Stage IV update!!!!!!

Posted by: R/T1968R/T

Stage IV update!!!!!! - 12/02/17 06:16 PM

Have a set of Stage IV heads that are milled .080. If i use the 452 chamber size it looks like they could be 75-76 ccs? .080 divided by .0062 for every cc = 12.9 ccs
Posted by: Cab_Burge

Re: 452 Cylinder head chamber similar to stage IV ? - 12/02/17 06:31 PM

Stock 452 heads check above 90 CC, at least all of the ones I have checked did shruggy
I think the stock uncut Stage Four heads where large like that also, maybe 84.0 CC to start with, maybe not confused
Posted by: LaRoy Engines

Re: 452 Cylinder head chamber similar to stage IV ? - 12/03/17 07:49 AM

When we are putting together our bazillion dollar engines, why don't we just measure these things to know for sure, instead of guessing?
Posted by: fast68plymouth

Re: 452 Cylinder head chamber similar to stage IV ? - 12/03/17 01:28 PM

The brand and size of the valves, how the valve job was done, how many valve jobs have been done, how big they actually were to start with, and how much they've been milled are all factors in what size the chambers are.

If you really want to know...... You have to measure them.
Posted by: BSB67

Re: 452 Cylinder head chamber similar to stage IV ? - 12/03/17 04:58 PM

Originally Posted By LaRoy Engines
.......why don't we just measure these things to know for sure, instead of guessing?


Hmmm.
Posted by: R/T1968R/T

Re: 452 Cylinder head chamber similar to stage IV ? - 12/03/17 05:43 PM

Youre right I shouldnt guess. I have the plexiglass already just ordered a graduated cylinder.
Posted by: dogdays

Re: 452 Cylinder head chamber similar to stage IV ? - 12/04/17 01:03 PM

Have the intake faces been milled as well? With 0.080 taken off this needs to be done.
R.
Posted by: R/T1968R/T

Re: 452 Cylinder head chamber similar to stage IV ? - 12/04/17 06:18 PM

Intake faces where milled accordingly. Manley stainless valves 2.14 In 1.84 ex, ported and polished. These heads were on a mild 440 that went 10.77 in a full interior 69 Charger. I know they flow good, just want to work out a good compression for a street car.
Posted by: yella71

Re: 452 Cylinder head chamber similar to stage IV ? - 12/04/17 06:58 PM

the only way to have the exact number is to cc them....that being said I had a set of those heads new right outta the box years ago and did not measure them but having seen many many bb mopar heads I will say they started out the same as any 452 head...BIG theres a reason they were cut .080 thou...
Posted by: R/T1968R/T

Stage IV update!!!!!! - 12/05/17 08:08 PM

So, I ccd the heads, Four different cylinders and all very close results. 67ccs!!!!! The math doesnt add up though. .080 milled should not come out this low. Take a look.
[img:center]http://imgbox.com/TzlEWqWG[/img]
[img:center]http://imgbox.com/hGtzAPsO[/img]
[img:center]http://imgbox.com/SKDI7MWj[/img]
[img:center]http://imgbox.com/Bkjkr5Tx[/img]
Posted by: fast68plymouth

Re: Stage IV update!!!!!! - 12/06/17 11:07 AM

The chamber diameter is roughly 4.250........ At .080 that works out to about 18.6cc worth of milling.

Installing larger valves, along with using valves with flatter heads reduces chamber volume.

67 + 18.6 = 85.6cc.

I can see that as a starting point with oversized aftermarket valves.

The outer row of head bolt bosses are a nominal 1.00" thick, stock.
If you measure a few it should give you an idea how close to that .080" has been cut off the decks.

This is why you measure instead of assume.
They are what they are.
Posted by: lewtot184

Re: Stage IV update!!!!!! - 12/06/17 03:01 PM

I get 19cc for the .080" mill. my stage V's were right at 88cc new. same chamber as stage IV's.
Posted by: Cab_Burge

Re: Stage IV update!!!!!! - 12/06/17 06:10 PM

Polishing the chambers make them bigger than stock work
Cutting the heads makes the combustion chambers smaller shruggy
As far as your reading on that digital micrometer are you putting any pressure on the gauge to make it tight up against the head? If so ,don't tsk
Do you have a decent regular, non digital, outside micrometer that you can set the calibration on? If so compare your readings between the two gauges and let us know what you find scope thumbs
If not don't worry about that now, you already know the CC up
I have seen as much as 4.2 CC differences in stock wedge and hemi heads between all four chambers on those heads shock shruggy
Posted by: dogdays

Re: Stage IV update!!!!!! - 12/07/17 07:37 PM

Regardless of what you should have, 67cc is what you've got. It makes no sense to worry about what you've measured or why it is that number. It is what it is.
on a .030 over 440 with Sixpack pistons and a 12cc head gasket you're looking at 10.9:1 compression. That's high for pump gas.

R.
Posted by: R/T1968R/T

Re: Stage IV update!!!!!! - 12/07/17 09:00 PM

I think with out any quench Im screwed. I can always put them on a smog motor or a motor with L2266 which are .090 in the hole.
Posted by: lewtot184

Re: Stage IV update!!!!!! - 12/08/17 09:41 AM

Originally Posted By R/T1968R/T
I think with out any quench Im screwed. I can always put them on a smog motor or a motor with L2266 which are .090 in the hole.
there are quench dome pistons.
Posted by: JohnRR

Re: Stage IV update!!!!!! - 12/08/17 10:51 AM

Originally Posted By R/T1968R/T
I think with out any quench Im screwed. I can always put them on a smog motor or a motor with L2266 which are .090 in the hole.


How deep are the open part of the chambers now? You can get a piston made that will give you quench and a streetable compression, I had Diamond make me some a few years ago.

Sorry for the crappy picture, it's a D shaped dome with a D shaped dish, 9.5 compression 440 , though your heads being as small as there are might be a challenge on the dish size ?
Posted by: lewtot184

Re: Stage IV update!!!!!! - 12/08/17 01:27 PM

a kb184 with a .060" head gasket may be a perfect fit.