X head - cc's

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512Stroker

512Stroker

We are all here because we are not all there.
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What is the combustion chamber volume of a factory stock X head?
no mod's, 1969
 
around 52 I believe. I picked up a pair with some work done very cheap. Took it to shop that did the work and he said something about 52
 
It varies. If you want an absolute answer, it's best to measure. I've seen as little as 67 and as large as a tick over 72. I think most are "around" 68.
 
Louie70Dart said:
around 52 I believe. I picked up a pair with some work done very cheap. Took it to shop that did the work and he said something about 52
Click to expand...

They're nowhere near that small. The X head is an open chamber head "pretty much" like all the rest.
 
end to end can vary on the same head
especially if they have had unknown work in the past
gotta check
always more uncut than the FSM says
 
That happens too and usually are different
after you get the head square then you have to open up a few chambers or all of them (if legal) if you want to be dead nuts on
no need to mention opening up the bowls DYI if the heads are off -makes a big difference especially if proceeded by a nice multi-angle valve job
that's why I mentioned flow cutting (or at least leveling out) turbulence with totally stock heads at sub .500 lifts even
me I'd go - (but good) now if going to better heads later where i would go custom for sure once I had my flows
 
Wyrmrider said:
That happens too and usually are different
after you get the head square then you have to open up a few chambers or all of them (if legal) if you want to be dead nuts on
no need to mention opening up the bowls DYI if the heads are off -makes a big difference especially if proceeded by a nice multi-angle valve job
that's why I mentioned flow cutting (or at least leveling out) turbulence with totally stock heads at sub .500 lifts even
me I'd go - (but good) now if going to better heads later where i would go custom for sure once I had my flows
Click to expand...
Set of 915 J , one was 64 while the others were 69.something -70cc Ground it some after scribing and opening the chambers to the bore size. They all needed a little touch up after the scribing to dial them perfect.
 
do not scribe out to the gasket size the air does not like to hit the sharp edge of the top of the bore
of course you can chamfer the top of the bore but why unless you have a flowbench
ex is not as critical unless valve hits the top of the block
 
I measured my '69 X heads at 75 cc's.

I had them milled down to 68 cc's. (forget how much milled)

I was at a performance clinic put on by Herb McCandless and he even said the X heads were more like 75 cc's and he had never seen a set at the advertised volume of 63 cc's.
 
Wyrmrider said:
do not scribe out to the gasket size the air does not like to hit the sharp edge of the top of the bore
of course you can chamfer the top of the bore but why unless you have a flowbench
ex is not as critical unless valve hits the top of the block
Click to expand...

lol
 
To much variance, mine have had just a clean up cut to the surface which brought them to 65cc IIRC. You just need to measure them.
 
Wyrmrider said:
do not scribe out to the gasket size the air does not like to hit the sharp edge of the top of the bore
of course you can chamfer the top of the bore but why unless you have a flowbench
ex is not as critical unless valve hits the top of the block
Click to expand...
No one is scribing the gasket. What I'm talking about is marking the heads left and right ,assigning them to each Bank permanently. Put both the heads on w/bolts in to snug them up...flip it on the stand and scribe using the cylinder.

The fire ring of the gasket is larger than the bore...that would be a disaster.
 
way to do it MO
I've had heads brought in opened up to the gasket- it is a disaster
and as yo say mark left and right and get dowels (and head) in the right place

That said I'll use a small bore steel shim gasket and scribe around the valve pockets
did it lots with the stainless 361-413 truck gasket on 440's
I think I did it with SBM also
hard to find those gaskets now
 
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