heads stealth vs edelbrock

[68gtx]

sorry if this has been beaten to death , but would like some opions, gonna build a motor , 440 stroker, street motor , but wanna get all i can out of it being sensible, question is stealth or edelbrock, stealth looks more sleeperish, but do they compare??? , the e streets vs rpms , according to the specs they flow the same numbers???? if i can add to this , what is a safe compression ratio that can be run with pump fuel and alumiunm heads? from what i have read they say a full point higher with aluminum, and they say 10.5 to1 but would 10.8 be ok?? i know someone has done this math...

thanks in advance

 

[Kern Dog]

Take this advice from a guy that has dealt with detonation problems for several years:
If you are interested in having a well mannered street car that can run in 100 degree weather without knocking to death, you will need to limit the compression ratio to 10.0 to one or less. There are several guys that may tell you that you can run 12 to one on iron heads as long as you use the right cam. My understanding is that this "right cam" is often one that is much more radical than you might want in a street car.
It is very important that your engine is built with a matching set of components. By this I mean you wouldn't want to use an 8.0 compression with a .750 lift roller cam. You wouldn't put a tunnel ram with 1050 Dominator carburetors on a stock 440.
Personally, I have learned from several mistakes that I have made. If I build another stroked 440, this is how I'd do it:
440 block of any year. Bored only to the point where the cylinders are cleaned up, usually .030. ZERO deck the block.
4.15 crank, Manley 6.76 H beam rods.
Reverse Dome dished pistons with quench pad. This will allow lower compression while allowing adequate quench.
Edelbrock E street heads with 75 cc chambers, .039 Fel Pro head gasket.
Cam? Thats a tough one. LOTS of good ones out there. I'm told that cubic inches really eat up the duration. This means that a cam that lopes and sounds racy in a 383 may sound smooth in a 500 inch engine. I've used the MP 509 cam , the Comp XE285HL and the Lunati 316/326 solid. All 3 had a slight lope and idled pretty good.
The most important piece of advice I can give is this: Building an engine with a compression ratio that requires race gas or the highest pump premium means that you always need to keep the car in tip-top tune. Forget letting your guard down. If the weather gets hot, you somehow get a tank of bad gas or you let the car sit for a few months, you will probably have detonation.
I am now a believer of leaving a little more "wiggle" room in the build. Whatever small HP gains you might see by running close to 11.0 to one compression is not worth the risk of detonation. In my case, I've had to retard my spark timing to run my car at the approx 11 to one ratio. Retarded timing costs power. I'm reducing my compression ratio to allow my engine to run right on the 91 octane gas that were are limited to here in CA. The lower ratio will allow me to advance my ignition timing. This will result in MORE power than I had with higher compression and less timing.

- - - Updated - - -

I just found this:

http://store.440source.com/Platinum-Series-Pistons-4350-24-Dished/productinfo/5080/

This piston along with the 75 cc Edelbrock E-Street head gives you a 9.94 ratio.

 

[HT413]

You might want to read through this thread.

http://www.forbbodiesonly.com/moparforum/showthread.php?58687-Iron-head-test-starting-on-78-440

Not suggesting you copy his build at all, but read through his observations and thoughts on compression vs flow. The guy is a master mopar engine builder that competes in the big national contests. According to him, go conservative on compression ratio and still build massive power (what I consider massive power, anyway) with, as Greg says above, a well matched combo.

According to Jim (iq52), it's all about flow flow flow. Another thing to research is quench, which is a key concept that Greg is alluding to. I could tell you what I've read, but I don't want to get in over my head, all I've done is read about it.

 

[IQ52]

None of the stock replacement aluminum cylinder heads you mentioned have an advantage in horsepower over the others when properly prepared (and they all must be prepared).

#1 CHOOSE THE FUEL YOU WANT TO USE,

#2 engine characteristics (cam),

#3 set the compression ratio and make the cylinder heads flow to the horsepower level.

Design the engine internal strength around the power level you intend to run.

 

[GTX MATT]

Do you want straight or angled plugs? I think angled plugs are a huge pain in the you know what so I went with the Stealths.

 

[Meep-Meep]

And I'll add that with a big inch motor you can do more with less. Meaning choose the correct cam in proportion to the larger displacement but pay attention to the lobe separation angle. Too short like a 108 degree will tend to have more overlap and that does not make for a good street cam - unless you want to drive with your foot to the floor near max RPM most of the time. Choose a cam in the 112 - 114 LSA for good idle vacuum and overall wide torque band. The shorter the LSA the higher the peak torque, but if you are not near peak why have it? Cam RPM range also goes hand in hand with gear ratio and vehicle usage so pay attention to that as well. For me I like to tune for 1/4 mile performance, so I will gear accordingly. If I'm building a dual purpose car I'll pick a 3.55 gear and a cam that plays nicely in the 1500 - 5500 RPM range. With a 500" 440 based stroker think 500 Cad engine (i.e locomotive).

 

[747mopar]

"Well" Meep Meep pretty much said what I'd say. To many people build motors just to be badass and don't think the whole package threw and end up with a lousy car to drive "it all has to match". Now for me (regarding which head) I only need to know one thing "Stealth's are made of Chinesium" (a known inferior material) and I will not buy Chinesium parts for my car especially motor. All of the dyno test I've seen have the Eddies topping the Stealth's in stock form but agree with IQ that you should have them gone threw by a shop (I've seen a few new or reman heads that weren't fit to be run). I'd have your shop order them bare and let them put them together that way you'll have the proper springs and the piece of mind that it's right.

 

[bigmanjbmopar]

I have the stealths all stock nothing done to them with using the 1.5 ratio set up comp cams springs ect. I wanted a street car with god low end so I went with .030 over bore 493 stroker kit -24 cc dished pistons for pump gas. Runs great on 91 oct. No ping at all with total timing @ 35. Mild cam. Stock 3:55 8-3/4 rear end. 727 trans. 850 qft dbl pmp other than the typical cold blooded mopar it runs good.

 

[Meep-Meep]

Or you can send a set of iron heads to IQ and he can work them over for about the same price as a set of stealths. The advantage here is you won't have to fix them before you put them on.

 

[68gtx]

im kinda leaning towards the stealths because they would be more stealth, wanna paint them and make it look as stock as possible, which i think would be not possible with the edelbrocks..this is gonna be a pure street motor, will never see the track

 

[bigmanjbmopar]

I run the stealth out of the box, they are fine. All stock mount locations is nice. I built a 493 stroker with -24cc dished pistons to get down to 9:6-1 compression. Works great on 89 & 91 gas. Did not have to change or fix anything on the heads just check the push rod holes for rub. There has been a big stink since those heads came out because the aluminum is cast by a Chinese company and then sent to 440source for clean up and flow testing, some just can't get past the fact that you can get good aluminum stock version heads for half the cost of others and includes valves, guides, springs and retainers. For $995 you can't go wrong it's been 2 years for mine and not one problem up to 6k on a few occasions. Best part is if you want more out of the heads just un bolt and take them down to a shop and get another 100 hp. Good luck let us know how it turns out. You can always pm me if you want more info.

 

[Kern Dog]

Best part is if you want more out of the heads just un bolt and take them down to a shop and get another 100 hp. QUOTE]

How bad would these heads have to be to leave 100 HP worth of improvements on the table ???
I'm no head porting guru, but I'm sure that your estimate is waaaaaay optimistic!

 

[BeastlyBirdie]

Because you are matching the port flow to the cam. In other words, if the heads flow great at .600 lift, but your cam only sticks up at .500, you will actually make less power. Also, increased/better flow at lower lifts is, again, more useable power. Not sure on 100 hp gain, haven't heard that. Imo, I'd ditch the source valves and get better ones, 5 angle job, etc.
In a street engine, I generally run rings and piston clearance loose, too tight leads to friction, leading to detonation and a host of other issues...

 

[cdr]

i have the super stealth's,out of the box they flow around the 550 hp mark,,after my port work they flow in the 690 hp range,that is if EVERYTHING else is done correct .

 

[bigmanjbmopar]

Best part is if you want more out of the heads just un bolt and take them down to a shop and get another 100 hp. QUOTE]

How bad would these heads have to be to leave 100 HP worth of improvements on the table ???
I'm no head porting guru, but I'm sure that your estimate is waaaaaay optimistic!

Why hey would that mean they are bad?(proving my point some just can stand it) lol.

right from 440sources site
"Capable of an easy 550 horsepower out of the box (when used with our 500+ inch stroker kits) these have the potential to make 650-700+ horsepower with port work."


my math says 550 - 650 = 100 I was was being conservative so not to give unrealistic expectations lmao.


bottom line they are a good value and use comp cams parts a good stock replacement for better technology and lighter weight for a street car. Love it or hate it, if your not racing than these are a great deal, and when you do want to take it to the next level they are ready with just a little work or a lot depending on what you want but at least you already have them and do not have to spend $3000 for another worked set.

 

[747mopar]

I run the stealth out of the box, they are fine. All stock mount locations is nice. I built a 493 stroker with -24cc dished pistons to get down to 9:6-1 compression. Works great on 89 & 91 gas. Did not have to change or fix anything on the heads just check the push rod holes for rub. There has been a big stink since those heads came out because the aluminum is cast by a Chinese company and then sent to 440source for clean up and flow testing, some just can't get past the fact that you can get good aluminum stock version heads for half the cost of others and includes valves, guides, springs and retainers. For $995 you can't go wrong it's been 2 years for mine and not one problem up to 6k on a few occasions. Best part is if you want more out of the heads just un bolt and take them down to a shop and get another 100 hp. Good luck let us know how it turns out. You can always pm me if you want more info.

Nope, don't doubt it a bit as a matter of fact I've seen allot of dyno test showing nothing but that they are good heads. Now to correct your statement "some of us just won't buy Chinese parts plain and simple", I personally hate the Chinese Gov for they're constant cheating of the trade agreements and the fact that if I can use my money supporting those companies willing to stick it out to keep it in the states then that's what I'm gonna do. It's a pro American thing "that's all". Sorry for the political rant but just wanted to make sure you know where I'm coming from. Now here's a fact, I spent $900.00 on my 452's getting them completely rebuilt, guides, Ferra valves, valve job, surfacing, springs the works then ported them myself and have almost identical flow numbers to the Stealth's "for another $100.00 I could have had brand new aluminum heads" stupid? stubborn "definitely". As you were fella's

 

[IQ52]

Best part is if you want more out of the heads just un bolt and take them down to a shop and get another 100 hp. QUOTE]

How bad would these heads have to be to leave 100 HP worth of improvements on the table ???
I'm no head porting guru, but I'm sure that your estimate is waaaaaay optimistic!

I hope this doesn't turn into a long story, but it might.

First, the Stealth can be ported to the same level as the RPM, we've proven it again and again.

As to 100 HP worth of improvements, hmm.

We just had the good fortune to dyno test a customer built 499 wedge with our cleaned up Stealths. These were the best flowing OOTB Stealths I've ever tested.

Lift....................OOTB................Cleaned up

.100.................73/58...................75/69
.200...............143/117...............150/133
.300...............203/156...............211/176
.400...............247/184...............254/217
.500...............270/205...............285/234
.600...............283/221...............295/262
.700...............290/229...............297/280

The 499 was 11.5:1 and equiped with a MP 590, Torker II and 750 cfm 4150.

RPM............TQ/HP

3000.........481/275
3200.........508/310
3400.........546/354
3600.........560/384
3800.........559/404
4000.........552/420
4200.........544/435
4400.........535/448
4600.........543/476
4800.........560/512
5000.........558/531
5200.........545/539
5400.........532/547
5600.........517/552
5800.........495/547

Not exactly a direct comparison but we built a 496 with 10.5:1 solid street roller, Torker II, 950 cfm 4150 and our RPM heads flowing 305 cfm @ .600".

RPM ............TQ/HP

3600..........612/419
3800..........623/451
4000..........625/476
4200..........627/502
4400..........633/531
4600..........634/555
4800..........631/577
5000..........625/595
5200..........613/607
5400..........596/613
5600..........578/617
5800..........563/622 Okay, there is 70 HP

And a fully ported RPM set, flowing 340+ cfm @ .750" on an 11.7:1 451 stroker, Indy single plane, 1140 cfm Dominator, serious solid roller and 91 octane pump gas.

RPM.............TQ/HP

4000..........535/407
4200..........537/427
4400..........542/454
4600..........552/483
4800..........557/509
5000..........570/543
5200..........569/564
5400..........564/580
5600..........573/611
5800..........587/648
6000..........594/679
6200..........599/707
6400..........585/713
6600..........579/727
6800..........575/744
7000..........567/756
7200..........574/787

Nope, you can't get another 100 HP.

It looks more like 235 HP.