- Joined
- Feb 29, 2012
- Messages
- 1,582
- Reaction score
- 8
- Location
- SoCal
- My Car
- 73 Mustang Convertible
Born an I-6, spent the teenage, 20 and 30 years as a 302, but at 40 will reach full potential as a 351C.
MEASURING COMBUSTION CHAMBER VOLUME
Most sites use window cleaner and a syringe. I don't have a syringe, so I did this using stuff around my house:
MATERIAL
Head With Valves, No Spark Plug
Oil- Kroil, WD-40, equivalent.
Plumbers Putty- Any material that is pliable, non water soluble, easy to remove from oily metal.
Straight Edge- Metal preferred, paint stick probably ok.
Measuring Cup- Tall with straight sides, minimum 4 Oz. or 120cc(ml).
Toothpick
TIME
15 Minutes, including clean up.
BACKGROUND
I bought my heads in 2008 and just recently rebuilt them:
Based on identifying marks(D0AE G) my heads were cast in 1970 and are spec'd with a quenched combustion chamber volume of:
63-68cc=65.5cc +/- 5%
But I trust no one, so I decided to measure them myself.
PROCEDURE
1. Oil, Oil, Oil combustion chamber. I used KROIL. This will allow easy removal of putty later. Alternatively, you can lay a sheet of plastic wrap down over the chamber. This way the putty never touches the head.
2. Take about 3 fluid ounces of plumbers putty, roll it into a nice ball removing all air and stuff the chamber.
3. Using the straight edge, tap the putty down into the chamber and remove excess. Basically float the straight edge over the head so there is no putty above the head. The more precise you perform this step, the more precise your measurement of chamber volume.
4. Remove putty from chamber. If it breaks apart, no big deal. It all gets clumped together later anyway. Be sure to remove as much as you can. Some will probably stick around the valve. You can use a toothpick to scrape it out. Better to remove it now for measuring. Break off the putty formed from the spark plug hole and discard it.
5. Measuring PRECISELY, put 30-50 CC of water in your measuring cup. If you don't have CC on your cup, try 1.5 oz of water. This should be very precise. But if you screw up, don't worry. You can always re-use your putty. Just remember EXACTLY HOW MUCH WATER you started with. I started with 50cc.
6. Hand mold your putty to fit into the measuring cup so it just BARELY misses touching the sides.
7. Insert the putty into the measuring cup so the putty is below the water line and there are no air bubbles in the putty. Minimize loss of water on your hands from forming the putty. If water spills out for any reason, simply remove the putty, and repeat step 5...maybe with a little less water.
8. Measure. Looks like 118cc to me.
9. Using the principle established by Archimedes in 250BC(so they say)
take the measurement in 8 and subtract the measurement in 5. For me that is 118cc-50cc=68cc.
If you are measuring in ounces, there are 29.6cc per oz.
If you are measuring in teaspoons, there are 4.92cc per teaspoon.
10. Now, most importantly, go back and CLEAN THAT COMBUSTION CHAMBER...and then clean your wife's measuring cup.
Most sites use window cleaner and a syringe. I don't have a syringe, so I did this using stuff around my house:
MATERIAL
Head With Valves, No Spark Plug
Oil- Kroil, WD-40, equivalent.
Plumbers Putty- Any material that is pliable, non water soluble, easy to remove from oily metal.
Straight Edge- Metal preferred, paint stick probably ok.
Measuring Cup- Tall with straight sides, minimum 4 Oz. or 120cc(ml).
Toothpick
TIME
15 Minutes, including clean up.
BACKGROUND
I bought my heads in 2008 and just recently rebuilt them:
Based on identifying marks(D0AE G) my heads were cast in 1970 and are spec'd with a quenched combustion chamber volume of:
63-68cc=65.5cc +/- 5%
But I trust no one, so I decided to measure them myself.
PROCEDURE
1. Oil, Oil, Oil combustion chamber. I used KROIL. This will allow easy removal of putty later. Alternatively, you can lay a sheet of plastic wrap down over the chamber. This way the putty never touches the head.
2. Take about 3 fluid ounces of plumbers putty, roll it into a nice ball removing all air and stuff the chamber.
3. Using the straight edge, tap the putty down into the chamber and remove excess. Basically float the straight edge over the head so there is no putty above the head. The more precise you perform this step, the more precise your measurement of chamber volume.
4. Remove putty from chamber. If it breaks apart, no big deal. It all gets clumped together later anyway. Be sure to remove as much as you can. Some will probably stick around the valve. You can use a toothpick to scrape it out. Better to remove it now for measuring. Break off the putty formed from the spark plug hole and discard it.
5. Measuring PRECISELY, put 30-50 CC of water in your measuring cup. If you don't have CC on your cup, try 1.5 oz of water. This should be very precise. But if you screw up, don't worry. You can always re-use your putty. Just remember EXACTLY HOW MUCH WATER you started with. I started with 50cc.
6. Hand mold your putty to fit into the measuring cup so it just BARELY misses touching the sides.
7. Insert the putty into the measuring cup so the putty is below the water line and there are no air bubbles in the putty. Minimize loss of water on your hands from forming the putty. If water spills out for any reason, simply remove the putty, and repeat step 5...maybe with a little less water.
8. Measure. Looks like 118cc to me.
9. Using the principle established by Archimedes in 250BC(so they say)
take the measurement in 8 and subtract the measurement in 5. For me that is 118cc-50cc=68cc.
If you are measuring in ounces, there are 29.6cc per oz.
If you are measuring in teaspoons, there are 4.92cc per teaspoon.
10. Now, most importantly, go back and CLEAN THAT COMBUSTION CHAMBER...and then clean your wife's measuring cup.
Last edited by a moderator:
