Indy BB head data

i'm going to post some of my findings for a few different Indy BB heads, with a few different levels of prep.
while i'm in no way claiming these are the last word in Indy head flow data, they will be able to be directly compared to each other since they are all off the same bench, with the same operator, on the same bore size.
when i'm done, maybe one of the mods can save it for future reference, since questions about these heads come up from time to time.


i'll start with the 440-1.
this is the latest version with the heart shaped chambers. the earlier ones with the "D" shaped chambers didnt flow as well in the mid-lifts unless a fair amount of chamber work was done.

all these tests were done on the same cylinder of the same head(#1).
4.375 bore, 28" test pressure, radius plate on intake, no flow tube on exhaust.


Intake ports;
A- OOTB, no valve job, zero porting
B- valve job and back cut valves only, zero porting
C- valve job, back cut valves, blend away ridge where casting meets bowl cut("bowl blend")
D- valve job, back cut valves, open bowl, minor trim of guide boss, relieve chamber adjacent to valve("bowl port"), minor touch up of short turn


lift----A----B----C----D
.100--67.2/ 74.3/ 74.3/ 77.4
.200-139.0/146.4/146.4/150.0
.300-205.4/206.1/208.6/213.5
.400-258.0/259.9/261.8/267.4
.500-297.3/299.2/308.5/314.1
.550-308.5/308.5/321.6/325.3
.600-299.2/299.2/319.7/334.7
.650-299.2/299.2/312.2/334.7
.700-306.6/308.5/317.9/342.2

Exhaust ports;
E- OOTB, zero porting
F- valve job, back cut valve only, zero porting
G- valve job, back cut valve, "bowl blend"
H- same as "G", relieve chamber adjacent to valve, no additional porting in bowl

lift----E----F----G----H
.100--55.9/ 61.3/ 62.1/ 63.0
.200-107.8/110.3/110.3/126.4
.300-146.3/148.8/148.8/162.4
.400-179.8/179.8/181.0/197.1
.500-211.4/209.5/209.5/220.9
.550-220.9/220.9/220.9/228.6
.600-228.6/228.6/230.5/236.2
.650-234.3/234.3/236.2/241.9
.700-240.0/240.0/242.6/245.7

IMO, if you dont at least prep the heads to the level of "D" and "H", you're not really going to take advantage of what these heads are about.

unfortunately, i dont have the equivilent test on an SR head, all on the same head/same port, in those small increments like on the 440-1.
but the numbers will still be representative of what you could expect for the various levels of prep.

440-SR head: 4.375 bore, 28" test pressure, radius plate on intake, no flow tube on exhaust.

Intake ports;
A- OOTB std port, zero porting
B- OOTB CNC Maxx port. this is an option from Indy where they CNC the intake opening to MW size, along with doing a CNC bowl blend. no additional porting or valve seat work.
C- this is how i like to prep these heads, so you get the benefit of stepping up from a stock head or RPM type head.
this particular port started out as the CNC Maxx job, then got the chambers ported, my valve job, back cut valves, "bowl ported", guides streamlined, short turns reworked.

lift----A----B----C
.100--70.7/ 71.9/ 74.7
.200-134.2/131.7/147.6
.300-195.2/189.1/212.0
.400-238.2/239.3/265.1
.500-263.6/284.9/305.1
.550-275.6/302.9/319.7
.600-279.3/286.1/329.4
.650-280.3/286.8/336.6
.700-282.3/286.1/343.3

Exhaust ports;

D- OOTB std head, zero porting
E- OOTB Maxx head, CNC bowl blend
F- Maxx head, PRH valve job, back cut, mild full port and polish. this is how i like to do these to match the intake port in column "C".

lift----D----E----F
.100--56.5/ 54.7/ 56.9
.200-104.1/ 95.4/131.4
.300-142.6/131.4/157.2
.400-171.1/159.9/197.1
.500-195.9/182.9/225.9
.550-203.3/192.4/236.2
.600-209.5/200.7/245.3
.650-214.5/205.7/253.3
.700-218.2/210.3/255.6

SR heads ported to the level of "C" and "F" are a good choice for 434-511" motors up to about 750hp. beyond that power level(or bigger displacement), 440-1's should be more cost effective.

ive sold quite a few sets of the various versions of EZ heads over the last couple of years.
but.....for the most part, it usually boils down to....std port window, or MW port window.
the EZ intake port responds better to opening it up to MW size better than any other head ive seen.
its a fantastic gain for the amount of work involved.

while i am a fan of these heads, i dont feel they will be putting their best foot forward if you use either the EZ or EZ-1 without doing any porting at all.
there is a noticable ridge around the seats that shrouds the valves in the lower and mid lifts.

i get asked quite often if the std port version is worth the extra $$$ over an RPM head. as with most things engine related....."it depends".
it depends on the engine/car combo, and whether or not some additional $$$ can be aloted for some prep work.
the milder the combo, the less gain you'll see. and if the cam isnt solidly over .500 lift, and you dont elect to have some prep work done, you may be a bit disappointed.

440-EZ heads- 4.375 bore, 28" test pressure, radius plate on intake, no flow tube on exhaust.

intake ports;
A- OOTB std port, zero porting
B- open to MW size only, no valve job, no additional porting
C- MW size, PRH valve job, back cut valve, ported chambers, "bowl port", narrow guide boss, tweek short turn

test A and B are the same port/same head. test C is a different head. the A/B head didnt end up getting ported as much as the C head.

lift----A----B----C
.100--72.5/ 73.1/ 71.4
.200-126.8/129.3/144.6
.300-183.0/187.8/208.9
.400-228.8/239.3/261.4
.500-269.2/291.7/307.0
.550-283.1/312.2/321.2
.600-287.9/321.6/330.9
.650-293.5/331.7/341.0
.700-299.2/340.3/351.1

ive got some numbers at the shop for some std port EZ's with the valve and seat work done, along with a "bowl blend", which i'll post tomorrow.
i dont really feel its cost effective to try and "port" these heads if left with the std port opening, since the real problem is actually the opening. the transition from the std opening to the roof is pretty abrupt, and is where the problem is. if you needed to keep the std port window, you could actually fill the area in the roof and pick up flow.
you could also use some of those Hughes intake gaskets that allow you to raise the upper part of the port opening as much as your intake would allow. the more of that ridge you eliminate, the closer you'll get to the flow you get with the MW window.

exhaust ports;

D- OOTB zero porting
E- basic full port and polish, PRH valve job, back cut valve. these ports are small and easy to port. once you do anything beyond a bowl blend on the intake side, just go this far(or father) on the exhaust. compared to how well the intake ports work.....this is the weak side of these heads.
i'll have some "bowl blend" numbers tomorrow.

lift----D----E
.100--52.3/ 56.6
.200- 94.2/105.6
.300-130.2/143.3
.400-164.1/178.5
.500-190.9/208.3
.550-203.3/219.0
.600-210.8/233.5
.650-216.2/238.5
.700-220.7/242.6

i will add this about the exhaust ports. all these heads come with the bowls CNC'd.
on the exhaust, the way that CNC blending meets the valve job on the side away from the exhaust port exit has a noticable impact on how good they will end up being when finished.
if the CNC job comes right up to the bottom of the 45 seat angle, they generally wont be as good as the ones that have more material there for a proper blend. its not a big difference.....but its a few cfm for sure.

good info...

EZFTW

any chance you'll be doing the different levels of -1 cnc heads? in the not so distant future i want to buy a set of bare cnc'd -1's. this info is what i'm looking for at present.

Thanks Dwayne. My EZ's are right there at your readings on my sheet you sent me. I have 329.5 on the intake at .600 and you have 330.9 posted. I call that very good work. Thanks again for the fantastic work you did on my heads. Ron

Great info,Dwayne!! Thank you! This may make the tech archive for future reference for all to see!

Quote:

---

SR Head
B- OOTB CNC Maxx port. this is an option from Indy where they CNC the intake opening to MW size, along with doing a CNC bowl blend. no additional porting or valve seat work.
lift----A----B----C
.100--70.7/ 71.9/ 74.7
.200-134.2/131.7/147.6
.300-195.2/189.1/212.0
.400-238.2/239.3/265.1
.500-263.6/284.9/305.1
.550-275.6/302.9/319.7
.600-279.3/286.1/329.4
.650-280.3/286.8/336.6
.700-282.3/286.1/343.3

---

I am shocked at the low flow for the Indy CNC program. Is that what you get for the ~$1000 CNC? Or is that a differnt CNC option?