Here we go, bought a set of 440 Source Super Stealth Heads.

[heyoldguy]

Been a lot of curiosity about the Super Stealth heads and a real lack of information. So, we'll have a pair early next week to test. The last test port we did on the standard Stealth head went,

..................OOTB..................ported

.100"............73 cfm................80 cfm
.200"...........151....................163
.300"...........214....................220
.400"...........245....................263
.450"....................................285
.500"...........262....................301
.550"....................................313
.600"...........276....................329
.650"....................................339
.700"...........281....................341
.750"....................................343

We've even got 350 cfm @ .700" lift and 354 cfm @ .750" lift from the standard Stealth. Can the Super Stealth really do better? We're gonna find out.

[tan top]

 

 

[Brightyellow69rtse]

definatly interested in this 

[cdr]

well we already know gonna have to go new seats & bigger valves ,i stopped on mine cause i dont need anymore flow !




been a while,been pretty ill,but the weather has cooled of some & finally got my flow bench & heads to the house,so i got some #s together so far,
these are the 440 super stealth & this is for a street motor,my testing cyl adapter is 4.250 bore diameter, i will machine it to 4.4 when i can get to it.

otb .200 140              short side work,& raise port window to max wedge      .200 160
     .300 202              2.14 valve,30 deg back cut,NO SEAT work done yet    .300 220
     .400 242                                                                                       .400 260
     .500 256                                                                                       .500 287
     .600 267                                                                                       .600 307
     .700 267                                                                                       .700 323
                                                                                                        .800 334

OK opened the seat up a little & did a little combustion chamber work,i am stopping here cause i dont need more flow,this is a street engine build,@ .700 they flow enough to make 688 hp,my cam will be  .650 lift. these heads really want a bigger valve but to do that the seats would have to be changed,flowing the head with no valve they flow 360 not saying they would flow that # with a bigger valve but the would definitely pick up some.

.200 164
.300 217
.400 264
.500 290
.600 314
.700 335
.800 345

i think heyoldguy will make these heads ROCK !!!!

[heyoldguy]

I really appreciate that you posted your flows back when you did, 'cause your's are the only ones we have any information on.

The fact that your's are still going up at .800" lift gives me hope that there is bunch more that can be had down lower with the larger valve.

[heyoldguy]

cdr,

Did your Super Stealths come with what looks like weld repair to the aluminum, inside the ports, underneath the valve seat inserts and the spring pockets?

First flow tests.

Lift............OOTB............1st porting

.100...........72/61..............80/65
.200.........147/124...........160/139
.300.........208/161...........228/184
.400.........250/190...........279/216
.500.........276/207...........315/246
.600.........280/217...........324/259
.700.........280/224...........335/275

I need some aluminum put back inside the ports. On this set, the bowls are too big for the seats on both the intake and exhaust. No way to fix them without epoxy in the intake and welding the exhaust. They look like the factory FE Ford bowls, phew.

[cdr]

under the seats yes,, spring pockets no



charlie

[cdr]

strange ,,,yours flow ootb way more than mine did 

charlie

[mopar0166]

Did you use thier rocker set as well?

[heyoldguy]

Did you use thier rocker set as well?

I'm using the 440 Source rockers on my grandson's pick-up truck, but I won't be using them on any high performance engines, and I will now go to higher end (more expensive) rockers for anything else I build.

[heyoldguy]

Last test tonight and probably for awhile.

Lift.............S/Stealth........Indy 325cc CNC 440-1

.100.............74 cfm................66 cfm
.200............153....................141
.300............216....................212
.400............267....................268
.500............309....................311
.550............329
.600............344....................348
.650............344
.700............352....................356

[cdr]

heyoldguy what size valve is that with?
thanx charlie

[metalstorm440]

I should do some reading to see what you are working with but will ask this,Are you going with a std port opening or MW?This should be some good reading so thanks for posting the topic.

[heyoldguy]

As this is certainly not turning out to be a race head, I thought we'd see what could be done without too much effort. As cdr said, you do need a bigger valve to make the head work. But what can be done with just the Stealth 2.14 valve and not fool around in the bowl next to the guide?

I have three tables for what would be the #7 or #2 combustion chamber.

A fourth (4) table for another port with a 2.25" intake valve and more serious porting.

The first (1) is the flow in the intake port with a stock Stealth 2.14" intake. OOTB the port window is a really erratic shape and slightly larger than a standard port opening.

The second (2) is the same port with the valve backcut, the bowl blended into the underside of the seat (this cannot be done properly because the darn bowl is so big as compared to the hardened seat), the short turn layed back under the seat, the 440 Source stock valve w/ backcut. and a 5 angle valve job. No combustion chamber work was done.

The third (3) is the same as (2) but with the port window opened to max wedge size.

Lift..........(1)...........(2)...........(3).............(4)

.100........73............73............73..............75
.200.......146..........146...........145............155
.300.......205..........205...........208............218
.400.......247..........254...........257............264
.500.......271..........283...........295............313
.600.......271..........295...........316............344
.700.......274..........295...........327............354

There is the possibilty that the port can go over 360 cfm @ .700", because, we backed up a few times by making incorrect adjustments and lost some flow, and then gained it back by continuing on. If we go back over the notes and just make the positive adjustments to the port shape, we could perhaps get greater flows.

We can also make some changes and increase the flows in the .100"-.400" range by as much as 10 cfm each and lose some top end flows.

If you want cheap and are willing to invest in a diegrinder and some burrs, you can get 330 cfm or so at .700". I won't be doing much with the S/Stealth head, with the same amount of work, other heads can be made to flow 375-400 cfm instead of 350 cfm. If you want a race head, buy one........but this ain't it.

[cdr]

thanx for the info heyoldguy

[heyoldguy]

thanx for the info heyoldguy

You are welcome. And don't think I'm down on 440 Source. I've always received excellent customer service from them. I wonder what will happen now that I've sorta panned their cylinder head.

[tan top]

this is interesting  stuff , thanks for posting this info 

[oldschool]

they perform better than i thought they would. thanks for sharing