DIY Write Up - HOW TO CC YOUR COMBUSTION CHAMBER
#1
Honda-Tech Member
Thread Starter
iTrader: (1)
Join Date: Oct 2003
Location: Boston
Posts: 434
Likes: 0
Received 0 Likes
on
0 Posts
DIY Write Up - HOW TO CC YOUR COMBUSTION CHAMBER
I was trying to calculate the compression ratio and after doing a lot of estimating, I had a broad idea where it would be but I realized that there really is no way around actually ccing the head to find a more realistic number. I found that it can be done yourself without spending very much money.
HOW TO: CC YOUR COMBUSTION CHAMBER
Materials
1. Liquid (Best to use something slightly thicker than water and colored)
2. 60 ml Syringe (1ml=1 cc)
3. Petroleum Jelly
4. A piece of plexiglass
I decided to use some water wetter + water since it was laying around.
Clean the subject combustion chamber using solvent, clean shop rag, air pressure etc. before you begin. Install the spark plug you will be using.
Apply the petroleum jelly to the cylinder head surface around the combustion chamber to create a seal with the plexiglass.
Put the plexiglass on the cylinder head and make sure it seals to the surface.
Cover the chamber except for a small amount at the end where you will fill the chamber with liquid.
Fill the 60ml Syringe with liquid to 50ml or any starting amount, making sure you get all the air out.
Fill the combustion chamber slowly. Move the plexiglass around to get any bubbles out if necessary.
Carefully fill the chamber until you can just slide the plexiglass over the liquid with no air bubbles.
Now your combustion chamber is full.
Subtract whats left in the syringe from what you started with and that's the size of your combustion chamber. I would recommend repeating a few times just to verify results. For a more exact result a lab pipette could be used.
Here's a quick Static CR Calc for my particular build. The piston-to-deck height was measured at about 0 so the volume was negligible. In this particular application the head was milled .020" as well. CR should be between 11.55:1-11.65:1.
HOW TO: CC YOUR COMBUSTION CHAMBER
Materials
1. Liquid (Best to use something slightly thicker than water and colored)
2. 60 ml Syringe (1ml=1 cc)
3. Petroleum Jelly
4. A piece of plexiglass
I decided to use some water wetter + water since it was laying around.
Clean the subject combustion chamber using solvent, clean shop rag, air pressure etc. before you begin. Install the spark plug you will be using.
Apply the petroleum jelly to the cylinder head surface around the combustion chamber to create a seal with the plexiglass.
Put the plexiglass on the cylinder head and make sure it seals to the surface.
Cover the chamber except for a small amount at the end where you will fill the chamber with liquid.
Fill the 60ml Syringe with liquid to 50ml or any starting amount, making sure you get all the air out.
Fill the combustion chamber slowly. Move the plexiglass around to get any bubbles out if necessary.
Carefully fill the chamber until you can just slide the plexiglass over the liquid with no air bubbles.
Now your combustion chamber is full.
Subtract whats left in the syringe from what you started with and that's the size of your combustion chamber. I would recommend repeating a few times just to verify results. For a more exact result a lab pipette could be used.
Here's a quick Static CR Calc for my particular build. The piston-to-deck height was measured at about 0 so the volume was negligible. In this particular application the head was milled .020" as well. CR should be between 11.55:1-11.65:1.
Last edited by deckster333; 09-17-2010 at 07:38 AM.
#2
Honda-Tech Member
Re: DIY Write Up - HOW TO CC YOUR COMBUSTION CHAMBER
Nice write up.
If you don't have water wetter or coolant lying around. A mixture of water, food colouring and alcohol works very well. The alcohol reduces the surface tension of the fluid. Another hint would be instead of filling it from the side and sliding the plexi over. You could try drilling a hole in the center of the plexi so that you don't have to move it once it's sealed in place. Remember to CC all 4 chambers as they may differ slightly.
If you don't have water wetter or coolant lying around. A mixture of water, food colouring and alcohol works very well. The alcohol reduces the surface tension of the fluid. Another hint would be instead of filling it from the side and sliding the plexi over. You could try drilling a hole in the center of the plexi so that you don't have to move it once it's sealed in place. Remember to CC all 4 chambers as they may differ slightly.
#3
Honda-Tech Member
Join Date: May 2006
Location: Cary, NC, usa
Posts: 652
Likes: 0
Received 0 Likes
on
0 Posts
Re: DIY Write Up - HOW TO CC YOUR COMBUSTION CHAMBER
Nice write up, thanks for posting this. I was searching around yesterday for a good article/post on this. I found a couple but not many with good pics.
Trending Topics
#9
Honda-Tech Member
Thread Starter
iTrader: (1)
Join Date: Oct 2003
Location: Boston
Posts: 434
Likes: 0
Received 0 Likes
on
0 Posts
Re: DIY Write Up - HOW TO CC YOUR COMBUSTION CHAMBER
Glad this is helpful!
A good question. Since it seems people are going to be referencing the calcs I adjusted them so they are easier to understand. The .00025 I was using is just a condensed version of the area formula multiplied by the cubic mm to cubic cm conversion. ((Pi)*((d/2)^2))/1000=0.00025
Also OEM headgasket range is 0.660mm-0.740mm. I adjusted the thickness to .660mm which would be the smallest crushed thickness. But anywere within that range the CR won't really vary much.
Here is a good compression calculation thread for more info:https://honda-tech.com/forums/all-motor-naturally-aspirated-44/diy-compression-ratio-calculation-2476094/
Also OEM headgasket range is 0.660mm-0.740mm. I adjusted the thickness to .660mm which would be the smallest crushed thickness. But anywere within that range the CR won't really vary much.
Here is a good compression calculation thread for more info:https://honda-tech.com/forums/all-motor-naturally-aspirated-44/diy-compression-ratio-calculation-2476094/
Thread
Thread Starter
Forum
Replies
Last Post
redlineintegra
All Motor / Naturally Aspirated
3
06-19-2006 05:45 AM