compression ratio, it's just big number over small number.
Tips:
The comb chamber volume is going to be in cc's, so stay in that unit of measure. That is, cc = cubic centimeters = cm x cm x cm. Convert all mm measurements to cm!!!
Gasket volume is pi*r^2 times gasket thickness. Ex: 3.1415*(4.35^2)*0.11 Where a gasket diameter of 87mm -> 8.7cm -> 4.35cm radius. 0.11 is the 1.1mm thickness in cm.
TDC piston volume: when the piston is at TDC, it may be below or above the surface of the block. This either leave adds or subtracts volume. On the SR, it's 0.05mm below, so you're adding a little volume. You calculate this volume the same way as the gasket volume. Or, just add it to the gasket volume calculation to save time. Here we'd use 0.115 in the above calc, which is that extra 0.05 tacked on. The radius is 86mm instead of 87mm, but the overal imact of inserting this into the gasket calc is negligible.
Piston dish is 15cc. Head volume is 45cc.
Cylinder volume is 86mm x86mm -> 3.1415*(4.3^2)*4.3, which should give you 499.5cc's.
