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Re: Iron heads vs. Stealths
[Re: ademon]
#440867
08/17/09 02:02 PM
08/17/09 02:02 PM
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Joined: Aug 2004
Posts: 3,392
cheshire, ct
davesmopars
master
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master
Joined: Aug 2004
Posts: 3,392
cheshire, ct
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if everything is the same, iron heads make more power
Keeper of the 440 M code Cuda registry
mcodecuda@yahoo.com
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Re: Iron heads vs. Stealths
[Re: davesmopars]
#440868
08/17/09 02:37 PM
08/17/09 02:37 PM
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Joined: Nov 2004
Posts: 843
Suffolk,VA
ireland383
OP
super stock
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OP
super stock
Joined: Nov 2004
Posts: 843
Suffolk,VA
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The 346's have the stock valve sizes. I thought I would benefit with the larger valves of the stealths, also the weight factor. I'm not sure how much can be shaved off the stealths with running a domed piston. I'm sure I'm close to 10 to 1 now. One other thing I thought would be better is the closed chamber of the stealths.
Last edited by ireland383; 08/17/09 02:56 PM.
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Re: Iron heads vs. Stealths
[Re: davesmopars]
#440869
08/17/09 03:04 PM
08/17/09 03:04 PM
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Joined: Jul 2006
Posts: 4,319
Puyallup, WA
StealthWedge67
master
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master
Joined: Jul 2006
Posts: 4,319
Puyallup, WA
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Quote:
if everything is the same, iron heads make more power
Guys, are you kidding me? Seriously...... First off, the 346 head is an open chamber, so going to a stealth head would up the compression significantly.
Secondly, I don't even know what to say..... a stock set of 346 castings vs. a set of Stealths?? Is this a trick question? Is there something I'm missing? I'd say: no comparo. There's no way the 346 even come close.
Now, We need to know more about the combo. If you don't have the flow abilities on the intake side, or the exhaust side, to make use of the flow capabilities of the new heads, then maybe you wouldn't feel a difference ?? Tell us more about the entire combo.
LemonWedge - Street heavy / Strip ready - 11.07 @ 120
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Re: Iron heads vs. Stealths
[Re: ireland383]
#440871
08/17/09 03:28 PM
08/17/09 03:28 PM
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Joined: Jan 2005
Posts: 12,419
Kalispell Mt.
HotRodDave
I Live Here
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I Live Here
Joined: Jan 2005
Posts: 12,419
Kalispell Mt.
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Actual real world tests show very very little if any power loss from iron vs aluminum. I have seen several dyno tests of heads in iron and alumnium even as can be like CNC ported and there was no real world differance in the power, 2 or 3 tops on a 350 chevy. The aluminum head allows more compression, it does NOT require more compression.
As for your combo feeling weeker it could be a few things, mabey timing was not optimised for the new heads(they will need less timing) and the carb could be running lean with the extra airflow. Mabey the car is hooking better do to weight so now you can not roast the tires like you were. Mabey the tq converter needs adjusted also. Several things to look at before jumping to blame the heads. If there is a problem with the heads it would show up in a leakdown test(bad valve job).
I am not causing global warming, I am just trying to hold off a impending Ice Age!
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Re: Iron heads vs. Stealths
[Re: davesmopars]
#440872
08/17/09 04:35 PM
08/17/09 04:35 PM
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Joined: Dec 2007
Posts: 7,759
So Cal
HealthServices
Why would you even post that?
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Why would you even post that?
Joined: Dec 2007
Posts: 7,759
So Cal
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Power band and torque curve most likely changed. With the larger valves the bottom end torque could have changed. My 11.70 Pontiac felt like a high 13 second car because the torque curve was so flat. Maybe butt o meter needs recalibration? 
Allen
Here's a novel idea, let's not throw a bunch of parts at the car hoping it will fix the problem and instead spend a little time diagnosing it first.
Life was a little easier when I was just a wrench.
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Re: Iron heads vs. Stealths
[Re: HealthServices]
#440873
08/17/09 06:33 PM
08/17/09 06:33 PM
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Joined: Feb 2003
Posts: 12,675
Columbia, CT
moper
I Live Here
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I Live Here
Joined: Feb 2003
Posts: 12,675
Columbia, CT
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Give all the details of the engine. What cam? What intake? headers? convertor? gearing? carb?
Well, art is art, isn't it? Still, on the other hand, water is water! And east is east and west is west and if you take cranberries and stew them like applesauce they taste much more like prunes than rhubarb does. Now, uh... Now you tell me what you know.
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Re: Iron heads vs. Stealths
[Re: HotRodDave]
#440880
08/17/09 07:44 PM
08/17/09 07:44 PM
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Joined: Feb 2003
Posts: 21,318
Manitoba, Canada
DaytonaTurbo
Too Many Posts
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Too Many Posts
Joined: Feb 2003
Posts: 21,318
Manitoba, Canada
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Quote:
Actual real world tests show very very little if any power loss from iron vs aluminum. I have seen several dyno tests of heads in iron and alumnium even as can be like CNC ported and there was no real world differance in the power, 2 or 3 tops on a 350 chevy. The aluminum head allows more compression, it does NOT require more compression.
 I also remember reading an article where they used an identical set of aluminum and iron heads on a chevy build and they dynoed within a couple hp/torq of each other.
But, going from stock small port heads to bigger port aftermarket heads could have costed you some low end power due to a drop in port velocity. Also your new heads could be flowing enough more that you're leaning out under WOT.
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Re: Iron heads vs. Stealths
[Re: StealthWedge67]
#440881
08/17/09 10:15 PM
08/17/09 10:15 PM
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Joined: Jan 2003
Posts: 27,421
Balt. Md
383man
Too Many Posts
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Too Many Posts
Joined: Jan 2003
Posts: 27,421
Balt. Md
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Quote:
Quote:
Your running a dome piston with closed chamber heads ?? How far down in the hole are the pistons ? Ron
http://kb-silvolite.com/performance.php?action=details&P_id=327
He's got the right piston for these heads, Ron. KB400's are more of a flat-top with a dome section above the valves only. Pretty much designed around a closed chamber head. You can run these at zero deck with closed chamber heads.
Ok I should have looked at the piston first. Thanks , Ron
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Re: Iron heads vs. Stealths
[Re: StealthWedge67]
#440882
08/18/09 11:15 AM
08/18/09 11:15 AM
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Joined: Feb 2003
Posts: 8,020
Pangaea
B5 Bee
master
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master
Joined: Feb 2003
Posts: 8,020
Pangaea
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Quote:
Quote:
if everything is the same, iron heads make more power
Guys, are you kidding me? Seriously...... First off, the 346 head is an open chamber, so going to a stealth head would up the compression significantly.
Secondly, I don't even know what to say..... a stock set of 346 castings vs. a set of Stealths?? Is this a trick question? Is there something I'm missing? I'd say: no comparo. There's no way the 346 even come close.
Now, We need to know more about the combo. If you don't have the flow abilities on the intake side, or the exhaust side, to make use of the flow capabilities of the new heads, then maybe you wouldn't feel a difference ?? Tell us more about the entire combo.
That's a correct statement, everything the same (ports, valves, combustion chamber), an iron head will make more power.
It takes about a 1 point increase in compression, with everything else the same, for aluminum heads to make the same power.
As fas as 346 vs Stealth, the Stealths advantages still should overcome any power loss from the use of aluminum. I'd advance the timing 2 to 4 degreees till the Stealth heads can be cut or pistons are changed. More timing can be used as a crutch till the compression is raised.
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Re: Iron heads vs. Stealths
[Re: ireland383]
#440885
08/18/09 09:11 PM
08/18/09 09:11 PM
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Joined: Nov 2003
Posts: 36,040
Lincoln Nebraska
RapidRobert
Circle Track
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Circle Track
Joined: Nov 2003
Posts: 36,040
Lincoln Nebraska
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If you have quench you for sure can go considerably higher than 10:1(measured) w alum(not sure how much exactly)
live every 24 hour block of time like it's your last day on earth
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Re: Iron heads vs. Stealths
[Re: B5 Bee]
#440886
08/18/09 11:58 PM
08/18/09 11:58 PM
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Joined: Feb 2003
Posts: 21,318
Manitoba, Canada
DaytonaTurbo
Too Many Posts
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Too Many Posts
Joined: Feb 2003
Posts: 21,318
Manitoba, Canada
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Quote:
That's a correct statement, everything the same (ports, valves, combustion chamber), an iron head will make more power.
It takes about a 1 point increase in compression, with everything else the same, for aluminum heads to make the same power.
Where's the proof on that? I'd be very interested in reading it because the only article I've ever read where they tackled this subject on the dyno showed no change in power output between the two materials, everything else being equal...
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Re: Iron heads vs. Stealths
[Re: ireland383]
#440887
08/19/09 12:00 AM
08/19/09 12:00 AM
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Joined: Nov 2004
Posts: 2,825
Sk. Canada
RemCharger
master
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master
Joined: Nov 2004
Posts: 2,825
Sk. Canada
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Quote:
Why would my motor feel like it has more power with my 346 heads shaved .030 vs the new 440 source heads? It has KB 400 pistons and both heads had the same head gaskets. 
I think something isn't set right. Gas pedal,,timing,,puel press,,float level,, rocker geometry,, 
The other issue is how fast did , and how fast does, it run the 1/4?
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Re: Iron heads vs. Stealths
[Re: ireland383]
#440888
08/19/09 03:17 AM
08/19/09 03:17 AM
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Joined: May 2008
Posts: 5,399
Aurora, Colorado
451Mopar
master
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master
Joined: May 2008
Posts: 5,399
Aurora, Colorado
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Quote:
Why would my motor feel like it has more power with my 346 heads shaved .030 vs the new 440 source heads? It has KB 400 pistons and both heads had the same head gaskets.
What head gasket? The stealth heads need to use the larger diameter head gasket. The fel-pro 1009 has too small a bore diameter. The standard Fel-Pro rebuild kit gasket 8519-PT seems to fit OK with the stealth heads.
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Re: Iron heads vs. Stealths
[Re: goldmember]
#440890
08/19/09 04:56 AM
08/19/09 04:56 AM
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Joined: Jan 2005
Posts: 4,862
the frozen wastes...
Pale_Roader
Swears too much
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Swears too much
Joined: Jan 2005
Posts: 4,862
the frozen wastes...
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Quote:
"feels like" isn't really very accurate. As others have pointed out the are some tuning issues likley to be found,but you'll need to test. I understand your ??? as I've found through track testing that things are far from certain in parts swapping,even if all the mags (and internet pros) say otherwise. LOL Good luck to you.
I'm with goldmember on this one. My 96 Mustang GT feels much faster than my 440 Charger. It is not. They both feel way faster than my old 70 Skylark 455... and again, not even close.
Possibly the extra port volume killed enough low end to soften the experience a bit? It should be way better in the top end, but unaddressed there are tons ov issues that could limit that too. When i swapped a ported Street Dominator onto my stock 72 440 i got nothing out ov it. Nothing at all in the SOTP. After jetting up and up and up and up again, i couldn't keep the back tires from spinning. The difference was VAST. Also, if the bigger heads didn't improve the lot, perhaps the 346's were not the limiting factor. You might have a glaringly weak link in your combo that has now been multiplied?
Regardless, you've done the best thing... replaced that stock junk. Figure it out and it should rock. Provided there is nothing WRONG with your particular heads, they should out-perform even max-ported stock heads any day.
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Re: Iron heads vs. Stealths
[Re: RemCharger]
#440892
08/19/09 07:04 AM
08/19/09 07:04 AM
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Joined: Nov 2004
Posts: 843
Suffolk,VA
ireland383
OP
super stock
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OP
super stock
Joined: Nov 2004
Posts: 843
Suffolk,VA
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I think something isn't set right. Gas pedal,,timing,,puel press,,float level,, rocker geometry,,
The other issue is how fast did , and how fast does, it run the 1/4?
Never had it to the track. I'm sure I gained more top end, but killed the low end. Partly I think it is the cam (275DEH) part # 21-406-4 which worked better with the iron heads. When I look this cam up at Summit, It is for a restrictive exhaust and an application where low end torque could be less. Would I benefit by going to a lunati 60302?
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Re: Iron heads vs. Stealths
[Re: DaytonaTurbo]
#440893
08/19/09 10:50 AM
08/19/09 10:50 AM
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Joined: Jan 2003
Posts: 21,065
Niles , Ohio
therocks
oh wait.but hey.lets see.oh yeah.
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oh wait.but hey.lets see.oh yeah.
Joined: Jan 2003
Posts: 21,065
Niles , Ohio
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WE just put mt semi ported over sized valves 516s on my kids 62 300.The 413 heads are super restrictive.They had 2.02 and like 1.60 exhausts.He still runs 13.6.He dropped maybe .05 changing them.He is spinning more off the line and the cam is holding it back on the top end.I figured they would be good for at least 3 tenths difference.Change one thing you have to change another.With the old heads it was done at like 5500.Now it wants to pull but the cam just wont let it.Rocky
Chrysler Firepower
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