Small Block Cylinder Heads 'Stock Specs'

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69 cuda 440 said:
small block cylinder heads

cc's / port volume / size / flow

1966 - 1967 {273} casting #2658920

heart-shaped combustion chamber

factory cc level..........................62.0 to 65.5 cc's
recommended minimum cc's......57.3 cc's

intake port gasket size...............1.05" x 2.07"
exhaust port gasket size.............1.14" x 1.59"

intake valve................................1.78"
exhaust valve..............................1.50"

intake bowl size.........................1.53" {86% of valve}

intake port.................................125 cc
exhaust port...............................61 cc

intake flow...............................158 CFM @ .450" Lift.........160 CFM @ .500" Lift
exhaust flow............................107 CFM @ .450" Lift.........109 CFM @ .500" Lift

intake-to-exhaust flow.....................67.4%................................67.9%.............
Click to expand...
 
Jake,

I was only posting the results from 'Stock' and 'Unmolested Virgin Cylinder Heads'.

But, in the #2659820 Cylinder Head ~ 1.78" to 1.84" Intake Valve Flow comparison.

Stock Intake Port Volume..........125 CC

1.78" Intake Valve
1.53" Bowl Opening {86% of Valve}

Intake Flow.............158 CFM @ .450" Lift........160 CFM @ .500" Lift
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1.84" Intake Valve
1.60" Bowl Opening {87% of Valve}

Intake Flow............163 CFM @ .450" Lift.........167 CFM @ .500" Lift
 
69 Cuda 440 said:
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So what you're saying is,

That if you have '2' sets of 'identical' Cylinder Heads and pop them on the same
Small Block Mopar Engine, they will give the same 'exact' output without any variance + or -.

Who are you kidding..........
Click to expand...

You make my point for me, what hell good is this if every head were to give diff specs when tested. Seriously though...ive tested diff cores of the same casting, they were damn near identical, and I have yet to cc a 318 int port and get more than 125 cc unless its been worked, meanwhile the number actually gets smaller with valves jobs sinking the valve into the port!

One cc , let alone 2 cc's is a big diff in port size, thats like chopping the guide down 3/8 .
Almost none of our Mopar heads come with chambers of the actual cc listed in spec sheet from the factory or books, there would be motors with cyl pressures all over the place. The first set of heads that actually measured up to what a spec sheet stated were the 302 heads that actually are what they were advertised as, and I believe the magnums possibly...but I don't bother with those heads because putting work into them is like building houses in New Orleans, at anytime that can go bad...

My points are valid, I speak facts.
We dont agree on all of this.
How about you make a youtube vid showing how you come up with these numbers?
 
Mr. Wild & Crazy,

I agree, used Cylinder heads {cores} will undoubtedly come up with less
Intake Port Volume.

But we have measured a set of old 'new stock' #2843675 Cylinder Heads that
were from 1968, still boxed.

With 'untouched' Valve Seats and 'new' Mopar Intake Valves installed,

We came up with an average of 126.7 CC's {rounded off to 127 CC's}.
 
And I already stated the 675 heads I tested were off a 40k engine with the vj damn near perfect like new, they are the heads I used in the porting for the average Joe thread.
Now please go look at the pics of that vj and tell me its sunk to the tune
oof 2 cc's
Btw ...Anyone here have any new in the box 318 heads from 1971 they want to test and report back?
 
I've found the chamber cc volume off as much as 2cc on the same head. Very little of the info out there is accurate, because none of the castings are accurate.
 
Posted Result Information for 273 - 318 Cylinder Heads.

* Some report Intake Port CC Levels from {118 to 124}
* Others have come up with CC Levels {123 to 126}
* And some have it {125 CC 'dead nuts'}
 
Awesome that's greatly appreciated... I have found in my personal tests the combustion chamber volume is actually around 66cc on the #6671 castings and around 63cc in the #466 heads oddly enough
 
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