cc your cylinder heads, combustion chamber, or piston dome , or port volume


Staff member
CC'ing a cylinder head is a process that measures the volume of the combustion chambers in the cylinder head. The term CC'ing is referring too the cubic centimeters of the pocket (combustion chamber). the purpose of cc'ing the head is to determine the size of the combustion chambers so they can be equalized, resulting in a consistent cylinder to cylinder compression ratio of the engine. You cannot accurately compute the compression ratio if you do not know the exact size of your combustion chambers. Also it is important in performance heads to have equal cc'ed heads to balance the engines compression to each cylinder, so the stress levels and power produced in each cylinder put equal levels of stress on the crank, and block for better durability.
youll want too have a fluid with little or no surface tension ,
rubbing alcohol with food coloring will work.

most grocery stores sell food dye


and rubbing alcohol
( but you might prefer water,
and a drop of dawn dish washing soap,
and food coloring
(because alcohol dissolves some plastics (
and its very flammable unlike water with food dye)


don,t work near flames or ignition sources alcohol like gas can ignite starting a fire and alcohol flames are difficult to see in bright light, but still very


youll need a very consistent and accurate burret
(or TWO if lets say your measuring a BBC head with a 120cc combustion chamber and you only have a 100cc burret)
(ideally holding a good deal more volume than the area being measured)
if your measuring a 62 cc combustion chamber youll ideally start with it dry and sealed off and use a 100cc-250cc burret, you,ll fill it to lets say 100 cc,and it helps to have a good stable burret stand to hold the burret vertically
(look at this picture)

I'd point out that you,ll need accurate measuring tools for the volume of the fluid that your using to accurately fill the space or volume that that fluid is too fill.
the clear glass or lexan plate must be sealed to the head surface with a very thin layer of clear grease like Vaseline, to prevent leaks of the measuring fluid and the entrance hole you use too fill the area measured must be very close to level with that fill hole being located at the very upper edge of that area being filled and measured.
CCING heads is a process where your attempting to measure the volume or three dimensional volume of the port or combustion chamber ETC. your trying too verify to see if its volume is equal too or lessor or greater than the other similar volumes, in an attempt to equalize all of them to generally match , by removing metal from smaller combustion chambers so that they will all match the largest original combustion chamber in most cases.
(you can,t logically make changes until you carefully verify all 8 combustion chambers and label each and accurately measure and verify each one.)



before you remove any volume or change any combustion chamber you must seal the valves and spark plug threads with a sealant along the valve seat , and valve bevel edges, and spark plug threads, so no measuring fluid can seep out making the measurements less accurate or worthless
When you CC heads, BE sure the glass or lexan is not allowing some of the measuring liquid to seep out of the combustion chamber, under the glass or lexan , or the sealant between the glass is not being displaced into the combustion chamber, thus giving you a false volume.
(getting some sealant squeezed into the combustion chambers, or fluid leakage is (VERY EASY TO DO)
ID suggest looking carefully at both potential reasons for the variation in measured combustion chamber volume
so Id use a tiny bit of sealant grease (a bit of Valvoline works if you use colored water, with a drop of dawn dish was liquid to destroy surface tension)
but alcohol with a bit of food color dye works best as it evaporates rapidly after use and is less likely to cause dust rust on surfaces after use.

you'll obviously want to open up the smaller combustion chambers a bit, and un-shroud the valves and try to match the largest chamber size.
valve to valve seats should provide an alcohol tight seal,if they don,t you really should lap the valve seats or get a machine shop to do the valve job correctly ,
a q-tip's worth of vaseline, carefully applied before you cc a port or valve, or combustion chamber etc. can be used to provide a valve stem to valve guide , or valve seat to valve sealant

ChamberCCs01.jpg ... m#cxrecs_s





yes once again reading thru the linked info will provide a great deal more useful info.

viewtopic.php?f=52&t=4715&p=12810#p12810 ... asure.html ... ksheet.pdf

http://www.compperformancegroupstores.c ... linderHead

viewtopic.php?f=53&t=110&p=1672&hilit=4032#p1672 ... index.html ... ctions.pdf

http://www.compperformancegroupstores.c ... linderHead

http://www.compperformancegroupstores.c ... linderHead ... s/ph16.pdf ... m#cxrecs_s



you might want to read this link while your at it

Powerhouse's New Pro Head CC Kit
Engine builders and machinists use the process of cc'ing a cylinder head to measure the volume of combustion chambers in the head for the purpose of ensuring all combustion chambers in the engine are the same size as well as determining compression ratio. However, not all cylinder heads, or engines for that matter, are of equal size. That's why Powerhouse Products has gone out of its way to ensure that the needs of the customer are met, by offering its Pro Head CC Kit in various sizes. In addition to the different sizes, Powerhouse Pro Head CC Kits provide everything you need to properly cc cylinder head combustion chambers, intake and exhaust runners, intake manifolds, and/or cylinders. The precision glass burettes are compatible with alcohol, parts washers, or any other solution one can use. With no math involved, the kit's easy-to-read scales are marked off in 0.2cc increments (except the 250cc model) and actually read out the amount you have poured. For more information, please go to

intake and exhaust port volume is measured with a CC-ing burret and some colored liquid the same way that combustion chamber volume is measured , the intake , or exhaust port being measured, gasket surface must be flat level and facing vertically and the valve must seal and hold the liquid from leaking, you can't just measure the intake port opening because depth and contour and lengths vary considerably






I think back on the many dozens of times Ive pocket ported,heads un-shrouded combustion chambers, port matched, intakes and checked deck to piston heights
and I can,t help but grin, if you guys are discussing the potential for mis-reading the burret level when CCing your cylinder heads , ... clnk&gl=us
a potential mistake that might result in a 1/2cc difference, now in an ideal world we all strive to get things exactly correct, but,


lets assume you do find a full cc difference ,between combustion chamber volumes,the real question is, what do you do to correct that, mis-match and if you don,t how much does it matter, to your engines performance?

input your average 70cc sbc heads on a 9:1 cpr sbc then change the chamber volume 1 cc and see how it changes the true results, in most production engines youll be very lucky to be within that range




USE THE CALCULATORS to match port size to intended rpm levels... but keep in mind valve lift and port flow limitations ... ch_engine/

it should be rather obvious that youll need to know the exact distance the piston deck sits at TDC ,above or below the block deck surface and the valve notch recess or pop-up dome volume of the piston to do accurate quench or compression calculations

keep in mind any valve clearance recessed areas must have the areas shrouding flow blended to increase rather than restrict air flow and to reduce the potential for detonation that sharp exposed edges tend to have


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Staff member
Re: cc your cylinder heads*

some tips posted by TOYzRme

"Couple tips to add for cc-ing.

Go lightly on the grease on the valve face. Extra grease oozes into the chamber, takes up liquid space, and falsely reduces cc slightly. Same with grease around the chamber between the plexiglass and the head. Thin coat here.

Use a little grease on the spark plug threads, too. They will leak.

Tip the head slightly with thin wood shims (paint stirrers, etc) so that one edge of the chamber is higher than the opposite side. Put the hole in your plexiglass right at the edge on the high side. When you're close to full, the last air bubble will be easier to get out if it is along the edge, and the hole is at the high point. If the head is level, or the hole is in the middle of the chamber, it's a pain in the butt to try to get the last of the air bubbles out.

If you're using a burette with 100cc or less, you'll probably have to fill it twice. Be sure to "0" the fluid level by overfilling slightly and draining to the "0" mark each time before you start a pour.

The first pour, for example, would be 100cc with a 100cc burette. Then, fill it again, zero by draining a little out, and pour till full. The second pour may only take 10-20cc.

When you're ready to drain a chamber, just take out the spark plug. It's easier to control where the fluid goes instead of it gushing out of an opened valve and port.

Don't forget to number the chambers, and record the measurements!

Be careful with the tip and valve of the burette, if it is glass. They are pretty fragile."
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Staff member
Re: cc your cylinder heads
head gaskets are rarely completely round, nore are combustion chambers
you,ll want to place a head gasket you,ll use on the heads and mark the area inside the opening as the only areas you can change,
(notice the gasket fire ring is NOT a perfect circle like many people assume)
ideally you,ll want to un-shroud the valves while opening up the combustion chamber volume,
but not extend the combustion chamber past the front edge of the gasket fire ring,
as that usually causes gasket failure


you might be amazed at how much material can be removed ,
too noticeably increase air-flow and un-shroud the valves,
and how little it might effectively change,
the combustion chamber volume and compression.





posted by CCDUDE
"The best and correct way to measure the effective dome volume of your piston is very simple! First start with the tools of the trade. You will need a burette of adequate volume to hold enough solvent or your fluid of choice,probably at least 100cc's. Then put the top ring on the piston. Then get some medium density grease and lightly coat the inside of the cylinder you choose to insert the piston into for checking. Don't overdo the amount of grease you apply to the cylinder bore, just apply enough to allow a good seal around the edge of the piston. If you have a depth mic or dial caliper, make sure that the piston is square in the bore(be as precise as possible to the .001 if you can) by a predetermined depth(.500 or .750,etc..). This of course will be determined by the actual height of the dome. Make sure that it is only slightly lower than the top of the deck, but equal at 90 degree spacing. Now, take a Q-Tip or other slim dowel with a kleenex wrapped around the tip to now remove the excess grease from around the piston edge and cylinder bore.Any remaining grease will count toward piston volume,so be thorough and remove as much as possible. Double check that your piston is still square and hasn't been moved by your grease removal. Now you will need a piece of plexiglass or lexan that will cover the entire bore. This plate should have 2 holes drilled into it, one for the tip of your burette to fit into, the second will be for a vent to help eliminate air pockets as the cylinder fills. Lightly run a bead of grease around the top of the cylinder with your fingertip to seal the plexiglass plate. Make sure grease doesn't ooze into the top of cylinder, this again will add to the piston volume that you measure and give you an inaccurate reading. Now fill your burette with your fluid(I use varsol or safety kleen), and zero the reading with the petcock. You may have to practice a few times. The fluid in the burette will appear to be curved on the bottom edge of the level, this is normal(its called a miniscus),that your reading at the bottom edge of it. Now slowly fill the cylinder with your burette. As the cylinder becomes full, and your close to topping it off,allow any air bubbles to find their way to the vent hole and escape. Then, top the level off just to the bottom of your plate and not up the holes in the plate. Also check for leaks, you will know by now if you have any! Take the reading in cc's from your burette and write it down. You need to know the exact bore size of the cylinder down to the .001th. Use this formula to calculate the volume the bore should be without the dome present: .7854 x bore x bore x depth of piston in bore(your measured depth with depth mic). Now subtract your cc'ed volume from the calculated volume and this is your piston dome volume(Finally)! Now you can plug all those #'s into your compression formula and see what you have!"

The piston manufacturer should have the compression ratios listed for all of their pistons in their specs. obviously your true cpr,depends on the combustion chamber size of the head, head gasket thickness and the deck height of the block. Usually, the manufactures specs are close, but after head milling and block decking,milling heads,un-shrouding valves etc, its not going to be exactly accurate, on every application.

Probably the more important thing to check is the "quench" distance. Its the distance between the outer flat edge of the piston from the gasket surface of the head. Engines seem to work best with that distance set at .042-.044". That distance includes the head gasket thickness too. Most machine shops should be able to check this measurement and cc your heads and piston dome volume,and make the necessary block deck milling operations to achieve that distance, with a decent quality head gasket of a know easy to acquire brand.

To accurately calculate compression ratio, you must know several things:
1) The bore of the cylinder
2) The stroke of the cylinder
3) The volume of the combustion chamber
4) The compression height of the piston (Ask for this from the piston manufacturer)
5) The dome/dish volume of the piston (Ask for this from the piston manufacturer)
6) The piston-to-deck clearance
7) The thickness of the head gasket
8) The bore of the headgasket

viewtopic.php?f=52&t=727 ... index.html



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Staff member
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Staff member
Re: cc your cylinder heads


if you really want to get the compression calculations correct youll want to cc the piston dome (popup or valve notches)
youll need to grease the bore perimeter while the pistons down the bore about 2" then bring it up to exactly 1" from the deck and use a finger tip of grease to seal the space between the bore wall and piston , smear it to seal the bore for accurate measurements, obviously that makes calculating the volume of a 1" bore size cylinder fairly easy then you measure the required fluid volume to compare it to the calculated voluum to get the difference.



obviously after cutting the correct valve notch clearances and machining the dome for spark plug clearance, its not going to be at factory volume and even if it was my experience shows the posted data is rarely correct


you could find out the popup piston dome volume, of an unknown piston dome in a very similar manor,
Set the piston down the bore at a precise depth, low enough to place the top of the piston dome below the block deck height,make 100% sure that bank of cylinder bore decks are exactly level so any liquid you use will fill to the top of the bore wall and measure with,will evenly fill the bore from any angle.- calculate that volume (bore*bore*3.14/4 times your set depth, the piston is down the bore, (1" is what I generally use.), then seal the piston to the bore wall with vasoline petroleum grease or moly axle grease to fill in the piston to bore gape over the first compression ring, just enough for sealing while leaving no extra in the bore (your finger then Q-TIPS WORK GREAT), put a sheet of plexiglass or acrylic plastic (sealed with petroleum grease) with a drilled filling hole, then fill the area around the piston dome with alcohol with a few drops of food coloring (any bakery or super market has this)as it evaporates rapidly and measures easily in a burret mixed with solvent from a proper burette or a graduated cylinder. Subtract the two volumes, and you get the net difference, or the piston dome popup volume of the piston. If you fill the valve dishes with grease, you'll get the nominal popup volume and you get the valve recesses too.

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Staff member
Re: cc your cylinder heads

chuckd396 said:
I have a 396 engine to what I have assumed is a 2 barrel engine 265 hp. I want to ditch the 148 heads and install 063, 215, or 290 heads with the 101cc closed chamber which should bring my compression up about 1 point from where its at stock of 9:1.
Can anyone confirm this info?
Block casting # 3955272
Heads casting # 3933148
Ok I have heard 122cc chambers and also 112cc chambers from several sites. Can you explain
why there are two different numbers out there?

3933148 366/396/427 69 2.06/1.77 122cc Oval port
3955272....396.......69......2 or 4 bolt



those open chamber oval ports may be down on compression but they BREATH BETTER than the closed chamber versions as there chambers design shroud the valves less, personally id rather use those current heads and do some port and bowl area clean-up work and compensate for the lower compression with better scavenging , with long tube headers and a low restriction exhaust, and a cam with a fairly tight LSA in the 108 range and what I generally do to a 396 ,which is install a cheap 454 crank and build a 434 stroker which both also significantly boosts torque and compression

viewtopic.php?f=69&t=2165 ... defc383645

the sites quoting 112cc or 122cc may be a miss print,in any case it won,t take long to measure a set and find the true chamber volume so your not guessing,or taking the word off some chart rather than dealing with a proven fact yes theres occasionally minor block clearance work,to fit the 454 stroke crank, but most times not,depends mostly on the connecting rods used and yes the assembly needs to be rebalanced,Ive generally used the 454 flexplate and balancer, getting 500hp out of a stroked 396/434 is hardly difficult if your willing to put some time and effort into researching the parts required and careful assembly

viewtopic.php?f=52&t=2077&p=5565&hilit=ccing+heads#p5565 ... cc+syringe

most drug stores sell 10cc syringes for LESS than $3, you can check your cylinder head easily, and cheaply by leveling the deck surface and carefully filling the combustion chamber with water with a few drops of dawn dish washing detergent to break the surface tension, it won,t be difficult to tell 112cc from 122 cc

Piston compression height is the distance between the centerline of the pin to the flat part of the top of the piston. It's important to know this number when ordering pistons--especially custom ones--so that the piston falls in the right place in relation to the deck surface of the block (where the cylinder head bolts on). To figure out the best compression height, you need to know your block's deck height, the length of your connecting rods, and your crank stroke.

Block deck height is the distance from the centerline of the main journals to the block deck surface. For example, the small-block Chevys we tested last month were delivered at 9.020 inches, though this is commonly machined to 9.00--and giving or taking that 0.020 really makes a difference.

So assume you have a block with a 9.00-inch deck height, 6.000-inch connecting rods, and a stroke of 3.75 inches. First, divide the stroke by two and add that to the rod length: 3.75 / 2 = 1.875, and 1.875 + 6.00 = 7.875. Next, subtract that answer from the deck height: 9.00 – 7.875 = 1.125. So the answer is that the piston compression height should be 1.125 inches.

That will put the top of the piston exactly at the top of the engine block, which is usually best for quench and performance. If you want the piston to be 0.010 above or below the deck, simply add or subtract that amount from the compression height. Easy.
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reliable source of info
Re: cc your cylinder heads

Nothing important to add but I get to use a pic of me CCing heads at the machine shop before I cut them. It's an old school shop so there's no fancy holder for the graduated cylinder but the results are the same.



Staff member
Re: cc your cylinder heads

BTW if anyone has a good source for those cc graduated cylinder's please post them, the place I bought the last one closed years ago
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Staff member
Re: cc your cylinder heads

I used Lab Depot. The first three burets are possiblities, after that they get pretty
expensive, the third one includes a stand to hold the buret. Don't forget you will need
something to refill the buret after checking. The top of the buret is going to be too high
and small to pour the fluid back into the buret, so some kind of squeeze bottle makes
refilling much easier. The 100cc models are approximately 775mm or 30 inches high.




Staff member
Re: cc your cylinder heads

thank you! that links shows those barrettes at not only way less, money, than I paid even 20 years ago but they appear to be a better quality
AND I'm going to need a new one , because one of my neighbors accidentally broke the old one moving stuff on a shelf where I had it stored next to dozens of oil filters, EVEN THOUGH it was inside a 3 foot long capped PVC 2" tube wrapped in bubble wrap... it was easily 20 plus years old and while not a huge financial loss its a P.I.T.A. because the place I bought it is no longer in bussiness ... 60020.aspx




grumpyvette said:
storing cams, you don,t want damaged
don,t forget to print out the CLEAR details of whats inside the tube, for later reference, and place it in a zip loc bag and tape it to the outside, because trust me in a few years if you have 4-8 stored you won,t remember exact details on each without reference materials




if your storing a cam, home depot sells 24" and 48" long sections of 2" PVC pipe, you buy that section of PVC pipe and matching diam, glue on cap for one end, and the rubber clamp band cap for the other, end store the sealed tube vertically where it won,t get knocked over with the glue cap end down the cam inserted and pour in a quart of cheap oil and cap the pvc, a cam stored vertically like that lasts for decades, I generally tip this long containers upside down for 15 seconds every few months when I remember too, to assure the cams stored are fully coated with oil , but I recently pulled out a cam stored like that since the early 1990s that looked perfect so the system works.

btw you can store welding rods (OBVIOUSLY DRY) and any other long object that benefits from protected storage (like seldom used precision instruments) that will fit in various diameter and length PVC tubes like this
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The Grumpy Grease Monkey mechanical engineer.
Staff member
several months ago I found out that the large capacity barrette that was very similar to this set up but held 150cc
that Id stupidly lent to a "friend" was returned busted , without him ever mentioning that little fact
upon looking into its replacement I find that the medical supply house I originally purchased mine from is no longer in business ,
and it seems that the 150cc burette is not a commonly available size

summit racing has a 250cc that would be a decent replacement
but the listed price of nearly $250 seems rather absurd
so money being rather tight Im looking for options and
would rather find an acrylic 150-250cc burette
IDEALLY PRICED AT under $100 if I can. any ideas gentlemen




if you've ever ported heads , lapped valve seats or CC ed heads you quickly found that you,ll need some type of cylinder head stand to position the heads and lock them in the exact location and angle you need to easily access the ports and combustion chambers to maintain the correct angle and if you bothered to shop around youll find the stands available are either pure crap, or far to expensive so you generally find you use sand bags or fabricate your own custom cylinder head holding stands once you get fed up with them moving while your working on the heads.






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The Grumpy Grease Monkey mechanical engineer.
Staff member
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Not again Grumpy ? !
I have never seen. Pyrex flat glass plates for CC Combustion Chambers .
Mine is Pexi glass plastic .


The Grumpy Grease Monkey mechanical engineer.
Staff member

Lexan Polycarbonate clear 1 sheet - 1/2" thick x 6 " x 6"


I found two 1/2" thick 6"x 6" thick lexan clear sheet on scam bay for about $22 plus shipping that will allow me to fabricate,
a step drill helps
by simply cutting into two equal pieces and drilling a counter sunk 3/16" hole in each half.
lexans a whole lot stronger than plexi-glass, and 6" x 6" allows more sealing surface options so thats the route I took
and its extra stiffness and weight helps seal the measuring fluids


250 cc burettes typically sell for $340, they can be found for under $200 if you shop carefully,
and a
250cc version is far easier to work with in my experience than your more common 100cc version

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The Grumpy Grease Monkey mechanical engineer.
Staff member
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