If I'm selling new Indy heads, and the customer is looking for something that's "fully ported", I just get them CNC'd from Indy, then I do my valve job and prep.
On my bench, after the VJ and prep, a 440-1 CNC 325 flows 360-365.
A CNC 345 goes 380-385.
How do these numbers compare to a hand port job? Just wondering if CNC is set for a conservative number as opposed to having someone hand port and get a visual of the actual ports before and after.
I've never seen anything "magical" with these heads...... Meaning flowing more than they "should" for what's been done to them.
Without trying to reengineer what's there...... After you've put a good valve job in them, and blended that into the bowls and chambers...... You pretty much have what you have.
If you want more, it's a matter of just upsizing the entire port(for the most part).
So, to answer the question about what hand ported versions flow..... It usually depends on how much time someone was willing to stand there and make them bigger.
I will add that the intake short turn on the CNC 345 seems to have more height than even an ootb unported 440-1........ So I don't know that you can put that exact same port into a std
440-1.
I don't feel the Indy 345 program is that conservative. It's a pretty spacious port, and the ex ports are pretty big as well.
Myself, I don't like standing there and just hogging chips out of a head to make it "big", so when I port these they are probably more in the 320cc range, and as a result don't flow as much as the CNC versions, which are bigger. I get 350-355 with a 2.19 valve, 355-360 with a 2.25 valve.
Truly "ootb" 440-1's....... Meaning NO porting or blending, barely go over 300cfm.
But with a nice valve job and bowl blend, along with some chamber work, 340-ish is easy to get.
The newest version comes with the chambers CNC'd already, and those are a few cfm better with that first stage of prep.
After that....... You're def at the point of diminishing returns when it comes to the amount of time porting vs the gain in cfm.
Here are some numbers from a new set with the cnc chambers, just as they came ootb, Indy 2.19 valve and valve job. Zero porting.
Lift------ int
.100---70.2
.200--146.8
.300--216.4
.400--271.1
.500--304.8
.600--297.3
.700--310.4
That dip around .600 lift can a little tough to get rid of.
I guess I should clarify the size thing......
Making them bigger doesn't guarantee you'll get big numbers out of them.
The other side of the coin is.......if you keep them on the small side, you're only going to get so much out of that too.
