
- Home
- Club Hot Rod Home
Welcome to Club Hot Rod! The premier site for
everything to do with Hot Rod, Customs, Low Riders, Rat Rods, and more.
- » Members from all over the US and the world!
- » Help from all over the world for your questions
- » Build logs for you and all members
- » Blogs
- » Image Gallery
- » Many thousands of members and hundreds of thousands of posts!
YES! I want to register an account for free right now! p.s.: For registered members this ad will NOT show
Latest PollShare your age Group for 2012 (105 Votes)
-
20's (3 Votes)
-
30's (5 Votes)
-
40's (11 Votes)
-
50's (24 Votes)
-
60's (42 Votes)
-
70's (20 Votes)
-
80's (0 Votes)
-
90's (0 Votes)
-
-
CHR Library Recent Articles
Random Pics From Gallery!
by One Arm Bandit
· · ·
Club Hot Rod Member Galleries
17068 photos
4414 comments
by TimothyPilgrim
· · ·
Club Hot Rod Member Galleries
17068 photos
4414 comments
by Diamond
· · ·
photos
comments
by FMXhellraiser
· · ·
Club Hot Rod Member Galleries
17068 photos
4414 comments
by OSK
· · ·
Club Hot Rod Build Pictures
703 photos
363 comments
by junkyardjeff
· · ·
Club Hot Rod Member Galleries
17068 photos
4414 comments
by cevan
· · ·
Club Hot Rod Member Galleries
17068 photos
4414 comments
by TMattin
· · ·
Club Hot Rod Build Pictures
703 photos
363 comments
Recent Activity
This Is Not A CraigsList Notice
Thread Starter: rspearsIt was suggested that we start a new thread for our off-topic discussions regarding the state of the union, world peace, cures for physical ailments...
ted dehaan Today, 05:00 PM
Street Rod Gal
Thread Starter: rspearsHad to grab a shot of our little lady this morning - explains itself, but she sure seems happy with Summit!!
Oldmanb Today, 03:55 PM
Kind Of A Drag
Thread Starter: Good WrenchI just took our heavy Chevy Monte Carlo to the track for the first time and averaged in the 15's (Boo Hiss) and that's even with using nos. Ok how...
Good Wrench Today, 03:40 PM
Triangulated 4 Bar Housing Brackets
Thread Starter: gearjammerI'm in the process of changing my rear end and I need some new Triangulated 4 Bar Housing Brackets, does anyone know where I can buy just the...
gearjammer Today, 03:36 PM
sealant for natural gas
Thread Starter: Dave SeversonBroke down and got me a new heater today. Reading through the directions on sealing the natural gas supply line it states, "sealant, resistant to...
rspears Today, 03:27 PM
Go 4 a ride to car,bike and food show w/ my son and I.
Thread Starter: The BatHope ya enjoy the ride? Food Trucks, Car Show & Bikes, THURSDAYS @Tropical Park - YouTube :cool::3dSMILE:
rspears Today, 02:12 PM
37 Ford build--IE: old Header issues thread /37 Ford/5.0/GT40P heads
Thread Starter: randyrHey guys, I'm new to this forum and have a question to run by you guys. I have a 37 Ford tudor with a '69 302, C4 auto, 9" rear. I'm currently...
IC2 Today, 02:05 PM
Need some basic information about adjusting my carb
Thread Starter: Slade1134My car is running entirely too rich. It svery strong. My dad says he was gonna adjust for me but hasnt yet (that was a month ago) I know how to...
rspears Today, 01:29 PM
Wheel Mounted "MINI-CLUB"
Thread Starter: rspearsWe all know that a car thief that decides he wants our car will likely get it at some point, but we take steps to slow them down or surprise them in...
rspears Today, 01:19 PM
Changed CPU's on the Server Tonight
Thread Starter: Brent MillsAs many of you have witnessed over the last couple of years, the server at times has been less than stable. While this has been a problem for you...
Brent Mills Today, 09:17 AM
Chr
Thread Starter: cffisherAm I the only one having trouble getting on ??Seems the last week it has been difficult getting on here...
Brent Mills Today, 09:14 AM
Rodrunners 32er rod build on Rover P2 chassis
Thread Starter: RodrunnerI would like to report about the construction of my own rod. Because my English is not perfect, please write English as simple as possible, if you...
Dave Severson Today, 09:05 AM
327 for 88 firebird
Thread Starter: viva la speedHello club hotrod, This is my first post here. My name is Nic and this is a build me and my old man are taking on together. Anyway down to the...
docwilcar Today, 08:21 AM
79 labaron for sale
Thread Starter: 36chevymasteri have a 79 labaron with 27000 miles. it has a slant 6. the car is in good to great condition. i am asking 2500.00 for it any questions please...
36chevymaster Today, 08:03 AM
rear window package tray
Thread Starter: dwaynerzwhat type of material are people using as rear window package tray board (?) luan? plastic? msd? mine iswall paneling that probably worked for the...
Proeagles Today, 07:47 AM
3-word story
Thread Starter: techinspector1On another forum, they started a 3-word story. You're only allowed to use 3 words in your reply and it can get pretty funny (and pretty stupid). I'll...
MelloYello Today, 04:48 AM
Overhead console build
Thread Starter: CreepI'm looking for some Ideas. To build my own overhead console. Any and all input welcome. Photo's would be great as well. Thinking about using plywood...
sunsetdart Today, 03:35 AM
41 Willys Gasser project
Thread Starter: roadster32I hope this of some interest. It will be a 60's style Gasser Due to the high cost of Willys replacement parts I will be using a mesh grill which...
lamin8r Today, 02:11 AM
Cam change...?
Thread Starter: Merc 006Ok...so I'm sure anyone reading this has seen my other posts. Oil dissapearing, low pressure, etc. Well, long story short: I change my valve...
Dave Severson Today, 12:44 AM
-
Club Hot Rod Home
by Published on 04-29-2011 12:41 AM Number of Views: 1915
Static compression ratio, domed pistons, how to figure the math.
We'll use a 454 Big Block Chevy for this explanation. Let's say we're using the stock bore and stroke of 4.250" and 4.000" and production cast iron heads with 122cc chambers. The pistons are down in the bore 0.025" (piston deck height) and have a dome volume of 28.7 cc's (get this info from the piston mfg or figure the dome volume yourself: See Determining Piston Dome Volume). To figure static compression ratio, you need 5 different values...
1. cylinder volume in cc's
2. combustion chamber volume in cc's
3. piston crown volume in cc's (+ or - or flat with eyebrows)
4. piston deck height volume in cc's (volume above the piston crown up to level with the block deck with the piston at TDC)
5. head gasket volume in cc's
Let's take these one by one so that you and others will know how to figure SCR with a domed piston....
1. We know that the bore is 4.250" and the stroke is 4.000", so we multiply (.7854 times 4.250" times 4.250" times 4.000" times 16.387) and find that there are 929.88 cc's in the cylinder.
2. Anyone building a motor should use a burette and colored alcohol to "pour" the chambers and determine the exact volume in each and every chamber (yes, they differ one to the other, but can be equalized prior to assembly), but I doubt that many of you fellows do that. These heads are advertised at around 119cc's, but production heads will usually pour a little bigger, so let's call them 122 for this exercise.
3. OK, we'll do a little play acting here. We will visualize taking a sharp instrument and slicing the dome off the piston, leaving only a flat plane crown with no eyebrows. So, here we are holding a lump of aluminum that displaces 28.7 cc's. We are now going to jam that lump up into the combustion chamber to reduce the chamber volume to 93.3 cc's. This will result in a piston crown value of zero.
4. We have no idea what the piston deck height is on this motor, but let's just use a theoretical value of 0.025". So, we have a bore of 4.250" and the piston is 0.025" in the hole at TDC. Remember, the piston is now a flat-top, so we will simply multiply (.7854 X 4.250" X 4.250" X 0.025" X 16.387) and find 5.81 cc's.
5. I'm going to assume that the decks of the block and heads are flat enough to use a Mr. Gasket shim head gasket, #1131, 4.370" X 0.020". This will put our squish at 0.045". Again, figuring cc's just like anything else that's round and has a thickness......(.7854 X 4.370" X 4.370" X 0.020" X 16.387) and find 4.92 cc's in the head gasket.
Now, we add all our values together....
929.88 + 93.3 + 0 + 5.81 + 4.92 and find a total volume of 1033.91 cc's.
Now, we will drop out the cylinder volume and add the other 4 values together....
93.3 + 0 + 5.81 + 4.92 and find a compressed volume of 104.03 cc's.
Now, we will divide the larger volume by the smaller volume (1033.91 / 104.03) and find 9.94:1 static compression ratio.
-
Currently Active UsersThere are currently 200 users online. 13 members and 187 guests
Most users ever online was 956, 08-12-2008 at 07:23 PM.
- 1gary
- BIGBLOCK
- DA34GUY
- echnidna
- Hoss Blazer
- IC2
- Mike P
- NTFDAY
- pat mccarthy
- ptcrzr
- rspears
- shine
- ted dehaan
Latest VideosRecent Article Comments Widget
well that only works when you have the cc of the dome :LOL: nice but if you do not have the cc of...
Static compression ratio, domed pistons, how to figure the math.
pat mccarthy on 01-23-2012Recent Blog Posts
gas filler/ cap for sale
This is a complete Jaguar gas cap assembly including the key that would be perfect for a hot rod. I'm asking $65, please let me know if you're interested. email bobbrown@remax.net Thanks, ...
Bob B 01-27-2012Everybody that is currently building a car...
35 had a lot going on this year , house remodel , new garage finally and knee surgery that still is off , Slows us down a might .
bluestang67 01-26-2012
How to wire an electric fuel pump
Well I won't be trying that after all. There are only 4 post on the relay
1ducatiboy 01-24-2012
34 ford with a complete 2007 corvette drivetrain
I am putting together a 34 ford (fiberglass) with a corvette c-6 drive trainMotor,torque tube,6 speed auto and indipendent rear.I built a custom frame for it of course, and now I would like to make...
glenn somers 01-23-2012
any power tours this year?
I was looking for a good power tour to do. I live in suburbs of Chicago
WALTERBRATCHER 01-14-2012
Weather Widget
Copyright © 2012 vBulletin Solutions, Inc. All rights reserved.
Content Relevant URLs by vBSEO 3.6.0
Tabs System by vbSoporte - vBulletin en Espaņol
vBulletin Styles developed by vBStyles.com




I wish I had the money for a prodject Like my friend Gary Gillbert is working on.
Thread Starter: vara4Rear engine dragster, HUMMM!!! Flickr: kurtvara's Photostream
ted dehaan Today, 05:08 PM