How to find piston CC? I have measurments - 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> Engine
User Name
Password
lost password?   |   register now

Reply
 
LinkBack Thread Tools
  #1 (permalink)  
Old 12-12-2012, 10:07 PM
Registered User
 
Last photo:
Join Date: May 2012
Posts: 51
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
How to find piston CC? I have measurments

I would like to know how to find what the CC of this dished piston is. Says the dish is 0.080in deep and 3.020in in diameter. Can anyone help me out here? I did try contacting the manufacturer but they didn't tell me anything.

Speed-Pro Digital Diamond Profile (DDP) Hypereutectic Pistons ZH815ACP30 - SummitRacing.com

    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 12-12-2012, 10:16 PM
cobalt327's Avatar
WFO
 
Last wiki edit: Intake manifold
Last journal entry: 1980 Malibu Wagon
Last photo:
Join Date: Mar 2009
Location: Atlanta
Age: 59
Posts: 5,037
Wiki Edits: 1616

Thanks: 128
Thanked 597 Times in 546 Posts
Quote:
Originally Posted by gsoleski View Post
I would like to know how to find what the CC of this dished piston is. Says the dish is 0.080in deep and 3.020in in diameter. Can anyone help me out here? I did try contacting the manufacturer but they didn't tell me anything.

Speed-Pro Digital Diamond Profile (DDP) Hypereutectic Pistons ZH815ACP30 - SummitRacing.com
Right at 11-12cc.
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 12-13-2012, 04:19 AM
Registered User
 
Last photo:
Join Date: Oct 2007
Location: Portland,Or
Posts: 838
Wiki Edits: 0

Thanks: 0
Thanked 43 Times in 37 Posts
You put the piston exactly 1 inch down in the bore, and then fill the volume with your burette. Measure the volume. Then calculate the volume of a 1 inch cylinder at your bore diameter. Dished piston will read more, domed piston will read less than your calculated volume.
Need this.

Closer view of burette.
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 12-13-2012, 11:20 AM
Registered User
 
Last photo:
Join Date: Apr 2007
Location: Seattle, Wa
Posts: 6,855
Wiki Edits: 0

Thanks: 4
Thanked 457 Times in 392 Posts
Quote:
Originally Posted by gsoleski View Post
I would like to know how to find what the CC of this dished piston is. Says the dish is 0.080in deep and 3.020in in diameter. Can anyone help me out here? I did try contacting the manufacturer but they didn't tell me anything.

Speed-Pro Digital Diamond Profile (DDP) Hypereutectic Pistons ZH815ACP30 - SummitRacing.com
To get there long hand:
Take the diameter of 3.020 inches divided by 2 which equals 1.51 inches.
Square that result (1.51 times 1.51) equals 2.2801 square inches.
Take that result whcih really is the area of a square with 1.51 inch sides and multiply by pi which 3.1416 is close enough this equals 7.1632 square inches.

To get the volume; the area is multiplied by the depth so 7.1632 square inches times .080 inch equals .5731 cubic inches.

Conversion to cubic centimeters is 16.4 cubic centimeters to the cubic inch. So .5731 cubic inches times 16.4 cubic centimeters per cubic inch equals 9.3981 cubic centimeters.

This same pattern can be used to compute the swept area the piston makes in bore and stroke, it will compute the clearance volume of the piston crown to block deck, and it is used to roughly compute the volume of the head gasket. Head gaskets often aren't actually round, but the computation will be damn close.
Piston domes and combustion chambers need to be measured unless you're really adept at calculus and want to spend a day doing integrations, if not, buy a graduated cylinder and some colored alcohol.

Bogie

Last edited by oldbogie; 12-13-2012 at 11:27 AM.
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 12-13-2012, 07:07 PM
cobalt327's Avatar
WFO
 
Last wiki edit: Intake manifold
Last journal entry: 1980 Malibu Wagon
Last photo:
Join Date: Mar 2009
Location: Atlanta
Age: 59
Posts: 5,037
Wiki Edits: 1616

Thanks: 128
Thanked 597 Times in 546 Posts
The valve reliefs go below and outside of the circle's diameter.

I have CC'd a piston having a 0.080" deep dish, but w/o the deeper valve reliefs like that piston seems to have (if the Summit photo is actually representative of the piston and not a stock photo). The volume for that Chevrolet production piston is 11cc.

The piston in question will have a slightly larger volume than the GM piston, if the reliefs are actually as depicted in the Summit photo. That's why I added "11-12cc" to my answer. In actuality the volume is probably a bit more than 12cc.

More: Dish volume

Last edited by cobalt327; 12-13-2012 at 07:16 PM. Reason: Add link.
Reply With Quote Quick reply to this message
  #6 (permalink)  
Old 12-13-2012, 08:53 PM
cobalt327's Avatar
WFO
 
Last wiki edit: Intake manifold
Last journal entry: 1980 Malibu Wagon
Last photo:
Join Date: Mar 2009
Location: Atlanta
Age: 59
Posts: 5,037
Wiki Edits: 1616

Thanks: 128
Thanked 597 Times in 546 Posts
Quote:
Originally Posted by cobalt327 View Post
The volume for that Chevrolet production piston is 11cc.
That included the valve reliefs, BTW.
Reply With Quote Quick reply to this message
  #7 (permalink)  
Old 12-14-2012, 11:14 AM
Registered User
 
Last photo:
Join Date: May 2012
Posts: 51
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Thanks for the help guys appreciate it. So I put 11.5 in the compression calculator and with the set up i'd have I would get 9.99:1 with piston 0.035 in the hole (lower compression distance right?) and a felpro 0.015 head gasket. Then 10.2:1 with a zero deck and the felpro 0.039 head gasket. I know 0.040 quench is what you want but would the higher compression be okay with my vortec heads and 91 octane? My heads were milled to 59cc by the way
Reply With Quote Quick reply to this message
  #8 (permalink)  
Old 12-14-2012, 01:56 PM
techinspector1's Avatar
Senior Curmudgeon
 
Last wiki edit: DynoSim combinations Last photo:
Join Date: Oct 2005
Location: Hemet, California, USA
Age: 72
Posts: 12,977
Wiki Edits: 326

Thanks: 765
Thanked 1,023 Times in 855 Posts
Let's call the cylinder volume 727.4 cc's.
Piston crown 11.0 cc's
Chambers 59.0 cc's
Piston deck height 7.3 cc's @0.035".
Gasket (0.015"/0.016") 3.3 cc's
Total 808.0 cc's
Total less cylinder 80.6 cc's
Divide the larger by the smaller and find 10.02:1 static compression ratio with ~0.050" squish.
If I could check both decks and both heads with a precision machinist's straightedge and found that all surfaces were flat within 0.002" and I was on a tight budget, that's how I'd build the motor. I might use a cam something like this one that closes the intake valve at 42 degrees ABDC.
Crane Hydraulic Flat Tappet Camshafts 114561 - SummitRacing.com
This cam would generate a dynamic compression ratio of 8.46:1, which I feel would work with pump gas and a 0.050" squish. You'll need to use more ignition timing at the crank and curve the weights in the dizzy for max 34 degrees, all in by 2800. I think I'd use a 3500 stall converter.

If any decks were wavy beyond 0.002", I would not use a steel shim gasket without cutting the decks/heads for flat.

DanielC, you are correct, with a dish shaped like this, math won't get you there, you should pour the crown with alcohol. You do not, however, have to position the piston down in the bore by 1". This will keep you filling the burette too many times and allow an error. You only need the piston down in the bore far enough for fluid to flow across the crown, like say 0.030". Then you do the math as if the dish were not there to find the volume of that space: (.7854) x 4.03 x 4.03 x .03 x 16.387, which would calculate to 6.27 cc's. You would write that down and then pour the volume. If, for instance, the fluid required to fill the dish and crown was 17.5 cc's, then you would subtract 6.27 from 17.5 and find a dish volume of 11.23 cc's.

Last edited by techinspector1; 12-14-2012 at 02:08 PM.
Reply With Quote Quick reply to this message

Recent Engine 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
How to take these Measurments. satexasf150 Body - Exterior 20 03-05-2007 08:10 PM
model a cowl measurments spud Body - Exterior 2 08-08-2006 02:32 AM
About Wheel measurments DV8 General Rodding Tech 1 10-13-2005 07:32 PM
measurments for a rearend 50chevyfastback Transmission - Rearend 2 10-04-2002 12:19 PM
'30-'35 measurments WANTED Halloweenking Hotrodders' Lounge 2 08-25-2002 09:45 PM


All times are GMT -6. The time now is 01:30 PM.


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.