Jim L - Are you still using a SF-110 (like myself) and having to throw big correction factors into the results (again, like myself), or have you upgraded flow benches since the last time I asked about your equipment?

When I see BIG starting numbers like this it raises LOTS of questions about flow bench calibrations.

.100...............73...........................73
.200..............151..........................152
.300..............214..........................218
.400..............245..........................267
.500..............262..........................308
.600..............276..........................337
.700..............281..........................346


I have had a lot of Stealth heads on my bench and when I test I test EVERY port on every head. The most I have ever seen was 267cfm. Start with high numbers end with high numbers and those in the know, know better.

This! ^^^

I look at it this way: I see 9 out of 10 very good head porters have results within 10 cfm of each other. Then I see one guy with results that are nearly double that of the other guys. Who is the outlier? Or, am I to believe that Dwayne and the other head guys here are a bunch of know-nothing hacks?

I had Jeff's/MCH Eddy's checked on a local bench and the numbers were within 1 cfm of each other. Trust, but always verify.

This! ^^^

I look at it this way: I see 9 out of 10 very good head porters have results within 10 cfm of each other. Then I see one guy with results that are nearly double that of the other guys. Who is the outlier? Or, am I to believe that Dwayne and the other head guys here are a bunch of know-nothing hacks?

I had Jeff's/MCH Eddy's checked on a local bench and the numbers were within 1 cfm of each other. Trust, but always verify.

Wow, I've been missing out on all the fun..........

2" tube on the exhaust.......28"..........

Lift.............Stock 906..........906 Ported

.100................66/54................89/60
.200.............131/103............161/129
.300.............189/145............212/185
.400.............222/168............257/216
.500.............234/176............297/234
.600.............237/183............331/253
.700......................................347/264

These 906 heads were on our 500" engine when Comp Cams forgot to turn the water on to the engine. It got so hot that the paint was burning off the cylinder heads and all the exhaust valves seized to and pulled the bronze guides out of the heads. The valves were then pounded out of the guides, the guides knurled on the outside and pounded back into the heads, reamed and the valves stuffed back in. With 15 bent valves and 11-56% leakdown it then made 730 HP on 93 octane pump gas. Oh yeah, the heads never cracked and still don't leak water.

Lift......Best OOTB Stealth ever tested.......Fully ported

.100...............73...........................73
.200..............151..........................152
.300..............214..........................218
.400..............245..........................267
.500..............262..........................308
.600..............276..........................337
.700..............281..........................346

With the 2" pipe the Stealth exhaust ports will approach 300 cfm when ported.

Same oh, same oh. Too bad I'm not wealthy. Just staying alive.

I figured I'd throw in these numbers too....
452 heads with 2.14/1.81 valves, done by a well known mopar
volume head rebuilder, no porting, no blending. To the best
of my recollection, these are the worst flowing big valve heads
I've come across. They had a big "bowl hog" type cut done under
the valve job that really hurt the flow. IIRC, these flowed less than a
completely stock head with the OE valves and valve job.

Lift------in/ex
.100----67/52
.200---118/97
.300---169/129
.400---196/141
.500---217/145
.600---222/145

I spoke with my customer the day other on this set of Stealths I have in the shop. From our original conversation I had assumed he was only looking for the "bowl blend" level of porting done to these heads. After our conversation the other day he indicated he was more interested in having them flow solidly in the 280's+, so I went in and opened the pinch to 1.140 and trimmed the guide boss and the port roof adjacent to the boss. This is the same port as the other two tests from earlier(#1).

Lift------intake flow
.100----71
.200---146
.300---211
.400---254
.500---277
.600---285
.700---290

Here are some intake port volumes to give an idea of how much work is involved to get from one level to the next. I didn't check the OOTB port volume, but the bowl blend only removes a couple of CC's worth of material.

Recut seats, blend bowls = 210cc
Open pinch to 1.140, narrow guide boss = 217cc
MCH full CNC ported and valve job = 252cc

On an Edelbrock head, if you do a basic port and polish it'll flow right at about 300cfm, and those ports are usually in the 228-230cc range.