calculating compression - Hot Rod Forum : Hotrodders Bulletin Board
Hotrodders.com -- Hot Rod Forum



Register FAQ Search Today's Posts Unanswered Posts Auto Escrow Insurance Auto Loans
Hot Rod Forum : Hotrodders Bulletin Board > Tech Help> Hotrodding Basics
User Name
Password
lost password?   |   register now

Reply
 
LinkBack Thread Tools
  #1 (permalink)  
Old 03-21-2012, 11:30 AM
Registered User
 
Join Date: Apr 2010
Location: Temple City
Posts: 53
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
calculating compression

Hi I need help calculating my compression to see if I can run on pump gas. If you could help me figure this out id appreciate it her is all the info
on my motor thanks Joseph


engine is supposed to be about 410 smc

Bore: 30 over Stroke: It is a 6 inch rod

this is the piston specification that i got with the motor they are Racetec pistons. i do have a picture of what the piston looks like if you would like me to email you a pic or somthing.

The actual piston compression is 11 to 1

Engine Information Head type: 40/60 SHIFT Bore diameter: 4.165 in Stroke: 3.750 in Rod length: 6.00 in Displacement/cubic: 408.7 Comp distance 1.125 in Ring Info Ring Number: AT8165 (not sure if this helps) Rail info Rail number: 3.845-168 Wrist Pin Info Pin Type: chamfered Pin number: 927-2700-51-15c Diameter: 0.927 in Length: 2.700 in Piston Information Piston type: dome diameter Diameter 4.1620 in Weight: 456 grams Deck to crown thickness: 0.220 Forging type: A4123F N/C Dome Volume: -.400 cc Gauge point: 0.200 in Ring groove width Top Ring: 0.0640 in 2nd ring: 0.0640 in Oil ring: 02180 in Land width Intake- depth: 0.280 in ,angle: 23.0 degrees Exhaust- depth: 0.280 in ,angle: 23.0 degrees

im not sure wat piston deck height is but i do not piston was flush with the deck if that helps.

gasket thickness im using mls 1144 fel pro -gasket bore: 4.200" -comp volume: 8.9cc -thickness: .040"

i have AFR 210 heads with 75 cc chambers

the drive train is a complete roller The camshaft is a solid roller specs are: lift: .630 Lobe Centers: 106 intake opens at 21 degrees close at 52 degree exhaust opens at 54 degree close at 22 degree

intake is 253 @ .050 0.0200 is 284

exhaust is 256 @.050 0.0200 is 288

    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 03-21-2012, 11:40 AM
SSedan64's Avatar
Registered User
 
Last photo:
Join Date: Dec 2007
Location: Macon, GA.
Age: 50
Posts: 6,016
Wiki Edits: 0

Thanks: 0
Thanked 46 Times in 46 Posts
2 Calculators here >> http://www.kb-silvolite.com/calc.php should help you.
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 03-21-2012, 02:14 PM
Registered User
 
Join Date: Apr 2010
Location: Temple City
Posts: 53
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Quote:
Originally Posted by SSedan64
2 Calculators here >> http://www.kb-silvolite.com/calc.php should help you.
I did it and im getting like 7.86 I don't think that is right but im not sure what I am doin
wrong. Maybe you can get the right ans
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 03-21-2012, 03:25 PM
SSedan64's Avatar
Registered User
 
Last photo:
Join Date: Dec 2007
Location: Macon, GA.
Age: 50
Posts: 6,016
Wiki Edits: 0

Thanks: 0
Thanked 46 Times in 46 Posts
I got:
11.459 Static Cr.
8.980 Dynamic Cr. w/67* Intake Close ABDC & 6" Rod.

Using these Specs:
4.165" Bore X 3.75" Stroke.
.040" X 4.200" Gasket.
-4.00cc Dome Piston.
0" Deck Height, 75cc Chamber.
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 03-21-2012, 03:46 PM
Registered User
 
Join Date: Apr 2010
Location: Temple City
Posts: 53
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
compression

Quote:
Originally Posted by SSedan64
I got:
11.459 Static Cr.
8.980 Dynamic Cr. w/67* Intake Close ABDC & 6" Rod.

Using these Specs:
4.165" Bore X 3.75" Stroke.
.040" X 4.200" Gasket.
-4.00cc Dome Piston.
0" Deck Height, 75cc Chamber.
Hey thanks that sounds better. Which one do I look at so that I know if I can run pump gas.
Reply With Quote Quick reply to this message
  #6 (permalink)  
Old 03-22-2012, 12:39 AM
Registered User
 
Join Date: Apr 2010
Location: Temple City
Posts: 53
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
anyone else think they can help

wondering if anyone else could help me calculate my compression that you go by to decide if you run on pump gas or not?

thanks appreciate it
Reply With Quote Quick reply to this message
  #7 (permalink)  
Old 03-22-2012, 01:57 AM
F-BIRD'88's Avatar
Yada Yada Yada
 
Last photo:
Join Date: Oct 2005
Location: Ontario, Canada
Posts: 9,024
Wiki Edits: 0

Thanks: 3
Thanked 358 Times in 354 Posts
You'd be much better served to build this engine with a real measured cr of 10.5:1 or less for premium pump gas and street use.

11:1 is a little too aggressive. Especially if you have to ask about this stuff.
Reply With Quote Quick reply to this message
  #8 (permalink)  
Old 03-22-2012, 10:10 AM
Registered User
 
Join Date: Apr 2010
Location: Temple City
Posts: 53
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Quote:
Originally Posted by F-BIRD'88
You'd be much better served to build this engine with a real measured cr of 10.5:1 or less for premium pump gas and street use.

11:1 is a little too aggressive. Especially if you have to ask about this stuff.


Well I understand that but this is what I got im just trying to figure out the actual compression you go by to determine what octane I can run on
Reply With Quote Quick reply to this message
  #9 (permalink)  
Old 03-22-2012, 10:41 AM
bigdog7373's Avatar
Of course it's fast
 
Last photo:
Join Date: May 2010
Location: florida
Posts: 2,673
Wiki Edits: 0

Thanks: 13
Thanked 49 Times in 49 Posts
Static......
Reply With Quote Quick reply to this message
  #10 (permalink)  
Old 03-22-2012, 10:43 AM
Registered User
 
Join Date: Apr 2010
Location: Temple City
Posts: 53
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Quote:
Originally Posted by bigdog7373
Static......
.

Yea I guess is that what you go by to determine what octane to go by.
Reply With Quote Quick reply to this message
  #11 (permalink)  
Old 03-22-2012, 10:46 AM
bigdog7373's Avatar
Of course it's fast
 
Last photo:
Join Date: May 2010
Location: florida
Posts: 2,673
Wiki Edits: 0

Thanks: 13
Thanked 49 Times in 49 Posts
You are correct.
Reply With Quote Quick reply to this message
  #12 (permalink)  
Old 03-22-2012, 11:49 AM
Registered User
 
Join Date: Apr 2010
Location: Temple City
Posts: 53
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Quote:
Originally Posted by bigdog7373
You are correct.
Do you think you could tell me what you come up with?
Reply With Quote Quick reply to this message

Recent Hotrodding Basics posts with photos

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Hot Rod Forum : Hotrodders Bulletin Board forums, you must first register.
Please enter your desired user name (usually not your first and last name), your email address and other required details in the form below.
User Name:
If you do not want to register, fill this field only and the name will be used as user name for your post.
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

Posting Rules
You may post new threads
You may 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 Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Calculating HP for my engine glessen Engine 1 08-29-2006 12:24 PM
HP calculating PHATHOM Engine 0 06-06-2006 12:19 PM
calculating piston dish cc? firechicken383 Engine 2 06-13-2005 09:16 PM
Calculating speed Novaman78 Transmission - Rearend 5 03-06-2004 09:08 AM
calculating cruise RPM? laitch Engine 4 01-28-2004 09:18 AM


All times are GMT -6. The time now is 09:17 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
Copyright Hotrodders.com 1999 - 2012. All Rights Reserved.