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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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Lincoln Nebraska
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RapidRobert Offline
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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
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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Manitoba, Canada
DaytonaTurbo Offline
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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...

Re: Iron heads vs. Stealths [Re: ireland383] #440887
08/19/09 12:00 AM
08/19/09 12:00 AM
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Posts: 2,825
Sk. Canada
RemCharger Offline
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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?

Re: Iron heads vs. Stealths [Re: ireland383] #440888
08/19/09 03:17 AM
08/19/09 03:17 AM
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Aurora, Colorado
451Mopar Offline
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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.

Re: Iron heads vs. Stealths [Re: ireland383] #440889
08/19/09 03:31 AM
08/19/09 03:31 AM
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Gainesville,FL
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goldmember Offline
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"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.

Re: Iron heads vs. Stealths [Re: goldmember] #440890
08/19/09 04:56 AM
08/19/09 04:56 AM
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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.

Re: Iron heads vs. Stealths [Re: 451Mopar] #440891
08/19/09 06:47 AM
08/19/09 06:47 AM
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Posts: 843
Suffolk,VA
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ireland383 Offline OP
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The 8519's were used. I should know results of the leakdown test tomorrow.

Re: Iron heads vs. Stealths [Re: RemCharger] #440892
08/19/09 07:04 AM
08/19/09 07:04 AM
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Posts: 843
Suffolk,VA
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ireland383 Offline OP
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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?

Re: Iron heads vs. Stealths [Re: DaytonaTurbo] #440893
08/19/09 10:50 AM
08/19/09 10:50 AM
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Posts: 21,050
Niles , Ohio
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therocks Offline
oh wait.but hey.lets see.oh yeah.
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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


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Re: Iron heads vs. Stealths [Re: ireland383] #440894
08/21/09 01:31 PM
08/21/09 01:31 PM
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JOPLIN MO 64804
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Depends on cc's of both heads for comparison and port air flow of both sets for comparison,the 346's probably have less cc's than the stealths[ combustion chamber]thus more comp, and smaller chambers, thus more velocity than the stealths,in out of the box perf, mil the stealths and play with the timing,change carb jetting, the stealths have alot more potential than the 346's, but the 346's probably outperform the stealths in stock form,I have seen some pretty mean cast iron heads run in the low 10's on 440's....

Re: Iron heads vs. Stealths [Re: RBDART1] #440895
08/23/09 07:23 PM
08/23/09 07:23 PM
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Posts: 843
Suffolk,VA
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ireland383 Offline OP
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Being both heads are at 84 cc's. I can't have to much shaved off because of comp. ratio with the domed pistons. I know not many people used that cam 275DEH, but I think that is a big part of the problem with running the stealths.

Re: Iron heads vs. Stealths [Re: ireland383] #440896
08/23/09 07:51 PM
08/23/09 07:51 PM
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Posts: 531
SE Michigan
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That cam isn't much bigger than a stock cam. If you had a much larger cam, you would have noticed a big diference with the alloy heads. As it is the 346's can flow as much air as that cam will allow.

Re: Iron heads vs. Stealths [Re: farmington] #440897
08/23/09 07:54 PM
08/23/09 07:54 PM
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Posts: 74,905
U.S.S.A.
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