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440 Source Super Stealth heads

Budnicks,

The standard Stealth head comes OOTB 275-285 cfm. Certainly not enough flow for 725 HP. You must port the Stealth to get 725 HP.

I've never seen an AS CAST head that will make 725 HP. They all have to be ported to get that level of performance. Why buy another head, IF YOU ALREADY OWN Stealth heads and all you want is 725 HP? Just have the Stealth heads ported.

If you don't have any heads and you want more than 700 HP, don't start with the Stealth head, get a better head to start with and have it ported.

ANY AFTERMARKET ALUMINUM HEAD, THAT YOU ALREADY OWN, CAN BE MADE TO GO 700+ HP, ANY OF THEM! So you don't have to buy another head if that is your maximum goal.

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Jim, just for kicks, what do you think about the pro comp heads? Like these?

http://www.ebay.com/itm/190796320252?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2649

Never used them, but what I think I see is a chinese Victor. The flow tests I have seen, but never done personally, seem to say they don't flow as good OOTB as the Victor. Their ultimate potential is unknown to me at this time as I have never tested them. Like I said above though, I'm sure they will go 700+ HP. For crying out loud, we get 730+ HP from ported factory 906 heads.
 
Budnicks,

The standard Stealth head comes OOTB 275-285 cfm. Certainly not enough flow for 725 HP. You must port the Stealth to get 725 HP.

I've never seen an AS CAST head that will make 725 HP. They all have to be ported to get that level of performance. Why buy another head, IF YOU ALREADY OWN Stealth heads and all you want is 725 HP? Just have the Stealth heads ported.

If you don't have any heads and you want more than 700 HP, don't start with the Stealth head, get a better head to start with and have it ported.

ANY AFTERMARKET ALUMINUM HEAD, THAT YOU ALREADY OWN, CAN BE MADE TO GO 700+ HP, ANY OF THEM! So you don't have to buy another head if that is your maximum goal.

- - - Updated - - -



Never used them, but what I think I see is a chinese Victor. The flow tests I have seen, but never done personally, seem to say they don't flow as good OOTB as the Victor. Their ultimate potential is unknown to me at this time as I have never tested them. Like I said above though, I'm sure they will go 700+ HP. For crying out loud, we get 730+ HP from ported factory 906 heads.

I appreciate all the knowledge this site has to offer. Being a beginner level engine mechanic as myself, I have profited a lot from these topics.

That being said, since I'm trying to understand the pro's of cylinder head swaps. So the advantages of aluminum is only weight and possibly quench( if close chambered irons aren't available ). So if porting is necessary for flow, then any head will work?
 
The other advantage aluminum has is that your head porter will charge a good bit less because aluminum is much easier on his tools.
 
Jim, thanks very much for taking the time to answer all my dumbass questions. Since you do this for a living, I really appreciate it.
 
Budnicks,

The standard Stealth head comes OOTB 275-285 cfm. Certainly not enough flow for 725 HP. You must port the Stealth to get 725 HP.

I've never seen an AS CAST head that will make 725 HP. They all have to be ported to get that level of performance. Why buy another head, IF YOU ALREADY OWN Stealth heads and all you want is 725 HP? Just have the Stealth heads ported.

If you don't have any heads and you want more than 700 HP, don't start with the Stealth head, get a better head to start with and have it ported.

ANY AFTERMARKET ALUMINUM HEAD, THAT YOU ALREADY OWN, CAN BE MADE TO GO 700+ HP, ANY OF THEM! So you don't have to buy another head if that is your maximum goal.

.

Thanks IQ52, as you probably well know, I knew that already... I just wanted the clarification for anyone else, because the way I read the earlier post, was a little misleading {probably just me, being me...LOL}... as always thanks for all your help & knowledge & sharing it with all of us...
 
I appreciate all the knowledge this site has to offer. Being a beginner level engine mechanic as myself, I have profited a lot from these topics.

That being said, since I'm trying to understand the pro's of cylinder head swaps. So the advantages of aluminum is only weight and possibly quench( if close chambered irons aren't available ). So if porting is necessary for flow, then any head will work?

In my original post I limited horsepower considerations to around 700-725 HP.

All cylinder heads will reach a limit at some point. The ported factory iron heads reach their flow limit sooner. Ported aftermarket aluminum heads like the RPM and the Stealth have a greater horsepower potential than the factory iron. The heads like the Indy EZ, 440-1, Edelbrock Victor, B1-BS, Pro Comp have more potential than the RPM or Stealth.

Examples:

With the ported factory 906 the best we've seen so far is right at 750 HP with 500 ci, with 451 ci and the Edelbrock RPM....787 HP and with 500 ci and the Edelbrock Victor we've gotten 928 HP. All these engines were normally aspirated.
 
IQ,

You guys use a 45 or 50 degree intake seat? Also, you usually do a backcut on the exhaust side?
 
Just curious have you ever played around with a set of the old Bulldog heads?
 
thanx a ton for dropping all the know how iq.this thread is very informative.
 
IQ52,
Do you find that performance has been higher on the Victor style "Edelbrock or ProComp" heads for each CFM of flow due to the Heart shaped chambers and CC's?
In other-words, CFM to CFM comparison does the Victor out perform in HP/Tq over the other older style "D" shaped chambered heads?
 
IQ,

You guys use a 45 or 50 degree intake seat? Also, you usually do a backcut on the exhaust side?

I've never tested with a 50. Regularly.

Just curious have you ever played around with a set of the old Bulldog heads?

Nope

IQ52,
Do you find that performance has been higher on the Victor style "Edelbrock or ProComp" heads for each CFM of flow due to the Heart shaped chambers and CC's?
In other-words, CFM to CFM comparison does the Victor out perform in HP/Tq over the other older style "D" shaped chambered heads?

Never done a back to back comparison. Can you imagine how diffiicult it would be to balance the flows at each lift, on the two different styles of ports, so that you could get an accurate comparison? If you think that flows at lower lifts don't effect peak horsepower output, reconsider. With the Edelbrock RPM head, we have made 2.31 HP/CFM at peak flow and the Victor has done 2.54 HP/CFM......but......suprise.......the Victor was modified to a D combustion chamber shape. The engines were different cubic inch sizes with different cams and intakes so even then we didn't have a real comparison.

Hey, I guess that blows the heck outta the old standby 2 HP/CFM.
 
I've never tested with a 50. Regularly.



Nope



Never done a back to back comparison. Can you imagine how diffiicult it would be to balance the flows at each lift, on the two different styles of ports, so that you could get an accurate comparison? If you think that flows at lower lifts don't effect peak horsepower output, reconsider. With the Edelbrock RPM head, we have made 2.31 HP/CFM at peak flow and the Victor has done 2.54 HP/CFM......but......suprise.......the Victor was modified to a D combustion chamber shape. The engines were different cubic inch sizes with different cams and intakes so even then we didn't have a real comparison.

Hey, I guess that blows the heck outta the old standby 2 HP/CFM.

Very interesting.....
What lead you to cut the chamber out to a D shape?
Was it a flow #'s based decision? Did they perform better bolted to an engine (before/after) scenario?

Thanks for all your shared findings!
 
Very interesting.....
What lead you to cut the chamber out to a D shape?
Was it a flow #'s based decision? Did they perform better bolted to an engine (before/after) scenario?

Thanks for all your shared findings!

If I remember correctly, it went something like this, FOURTEEN AND ONE HALF TO ONE COMPRESSION!!!! I DON'T WANT FOURTEEN AND ONE HALF TO ONE COMPRESSION!!!!
 
If I remember correctly, it went something like this, FOURTEEN AND ONE HALF TO ONE COMPRESSION!!!! I DON'T WANT FOURTEEN AND ONE HALF TO ONE COMPRESSION!!!!

lol that is classic....totally been there (you decked the block HOW MUCH???)
 
If I remember correctly, it went something like this, FOURTEEN AND ONE HALF TO ONE COMPRESSION!!!! I DON'T WANT FOURTEEN AND ONE HALF TO ONE COMPRESSION!!!!

LaRoy Engines {Jim & Cody} out of Challis Idaho is the place to go... IQ52; I LMFAO that's too funny ... WOW 2.31hp/per-cfm let alone 2.54hp/per-cfm of flow is freaken' great for a B/RB wedge head... What bore size was that with ??, what exhaust/header tubing size, was that with ??, what type piston flat top or domed ?? {just curious} not too long ago, wasn't the old std. use to be like 2.06hp/per-cfm for a professionally ported head ??, some old guy told me that...
 
LaRoy Engines {Jim & Cody} out of Challis Idaho is the place to go... IQ52; I LMFAO that's too funny ... WOW 2.31hp/per-cfm let alone 2.54hp/per-cfm of flow is freaken' great for a B/RB wedge head... What bore size was that with ??, what exhaust/header tubing size, was that with ??, what type piston flat top or domed ?? {just curious} not too long ago, wasn't the old std. use to be like 2.06hp/per-cfm for a professionally ported head ??, some old guy told me that...

2.06 hp/cfm is for the average build, we don't do average builds for ourselves.

RPM head: 451 ci, 4.375 bore, 11.7:1, pump gas, flat top, Hooker 5209-1HKR headers. 1.745 HP/CI

Victor head: 500 ci, 4.375 bore, 13.7:1, E85, domed piston, custom headers by Cody LaRoy 2" X 2-1/8" X 3.5" step header. 1.856 HP/CI
 
2.06 hp/cfm is for the average build, we don't do average builds for ourselves.

RPM head: 451 ci, 4.375 bore, 11.7:1, pump gas, flat top, Hooker 5209-1HKR headers. 1.745 HP/CI

Victor head: 500 ci, 4.375 bore, 13.7:1, E85, domed piston, custom headers by Cody LaRoy 2" X 2-1/8" X 3.5" step header. 1.856 HP/CI

Thanks for sharing... some nice build there 790hp & 928hp great #'s for wedge motors...
 
Yeah Rob, I very much like the standard Stealth head. As I've said before, if you already own a Stealth head and want up to 725 HP normally aspirated, it is cheaper to put new intake seats and valves in the Stealth head and port it, than buy another aftermarket head and port it to get the horsepower. I don't know of another OOTB after market head, unless it is already CNCd, that will make 725 HP without porting it,

This is good info, I have been using the 2nd gen stealth heads and they seem fine out of the box and as you mentioned, like myself the novice and for the street it works great and if I decide to try to squeeze more hp out of them just do some work and it's done. Funny thing is this is how they are advertised on 440source.com one of the reasons i chose them besides price.
 
440.jpgcnc ported by Bob at MCH
 
Jim do you know how accurate you flow bench is ? I only ask because I hear some head porters say no two benches give the same numbers. I am not saying I dont believe you but it would be nice to see what they read on another flow bench. Ron
 
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