906, Edelbrock RPM, Standard Stealth

[heyoldguy]

It's been an interesting two weeks on the flow bench.

We have been wondering just what you could get out of the 906, Stealth and RPM with the standard stock port window. Turns out they all seem to be capable of about the same peak flows @ .700" lift. RPM 335 cfm, Stealth 337 cfm & 906 338 cfm. By raising the port opening in another port, the flows went to 346 cfm with the Stealth and 350 cfm with the RPM. Haven't put the 906 to the bigger port test in this session.

It doesn't make sense to push these heads to those flows when other heads can do the same or better with less work, but it was fun experimenting just to see what they could possibly do.

Strange to think of it though, you could buy a pair of Stealth heads, spent the money for valves and porting, and have a head that flows as good as a ported B1 BS, for less money.

[Ghoste]

That is interesting.  Are you planning to take the 906 to that next test with the bigger port?

[heyoldguy]

Not with the 906 heads being used in this session. Previously they have gone 339-342 cfm @ .700" and only once to 349 cfm.

[Ghoste]

And flow for them is well documented anyway I suppose.  The realy interesting thing is your point about the Stealth and the B1 BS.

[tan top]

  couple of years ago was about to get a pair of stealths ,

would rather iron  over aluminum heads ,   but just thinking spending big money getting them worked with all the tricks  ,   flowed .  on a 40 plus year old part  , that it is not uncomon for them to crack even when stock , factor in grinding on the ports etcetc , what might happen after a few hundred heat cycles   

saying this would love to get a pair of muscle motors 906 CNC  heads !! that can support over 600 horse

[heyoldguy]

  couple of years ago was about to get a pair of stealths ,

would rather iron  over aluminum heads ,   but just thinking spending big money getting them worked with all the tricks  ,   flowed .  on a 40 plus year old part  , that it is not uncomon for them to crack even when stock , factor in grinding on the ports etcetc , what might happen after a few hundred heat cycles   

saying this would love to get a pair of muscle motors 906 CNC  heads !! that can support over 600 horse

Well, I know what happens to our 906 heads when Comp Cams forgets to turn the water on to the engine before the dyno test. We repair the guides, put the scrapped engine back together and make 730 HP.

[tan top]

 couple of years ago was about to get a pair of stealths ,

would rather iron  over aluminum heads ,   but just thinking spending big money getting them worked with all the tricks  ,   flowed .  on a 40 plus year old part  , that it is not uncomon for them to crack even when stock , factor in grinding on the ports etcetc , what might happen after a few hundred heat cycles    

saying this would love to get a pair of muscle motors 906 CNC  heads !! that can support over 600 horse

Well, I know what happens to our 906 heads when Comp Cams forgets to turn the water on to the engine before the dyno test. We repair the guides, put the scrapped engine back together and make 730 HP.

yeah i remember reading about what happened there  ,  was it as much as that i forget , 730 , thats real good numbers

http://musclemotorsracing.com/muscle-mike-blog.html

[Chryco Psycho]

That would make sense then , I ported a set of 452 heads & we swapped to the Eddy RPM heads also ported & gained 3 hp

[heyoldguy]

Yep, if you put 2.14/1.81 valves in a 452 head you can beat the pants off a mildly ported RPM Performer head.

[Budnicks]

Thanks HeyOldGuy, great info...

[heyoldguy]

Yep, if you put 2.14/1.81 valves in a 452 head you can beat the pants off a mildly ported RPM Performer head.

Oh,oh. I forgot to say that you also need to port them 452 heads along with installing the valves.

[Chryco Psycho]

It does seem to help doing some port work on the Iron heads 

[firefighter3931]

Any "before" vs after flow numbers ? Just curious what an untouched port flows on your bench 



Ron

[cdr]

heyoldguy,very good #s,would like to see what you could get out of the super stealth heads,i havent had time to get back to work on mine but will let you know  thanx charlie keel

[heyoldguy]

Any "before" vs after flow numbers ? Just curious what an untouched port flows on your bench 



Ron

No problem. It'll be later tonight, I'm just on a quick break.

[heyoldguy]

Ah, to answer stock flows of the Stealth and the RPM heads with comparisons to ported heads. I figured as long as we were doing this comparison I'd kick it as high as I could. I'm now all out of ports to work in my test heads.

First the Stealth

............Stock......Past Ported.......Today

.100".......67............73...............71
.200"......142...........149.............153
.300"......205...........214.............217
.400"......240...........256.............265
.500"......255...........288.............301
.550"........................................325
.600"......267...........304.............331
.650"........................................339
.700"......268...........322.............344
.750"........................................348


And then Edelbrock RPM

............Stock.........Stock.........Past ported..........Today

.100"........70.............71...................73..................75
.200".......143...........155..................148................152
.300".......201...........205..................213................216
.400".......243...........252..................258................265
.500".......271...........275..................289................301
.550"..................................................................322
.600".......285...........286..................305................333
.650"..................................................................343
.700".......293...........287..................321................350
.750"..................................................................354

I sacrificed some lower lift flows today, just to see how high I could push it in the .550"-.750" lift range.

[tan top]

    stealth real good at 550  & 600 lift   not going too radical with cam lift

[Budnicks]

Thanks HeyOldGuy that's allot of work.... I appreciate it, great comparison...

[Musicman]

Good work brother

There's nothing more valuable than quality information... Especially when it comes in the form of a good old fashioned Side by Side comparison.

[Challenger340]

Good for you Oldguy  ....and thx for sharing the comparisons, interesting stuff.

From my memories back in the day, it takes an awefull lotta work...and TIME... to get iron stuff up around 330-340 on any Bench !
Thats as far as we ever got without pokin holes !

[heyoldguy]

Yeah, my favorite place to install holes is in the water jacket, between the intake bowls, just by the head bolt hole. Or in the heel of the bowl between the valve guide and the seat.

[Budnicks]

Challenger340 those are some damn perty looking cast iron heads, intake ports there...

[Musicman]

Farg'n magnificent 

[firefighter3931]

Any "before" vs after flow numbers ? Just curious what an untouched port flows on your bench 



Ron

No problem. It'll be later tonight, I'm just on a quick break.

Thanks for posting the comparisons....outstanding results ! 



Ron

[ChargerST]

Those are some decent numbers! is there a reason anymore for choosing RPMs over Stealths when you're gonna get them ported anyways?
So do you offer porting work or was this just for fun?

[heyoldguy]

I see no reason to buy Edelbrock over Stealth if you are going to have them ported. But flows in the 335-350cfm range are expensive, though they don't require any welding, they do need seats replaced and new valves. Yes, we do porting work, but it is fun.

[ChargerST]

What's a ballpark price for head porting to get a 330cfm flow on Stealths or RPMs? I heard that RPMs are less prone to cracks as there is more material compared to Stealths. Stealth design is basically a 915 in aluminum - what might have worked for a cast iron head must not necessarily work in aluminum in respect to strengh.
what's your take on that issue?

[heyoldguy]

What's a ballpark price for head porting to get a 330cfm flow on Stealths or RPMs? I heard that RPMs are less prone to cracks as there is more material compared to Stealths. Stealth design is basically a 915 in aluminum - what might have worked for a cast iron head must not necessarily work in aluminum in respect to strengh.
what's your take on that issue?

My take? Whoever thinks that the Stealth is basically a 915 in aluminum is smoking some really good dope! The Stealth is NOTHING like the 915, thank goodness. I found the Stealth casting to be every bit as thick as the Edelbrock in every place I have tested them.

The porting for RPM or Stealth heads that flow 330 cfm would be $1600 and would include new Manley intake valves.

[ChargerST]

Good to hear that about the Stealth heads! Super Stealths seem to be a bit different though - just look at the wall thickness next to the pushrod hole:

[heyoldguy]

Looks like it is plenty strong enough to me to hold full manifold vacuum on closed throttle deceleration. That would be most stress it would be placed under as that area of the port would need no grinding attention. The fuel and air certainly aren't going to wear it out as they pass by. The material thickness in that spot really presents no problem. In one of my personal heads I have an emergency repair with JB Weld and Mountain Dew pop can in that area. Its never failed me.

[MSRacing89]

I have had the Stealths on my car for over a year now.  First we looked them over and added 10º Locks and retainers because we are running a mid .500" lift cam.  We run 1.5 Crane Gold rockers arms in combination with 3/8" pushrods and on the intake rod they rub so bad we had to take a lot of material off to make it work.  In the end, just to be safe, we went with hardened Smith Bros. 5/16 rods.  At that time we double checked all the guides and all the exhausts needed to be replaced and most intakes.

I really like the heads as we run them hard and make good power.  There are just some questions that need to be asked of 440 Source, as to why they keep producing the heads knowing that the aftermarket Rockers with 3/8" rods cause the need for major mods to the head?  Why not just clearance them in the casting process?  Not to mention they sell 3/8" rods on their site to work with these heads.  I called them and they said there could be "core shift in the block".....BS.  Fix the issue 440 Source as 98% of us run aftermarket Rocker arms.

[heyoldguy]

You make a very good point. On the Stealth head I tested, with every 1.6 rocker I used, and I used four different manufactures, the pushrod would rub on the intake port wall. The only time the pushrod cleared was when I used a 1.5 ratio rocker, and then it just barely cleared.

[Musicman]

Same here... I had to clearance mine for the 1.6, but I knew that going into it. My heads are also from the "very first run"...  I know a number changes have been made since then, but not in this area to my knowledge.

[cdr]

Looks like it is plenty strong enough to me to hold full manifold vacuum on closed throttle deceleration. That would be most stress it would be placed under as that area of the port would need no grinding attention. The fuel and air certainly aren't going to wear it out as they pass by. The material thickness in that spot really presents no problem. In one of my personal heads I have an emergency repair with JB Weld and Mountain Dew pop can in that area. Its never failed me.

well said

[Mick70RR]

I have had the Stealths on my car for over a year now.  First we looked them over and added 10º Locks and retainers because we are running a mid .500" lift cam.  We run 1.5 Crane Gold rockers arms in combination with 3/8" pushrods and on the intake rod they rub so bad we had to take a lot of material off to make it work.  In the end, just to be safe, we went with hardened Smith Bros. 5/16 rods.  At that time we double checked all the guides and all the exhausts needed to be replaced and most intakes.

I really like the heads as we run them hard and make good power.  There are just some questions that need to be asked of 440 Source, as to why they keep producing the heads knowing that the aftermarket Rockers with 3/8" rods cause the need for major mods to the head?  Why not just clearance them in the casting process?  Not to mention they sell 3/8" rods on their site to work with these heads.  I called them and they said there could be "core shift in the block".....BS.  Fix the issue 440 Source as 98% of us run aftermarket Rocker arms.

I agree. I bought CNC ported Stealths and use Crane iron rockers with 3/8" pushrods. It was a lot of work to get enough clearance for the pushrods with 1.5 rockers. I assumed the clearancing would have been done at MCH but I was wrong. The Edelbrock heads that I replaced had no problem with the 3/8" pushrods and 1.6 rockers.

[heyoldguy]

What if we go ahead and add the Stage VI to the mix? This time let's throw in some ported intake volumes and flows and compare those to the stock RPM volume and flows.

............210cc Stock RPM.....228cc Stg VI.....234cc Stealth.....244cc Stg VI.....249cc Stealth.....259cc RPM

.100".............71......................85....................77....................75....................73....................84
.200"............155....................157...................153..................150..................152...................158
.300"............205....................214...................216..................215..................218...................215
.400"............252....................261...................265..................267..................267...................252
.500"............275....................299...................306..................311..................308...................299
.600"............286....................313...................324..................341..................336...................328
.700"............287....................333...................337..................346..................346...................341

Can we make this relevant to something? Well we have yet to dyno test anything except for the last column, the 259 cc RPM heads. If you noticed in earlier posts, there are now RPM heads that flow even more than those listed here. But what do THESE flows give us on the dyno?

How about 770-780 HP?

Those results are shown in the Proven Engine Combos, http://www.dodgecharger.com/forum/index.php/topic,78039.0.html

Does this mean, that if you already have one of these heads, and you just have it ported, that you don't have to buy another more expensive, bigger port, aluminum head, that you STILL HAVE TO PORT to get 750 HP?

Yes, the Indy, Brodix, Victor and others can make these horsepower levels and more. How many of us need more than 750 HP? Buy the bigger heads if you don't already have your heads, or if you are going above 750 horses. But if'n ya'll 'ready haz the Stealth, RPM or Stage VI, pay for the porting of your old heads, 'cause we've already shown you don't need the bigger heads.

340-350cfm from the smaller heads ain't cheap, but it's less than the cost of new heads and paying to have THEM ported.

The Max Wedge port heads will work well on your 440-500" engines. But do you need them if you already have something else? I don't think so, but I'm open to opposing opinions offered, with some sort of supporting evidence.

[Budnicks]

What if we go ahead and add the Stage VI to the mix? This time let's throw in some ported intake volumes and flows and compare those to the stock RPM volume and flows.

............210cc Stock RPM.....228cc Stg VI.....234cc Stealth.....244cc Stg VI.....249cc Stealth.....259cc RPM

.100".............71......................85....................77....................75....................73....................84
.200"............155....................157...................153..................150..................152...................158
.300"............205....................214...................216..................215..................218...................215
.400"............252....................261...................265..................267..................267...................252
.500"............275....................299...................306..................311..................308...................299
.600"............286....................313...................324..................341..................336...................328
.700"............287....................333...................337..................346..................346...................341

Can we make this relevant to something? Well we have yet to dyno test anything except for the last column, the 259 cc RPM heads. If you noticed in earlier posts, there are now RPM heads that flow even more than those listed here. But what do THESE flows give us on the dyno?

How about 770-780 HP?

Those results are shown in the Proven Engine Combos, http://www.dodgecharger.com/forum/index.php/topic,78039.0.html

Does this mean, that if you already have one of these heads, and you just have it ported, that you don't have to buy another more expensive, bigger port, aluminum head, that you STILL HAVE TO PORT to get 750 HP?

Yes, the Indy, Brodix, Victor and others can make these horsepower levels and more. How many of us need more than 750 HP? Buy the bigger heads if you don't already have your heads, or if you are going above 750 horses. But if'n ya'll 'ready haz the Stealth, RPM or Stage VI, pay for the porting of your old heads, 'cause we've already shown you don't need the bigger heads.

340-350cfm from the smaller heads ain't cheap, but it's less than the cost of new heads and paying to have THEM ported.

The Max Wedge port heads will work well on your 440-500" engines. But do you need them if you already have something else? I don't think so, but I'm open to opposing opinions offered, with some sort of supporting evidence.

Thanks HeyOldGuy I know that is a tremendous amount of work, thanks for sharing it with us...

[Tom Cannon]

HeyOldGuy,

I race in the FAST class and have to use factory castings. Do have a idea what your best flowing 906 heads would cost? The ones that flow 340 cfm ?

Thanks, Tom

[heyoldguy]

HeyOldGuy,

I race in the FAST class and have to use factory castings. Do have a idea what your best flowing 906 heads would cost? The ones that flow 340 cfm ?

Thanks, Tom

Hello Tom,

Whoa, I never stopped to figure the cost.  I never figured we would do those for anyone, well, other than ourselves. Hmm, for the best flowing. A pair of heads, ported, milled, intake surfaced, with balanced combustion chambers, valves, guides, seals, springs, retainers and locks, could cost $5,100. Maybe less, depending upon how they are set up. So I suspect we won't doing very many sets for others. They're just a darn site more time consuming than the aluminum heads.

If you haven't already done so, you can look in Proven Engine Combo's here, to see what we have accomplished with some of our ported heads on our builds.

Jim LaRoy
LaRoy Engines
Challis, ID

[Budnicks]

Thanks HeyOldGuy/Jim.... Great information...

[c00nhunterjoe]

So do you port the crap out of edlebrocks, or buy the tall port indy's?

[heyoldguy]

The answer to that would be YES! Either, or.

I keep saying this, "You have to be smarter than your cylinder heads!" What do you want? How much money do you want to spend? Let's put our brains in gear and think for a minute.

Take into consideration what heads you already have and where you want to go. ANY aftermarket big block aluminum head that you ALREADY OWN can be ported to about 750 horsepower for $1800. ANY OF THEM! Now, what would it cost you to buy another set of aluminum heads and have them ported to 750 HP? Because you cannot buy an OOTB aftermarket aluminum head that will make 750 HP unless it is already CNC ported. Can you buy new, ported heads, cheaper than having the heads you already own, ported?

If you want 700 horsepower or more, and don't own any aluminum heads, don't buy a Stealth or RPM head to start with, get something better and have THEM ported.

And for cryin' out loud, don't try to do it with an factory iron head unless that is the only thing you are allowed to run!

[c00nhunterjoe]

Well here's the thing,

1st, you all will call me crazy but my next project is a new 383, not stroked, just a 383. I love the engine where most others hate it and only acknowledge its existance for stroker use. I'm at the limits of the current build so I'm starting fresh.

It will be pump gas, I already have 88cc edlebrock rpm heads, so I guess based on your above info I should just port them rather then buy a different set. But for 1800 I can buy the max wedge indy's that should outflow the eddy's. Just weighing my options.

[heyoldguy]

Well, you can do that, but how tight do you plan to wind this pump gas 383? Because with Max Wedge Indy's I figure it's efficient power range will be between 8,000-10,000 rpm. Should work good on the high banks of Daytona. For the 383, you already have enough cylinder head for 6500-7000 rpm  and to make 1.6 hp/ci or about 610 hp. In your case, I'd run what I got unported.

[c00nhunterjoe]

That's kind of what I was looking for. There is a guy with a 276 small block chevy turning 12,000+ rpm running 9's I believe in a nova. Its something you don't see often and definatly not in the mopar world. Everybody has big block, large cube strokers nowadays and I think I want to break the norm. I may try the heads as is. I can always upgrade

[Cooter]

There's a guy here that used to run in that NMCA/King-of-Street Class with a 378 C.I. Small block Mopar in a 1965 Barracuda. Sure it runs in the 8.30 range 1/4 mile @ like 170 MPh, but it's a 25 year project that cost him well over 500K in that time frame. Sure, it's cool and all to be able to brag that your "Out of the norm" "little" 383 went 9's, but it will cost like hell. I've witnessed this guy blow up two $20K engines....Turn around and say "Well, time to start over"..At that point, most Mopar people have $30K to invest in the whole car.....Not just the engine.


At the same time, Sonny Leonard here in Va., Has an 800 C.I. Pontiac "Big Chief" engine in his '57 Chevy. Electronic Fuel injected, Noramlly aspirated, 1200 HP on pump gas. Sure it is trick as hell, but every time I see it, I think to myself, "So that's what $300K car looks like"...

[c00nhunterjoe]

I guess I should have noted that I'm not looking for a 9 second drag car. Lol. Heads are the key to any engine, no matter what the intended build. I was merely looking for advice on stock port or aftermarket design ports.

[Budnicks]

I guess I should have noted that I'm not looking for a 9 second drag car. Lol. Heads are the key to any engine, no matter what the intended build. I was merely looking for advice on stock port or aftermarket design ports.

You probably already know this but I will put it out there anyway... If you go the Indy "Max Wedge" or any other "Max Wedge" head route, you will need a different intake & many other tuning parts, carburetor, camshaft, valve train components, larger intake valve to piston or cylinder wall clearance &/or shrouding issues possibly also, some MW heads will require special oiling & valve train components, to make the new combo perform, the way they are advertised, "to be able to perform", it's allot more than just buying the new set of heads, now you will need to match the combo with the much larger higher RPM range of the new larger volume cylinder heads, to get the reported/advertised gains in power... Trust me, They are never what they claim to be, out of the box, ever...

[c00nhunterjoe]

Yup, its pointless to put a small intake on top of big heads. I was looking at the max wedge heads with the factory oiling. I didn't want to step up to the external setup they have. I know about the rockers anddifferent pushrods.  BUT, I trust your opinion about the eddys, I will stick with them for my project.