Gain from Stock 452s to OOTB Stealths?

[67Satty]

I figure my bone-stock, stock-sized valve, unported 452s flow 220-230 at best and OOTB Stealths flow 250 or so.

So what would my gain in HP be going from my 452s to OOTB Stealths? 40 to 60 HP?

What would my reduction in ET be in the 1/8th? Current best time without much tuning or many runs (17) is 8.25 in the 1/8th with a 1.77 60 foot. Rest of combo is in my signature. Car weighs 3780 with driver.

Just trying to weigh my options moving forward with this. I'm considering the Edelbrock RPMs as well. Thanks!

 

[Budnicks]

Your guess is as good as mine in ET/MPH improvement, maybe 3-5 tenths, lots of factors to weight... Just the extra 70lbs off the front end will make a difference... The O.O.T.B. Stealths flow better than you think... A good rule of thumb is 2.06 Hp/per cfm of flow... There are lots of factors to compare, combustion chamber size, head gasket thickness, port volume, flow rate, valve spring rating, valve sizes, rockers style/ratios, weather you can use your sock style or existing valve train components, etc.... Nothing should be bolted on out of the box, from either company, checked them out & cleaned very thoroughly at a minimum {or have them checked out}, before you install them... If you have a stock short block or flat top pistons, I personally like the 84cc/291cfm 2.14"int/1.81"ext Edelbrock RPM's, slightly more, they have "better parts to begin with" {than the O.O.T.B. std. Stealth's}, like valve springs, retainers, locks & seals, gross lift up-to 0.600" {I have a mildly ported set of them on my street/strip 68 RR}... There are also a new E-Street Edelbrock 75cc combustion chambers, you may also want to consider {$980 a pair from Summit Racing, but they are back-ordered} for lower compression stock type short blocks, were you want more compression & better flowing Aluminum heads, they flow the same as the RPM's supposedly... There is nothing wrong with using the Stealths if that your choice {but they are foreign made & have inferior parts}... I prefer using American Made products when ever possible, even if I have to spend a few hundred more bucks, Edelbrocks are all 100% U.S. made... Have fun, Happy Hunting & Happy Moparing....

 

[67Satty]

440Source is running a deal now where they upgrade the locks and retainers to Comp Cams stuff at no extra cost. So that would take care of that problem. The springs they come with should work for my cam.

But yeah, if I have to spend close to $500 to sort them out and get a valve job on the Stealths, then I may as well buy the Edelbrock RPMs for $1500 if they are more ready to go OOTB.

I'm really intrigued by the Edelbrock E-Streets, seems like a great deal for the money, especially if they flow the same as the RPMs.

 

[Moparmatt72]

Either way you go stalths or edelbrock have them checked, I bought some stealths had them checked and some valve guides were a little warpped, a little honing and they were good to go, anything mass produced should be check like Budnicks said. All in all I do like my stealths I ported them and can't wait to fire my engine up and see what they do.

 

[bigmanjbmopar]

I have the stealth heads, bolted them in and fired them up even with wrong adjustments on the push rods they worked great. I typicality blow most cars away on the street, to date - 1 - 69 camaro rs/ss, 1 - 2009 mustang GT, 1 - 2011 Acura something blah blah lmao all in good fun and safety. 1/8 to 1/4 mile romps

440source will openly admit the aluminum is cast in china but assembled here at their shop in L.A., Ca. I bought the 1.5 ratio rockers set up from them with the spacers to make sure the rollers were centered and haven't looked back. Very Pleased with them well worth the money

 

[67Satty]

Edelbrock E Streets #5090

There are also a new E-Street Edelbrock 75cc combustion chambers, you may also want to consider {$780 a pair from Summit Racing, but they are back-ordered}

Just got off the phone with a woman in the sales department at Edelbrock. She told me the part number 5090 75cc E-Streets are "still in development" and that they are still "working out pricing" and that "they will be out in four to six weeks". That's all I could get out of her.

Next, I called Summit Racing. The guy in sales there told me that they are supposed to be released July 27 and that they will cost $979. He thought that was each, but I told him that is probably per pair or else they would be more than the RPMs.

So it kinda looks like they are going to try to beat 440Source at their own game, undercutting them by $20. It will be interesting to see if they flow better out of the box compared to Stealths and if they come with better quality. If so, it will be a no-brainer of which one to get.

 

[Budnicks]

Just got off the phone with a woman in the sales department at Edelbrock. She told me the part number 5090 75cc E-Streets are "still in development" and that they are still "working out pricing" and that "they will be out in four to six weeks". That's all I could get out of her.

Next, I called Summit Racing. The guy in sales there told me that they are supposed to be released July 27 and that they will cost $979. He thought that was each, but I told him that is probably per pair or else they would be more than the RPMs.

So it kinda looks like they are going to try to beat 440Source at their own game, undercutting them by $20. It will be interesting to see if they flow better out of the box compared to Stealths and if they come with better quality. If so, it will be a no-brainer of which one to get.

That was a typo on my part, I corrected that, the Edelbrock E-Street are offered by Summit Racing for $979.95 a pair {not $780 a pair}, they will ship when they receive them, Summit Racing are & will have to honor their advertisement price of $979.95 a pair... I talked to an Edelbrock sales phone tech. also they told me, she was clueless, almost the same thing as they told you, then I talked to an engineer/superviser & he said it's set backs is in CNC machining back log, they are all-ready developed & would ship soon with in 60 days, that was over a month or 2 ago, that's why I said they were still back ordered... That deal with the 440Source using Comp Cam Components at no extra cost, sound like a good deal on the Stealths, that has always been a deturent to many people, besides the Chinese made castings...

 

[67Satty]

I know this goes against the conventional wisdom these days but I'm considering sticking with my trusty 452s and having some port work done to them.

I spoke with an engine builder/head porter and he made some pretty convincing arguments against using any of the aluminum heads on a 440-powered street/strip car with a cam smaller than .600 lift.

He said that both the Stealths and Edelbrock's 210cc intake runners and bigger valves will kill velocity and make my bottom end too soft. He said low lift numbers on both are also pretty bad. He was saying you don't benefit from these types of heads vs. ported stock iron heads until you get over 500 cubic inches and over .600 lift cams. He backed up what he was saying with real-world ETs and dyno runs to support his ideas.

For example, he had a car with a set of Mopar Performance Max Wedge heads with a gasket match and lite bowl cleanup cc'd out at 230 cc's. The car ran 7.30's at 99-100 1/8 mile. He replaced the Max Wedge heads with a set of 346 heads with a good gasket match and some bowl work in them and ported the exhaust side (basically the same port work that was done to the Max Wedge heads). He said after installing them on the engine because the heads were some 50+ cc's smaller than the MW heads the port velocity came way up. He said the airflow that they made literally blew the other heads off the map up to .600 lift and were better at .700 and .800 lift by some 15 cfm's. The car then ran .5 tenths faster in the 1/8 mile and the MPH came up 5-6 MPH. The car ran 6.88 @ 106.89 with no other changes than going from the Max Wedge heads to the 346 "smogger" heads with similar porting.

He's saying with some minor port work, I will go faster/make more power with my factory iron heads than any of the aluminum offerings. Again, we're talking about 11-12 second street/strip cars with pump gas-friendly compression, less than .600 lift cams and street-friendly gears and converters.

Next, I spoke to a machinist/engine builder in town with a good reputation for knowing Mopar stuff. He told me that all of the Stealths he has seen have been fine quality-wise and that it would only cost me another $150 for him to set them up and correct any issues. He said they will flow better even at the low lifts than ported iron right out of the box.

BTW, first guy in this long story claims both Edelbrocks and Stealths are cast in the same place in China.

 

[Budnicks]

Call or e-mail Jim & Cody @ LaRoy Engines in Challis Idaho, IQ52 on here sometimes, {I don't want to give out the #'s here, he can if he sees this post} he is a great Professional head porter & Professional Engine Builder, that is a real Mopar enthusiast too boot, he will tell you what is the truth, with out the salesman's pitch... Yes a set of well ported 452's can perform very well, especially after a couple of thousand dollars in parts, bowl & port work, but you still have a 40 year old set of heads that are 55-70lb heavier cast iron, money could be better spent on some of the better aftermarket aluminum wedge heads, that will out flow out of the box, allot of the so called ported cast iron heads, that have far more room for improvement, in the future... Just my $0.02 cents

 

[Budnicks]

wrong

BTW, first guy in this long story claims both Edelbrocks and Stealths are cast in the same place in China.

He is 100% totally wrong... the Edelbrocks are 100% American Made, Cast & machined, all parts, including the valves, retainers, spring, locks & seals too all American Made Only the Stealth's of those 2 were cast in CHINA...

 

[Budnicks]

Correct mostly

Next, I spoke to a machinist/engine builder in town with a good reputation for knowing Mopar stuff. He told me that all of the Stealths he has seen have been fine quality-wise and that it would only cost me another $150 for him to set them up and correct any issues. He said they will flow better even at the low lifts than ported iron right out of the box.

That's probably pretty close to being accurate, but the stock locks & retainers are junk, the springs should be checked to see if they are correct for your exact camshaft you end up, the proper installed height is also important, a quality multi-angle performance type valve job or checking them at a minimum, with on any head you choose, cast iron or aluminum... The cylinder heads is probably the single most important performance addition you can do to any race or street engine period... The too big of port arguement is just BS until you get over 230cc or 350cfm on larger displacement engines over 450ci minimum & there are people that will say you can make up all the power you want with the big heads & large ports, with a well choosen camshaft, induction & exhaust... J.M.H.O. -------------------------------------A wise old engine builder once told me there are many things you have to know when building a race/performance engine, the 1st 3 are #1 Cylinder Heads #2 Cylinder Heads #3 Cylinder Heads , with out the engine breathing freely they will never run to potential, with out the flow of a good head... Professional racers & Professional engine manfgrs. & builders, Jim LaRoy, Paul Phaff, Ed Pink, Joe Pisano, Keith Black, Ed Mondello, Brad Anderson, Bob Glidden, Allen & Roy Johnson, Warren & Kurt Johnson, Raymond Beatle, Dale Armstrong, among others all seemed to agree... I know, I know you don't want to hear this... for example a Stock BB Chevy 427/454 Rect. Port heads will volume/flow 280cc/330cfm any day, they can go out to 300cc & 400cfm when professional done, that's why it's so easy to make BB Chevy's over 800hp with Iron Heads or any head for that matter, the choke point in a Big Block Mopar Wedge has & is the cylinder head & it always has been, the Max wedge was a start on the right track, with the proper camshaft... a good rule of thumb is 2.06 hp/per CFM of flow...

 

[IQ52]

I know this goes against the conventional wisdom these days but I'm considering sticking with my trusty 452s and having some port work done to them.

I spoke with an engine builder/head porter and he made some pretty convincing arguments against using any of the aluminum heads on a 440-powered street/strip car with a cam smaller than .600 lift.

He said that both the Stealths and Edelbrock's 210cc intake runners and bigger valves will kill velocity and make my bottom end too soft. He said low lift numbers on both are also pretty bad. He was saying you don't benefit from these types of heads vs. ported stock iron heads until you get over 500 cubic inches and over .600 lift cams. He backed up what he was saying with real-world ETs and dyno runs to support his ideas.

For example, he had a car with a set of Mopar Performance Max Wedge heads with a gasket match and lite bowl cleanup cc'd out at 230 cc's. The car ran 7.30's at 99-100 1/8 mile. He replaced the Max Wedge heads with a set of 346 heads with a good gasket match and some bowl work in them and ported the exhaust side (basically the same port work that was done to the Max Wedge heads). He said after installing them on the engine because the heads were some 50+ cc's smaller than the MW heads the port velocity came way up. He said the airflow that they made literally blew the other heads off the map up to .600 lift and were better at .700 and .800 lift by some 15 cfm's. The car then ran .5 tenths faster in the 1/8 mile and the MPH came up 5-6 MPH. The car ran 6.88 @ 106.89 with no other changes than going from the Max Wedge heads to the 346 "smogger" heads with similar porting.

He's saying with some minor port work, I will go faster/make more power with my factory iron heads than any of the aluminum offerings. Again, we're talking about 11-12 second street/strip cars with pump gas-friendly compression, less than .600 lift cams and street-friendly gears and converters.

Next, I spoke to a machinist/engine builder in town with a good reputation for knowing Mopar stuff. He told me that all of the Stealths he has seen have been fine quality-wise and that it would only cost me another $150 for him to set them up and correct any issues. He said they will flow better even at the low lifts than ported iron right out of the box.

BTW, first guy in this long story claims both Edelbrocks and Stealths are cast in the same place in China.

Wow, he said the small aluminum heads will destroy the port velocity in a 440. Then to prove the point he compared ported Max Wedge iron heads to ported 346 passenger car heads. Hmmm.

The Stealth or RPM heads will work great, even on a 383, but, so will ported iron heads.

As to the OOTB Stealth out flowing the ported iron heads, well, here are OOTB Stealth flows and 452 and 906 heads ported by LaRoy Engines.

Lift.................Stealth...................452.............906


.100"...............66.........................90...............89
.200"..............142.......................166..............166
.300"..............205.......................218..............218
.400"..............240.......................255..............258
.500"..............255.......................278..............292
.600"..............267.......................288..............323
.700"..............268.......................294..............332

It just really depends the purpose you have in mind for the cylinder head.
One port job doesn't fit all. You can tailor a cylinder head for a camshaft and RPM range if you want. Make adjustments for duration, lobe centers and lifts.

You must be smarter than your cylinder heads.

 

[bigmanjbmopar]

Well all the data in the world is great but all I can say is my 493 with stealth heads non cnc'ed rip the pavement up pretty well and I only paid $500.00 for the head you do the math as many ways as you want it's all just a matter of preference I guess ;) maybe it's just the complete package I have and the heads just are lighter boat anchors I don't know.

Her is a little blip about the stealth heads and now a I see they are $499.00

Clearanced for large diameter valve springs, our Stealth heads use factory type rocker arms and stock diameter shafts, so no special "high-dollar" offset rockers are required. Any rockers that work on a stock Mopar head will work on our heads. This includes roller rockers, or even stock type stamped steel rockers. Heat crossover is blocked off for increased performance. Factory port windows, exhaust and intake manifold locations make sure you can use any "off the shelf" intake manifold and/or exhaust manifold/headers without any fitment hassles or special "spacers" required. Made of lightweight aluminum alloy, one of these heads weighs only 22 pounds bare or 29 pounds complete with valves and springs.

good luck in what ever you go with just post lots of pics

 

[Al K]

First off;great thread and great info. I'd like to pose a question myself,which may or may not confuse the issue(s).

Where do Mopar Performance Stage V heads fall in this equation? Weren't they similar to 452/346 in port size/configuration? I have one(-B;with exhaust crossover and 2.14/1.81" valves),would like to find another and do basic bowl cleanup and port-matching. However...a set of bare Stealths are appealing.

Something else to consider: Dimensional differences due to casting process differences. A head cast with "old" cores is going to flow differently from a head with "new" cores. Core shift can also play into this. Won't matter if it's aluminum or iron. Back in my Engineering days,this very subject came up. Heads were pulled off a Buick V-6(directly from the Engine plant),checked for casting date/shift,stripped,and run on a Superflow bench at 28". Minimal difference(1-3 cfm) in the .100-.300" lift area,but...after that,somewhat noticeable changes. Like(if I recall...) an approx. 20 cfm difference at .400 and .500 lift. Visual inspection showed differences in the two heads as far as the "bumps and humps" factor in the ports and chambers. Oh;the difference in the heads? Approximately one week in their casting dates.

Seems like one would have to acquire two heads cast consecutively in order to get matching flow rates. Or fire up the CNC. That make any sense? I hope so.

 

[IQ52]

First off;great thread and great info. I'd like to pose a question myself,which may or may not confuse the issue(s).

Where do Mopar Performance Stage V heads fall in this equation? Weren't they similar to 452/346 in port size/configuration? I have one(-B;with exhaust crossover and 2.14/1.81" valves),would like to find another and do basic bowl cleanup and port-matching. However...a set of bare Stealths are appealing.

Something else to consider: Dimensional differences due to casting process differences. A head cast with "old" cores is going to flow differently from a head with "new" cores. Core shift can also play into this. Won't matter if it's aluminum or iron. Back in my Engineering days,this very subject came up. Heads were pulled off a Buick V-6(directly from the Engine plant),checked for casting date/shift,stripped,and run on a Superflow bench at 28". Minimal difference(1-3 cfm) in the .100-.300" lift area,but...after that,somewhat noticeable changes. Like(if I recall...) an approx. 20 cfm difference at .400 and .500 lift. Visual inspection showed differences in the two heads as far as the "bumps and humps" factor in the ports and chambers. Oh;the difference in the heads? Approximately one week in their casting dates.

Seems like one would have to acquire two heads cast consecutively in order to get matching flow rates. Or fire up the CNC. That make any sense? I hope so.

The Stage IV iron head was more like 452/346 heads and the Stage V was more like the 906 but with much better exhaust ports.

 

[67Satty]

Engine builder/head porter #1 (the guy in favor of smaller ports and valves for motors under 500 ci with cams under .600 lift) had another story.

He told my about a small block Mopar that started off with heads with 2.02 intake valves. They swapped on some heads with 1.88 intakes and went faster. To see what would happen they swapped on some heads with 1.78 intakes and went faster still. I don't know why you would make up something like this but I guess anything is possible. He just didn't strike me as a BS artist or someone try to sell me something, he just seemed to like to talk my ear off about Mopars and drag racing.

BTW, what he was proposing to sell me was $700 of work on my stock iron 452s to get me into the 11s with my current combo. He proposed we keep the stock-sized valves, gasket match the intake, machine cut the bowls, port the exhaust ports, and give it another valve job. I would think if he was just trying to sell me on a job and get my money he could've thought of a lot more than that to do, like suggesting I put bigger valves in like most people automatically do. He also knew I was interested in the Stealths and Edelbrocks and he could've suggested almost the same dollar amount of work on either of those to get them right without straining his credibility considering the CNC-ported Stealths or Edelbrocks usually sell for $1000 more than OOTB.

Engine builder/head porter #2 made the point that the small valve sizes and ports for big-block Mopars were more or less established when the motors first came out in the '50s as 350 cubic inch motors and never got much bigger so that's why a 440 needs the bigger valves and ports.

But I wonder why the BB Mopars performed so well with the small valves in the muscle car era? How was a 440 6 pack with its small valves and small ports able to hold it's own against big block Chevys with their huge in comparison valves and ports? Or said another way, if big ports and valves are so important, why didn't the Chevys perform better than they did?

If you look at FAST racing, the two motors that are on top are the Hemi and the big block Chevy, two motors with big valves and ports. But those FAST guys are running gigantic roller cams to take advantage of those big heads.

It would be great if one of the magazines would run a head swap drag strip flog comparison test. Run a car down the strip with fresh, stock iron heads, swap to ported iron heads, then swap to OOTB Stealths, then to OOTB Edelbrocks, then to ported Stealths, then to ported Edelbrocks. The test mule would be something like a B Body with a cam in the mid .500 lift and 240-250 @ .050 duration range, in other words something realistic that a lot of people are driving as a street cruiser/strip weekend warrior.

P.S. Just to add more fuel to the fire, machinist/engine builder/head porter #2 who runs a very respected, long-established shop said that every pair of Stealths he has run across have looked fine and that he would probably only have to charge me $150 to check them out and set them up for me and said he would do the same things to the Edelbrocks.

Fuel to the fire #2, I recently saw some of the Mopar Performance heads made by Edelbrock on eBay. They were listed for a starting bid of only $300 with no reserve because they had big porosity holes in them on the head gasket surface. Can this kind of thing be welded up and fixed? But then, if there are that many holes in a surface you can see are there going to be more holes in areas you can't see and get to to repair?

 

[Moparmatt72]

I remember last time Mopar mag compared the stealths to the RPMs they tested at different flow rates, stealths at 0.500 and the RPMs at 0.700, now they only ported the RPMs and made over 300 cfm but they didn't port the stealths the same and retested. I would like to see them do a test like you said but it seems like they favor the more popular heads, its never been a equal test. Id like to see stealths, RPMs, and 906 all ported the same way and tested all at say .500 where most people have their set ups, not up around .700 where only race engines use that high a lift.

 

[IQ52]

I remember last time Mopar mag compared the stealths to the RPMs they tested at different flow rates, stealths at 0.500 and the RPMs at 0.700, now they only ported the RPMs and made over 300 cfm but they didn't port the stealths the same and retested. I would like to see them do a test like you said but it seems like they favor the more popular heads, its never been a equal test. Id like to see stealths, RPMs, and 906 all ported the same way and tested all at say .500 where most people have their set ups, not up around .700 where only race engines use that high a lift.

First off, you cannot port the Stealth/RPM heads like the 906 because the ports are a completely different shape. The 906 heads take a great deal more work to get the same flows as the Stealth/RPM. But here are ported Stealth, RPM and 906 heads with flows stopping at .500"

Lift.............Stealth.................RPM.................906

.100"............77.......................84....................89
.200"...........152.....................158...................166
.300"...........218.....................215...................218
.400"...........267.....................252...................258
.500"...........308.....................299...................292

AVG.............204.4..................201.6................204.6

Notice, you can move the flows around at different lifts to have the head work where you want it to.

AGAIN, it really depends upon what type of performance you are porting for. There is no one magic grind for every cylinder head.

 

[Budnicks]

Go to MMM to see comparisons

I remember last time Mopar mag compared the stealths to the RPMs they tested at different flow rates, stealths at 0.500 and the RPMs at 0.700, now they only ported the RPMs and made over 300 cfm but they didn't port the stealths the same and retested. I would like to see them do a test like you said but it seems like they favor the more popular heads, its never been a equal test. Id like to see stealths, RPMs, and 906 all ported the same way and tested all at say .500 where most people have their set ups, not up around .700 where only race engines use that high a lift.

NOT Just you, but anyone interested in the subject of cylinder head comparisons, I suggest Go to Mopar Muscle Magazine forum {then come back here & post your thoughts} look in the Search Mopar Muscle feature, there are tons of cylinder head comparisons , by me {never mind the bad spelling...LOL...} & a few other very knowledgeable posters here like IQ52, HeyOldGuy & many others, it's a good read, lots of great information with pages & pages of Cast Iron Vs Aluminum heads, Edelbrock Heads, Stealth Heads threads, Ported & un-Ported, out of the box flow #'s, covering Stealths & Super Stealths, Edelbrock RPM's & Victors, Mopar Performance Max Wedge, 346, 915, 906 etc. iron & aluminum versions, Stage V & Stage VI std. & MW Large Port, Indy EZ SR & others, Bull Dog, Pro Comp, Brodix B1 & others, with many suggestions too boot... do a GOOGLE search for Mopar Aluminum Heads or Mopar Cast Iron Heads you can find a ton of threads on a ton of forums with many opinions {like *** holes, everyone has one} & facts, with many lies too boot..... If your going to by a set of heads, aluminum or cast iron, it is worth the time to gather "all the information needed".... Any head can be ported, some are easier than others, some are far better than others to start with, some aren't worth the time when you can just purchase a ported set of heads for near the same amount of money or have your current heads ported by a Professional Head Porter, that is very familiar with what needs to be done with a Mopar Wedge head, not the local yokels, that claims to know what they are doing... It's not just all about the cost, it's about cost vs quality vs workmanship, with the proper port job, valve job & components for your intended use, the cheapest parts stuff is usually, cheap parts stuff, for a good reason, sometimes spending a little more is a good thing, in the long run...

 

[Moparmatt72]

Hosnestly didn't think to do a search on that lol thanks for all the info