Moparts

will aluminum heads make a difference on my motor?

Posted By: hunterstroble

will aluminum heads make a difference on my motor? - 01/19/10 11:15 PM

I have a 440 in my challenger, i don't race it anymore, just cruise with the kid. I have a 440 with 11-1 compression, .505in .505 exh 290 duration isky solid lifter cam, 1.5.1 roller rockers, 452 heads with 2.14 and 1.81 stainless valves, bowl ported and other port work and a three angle valve grind. An m1 single plane intake and 850 holley with a proform hp center body. My question is will I gain anything with a set of eddy or 440 source heads. I don't want to increase my cam or carb because I like the drivabilty of the componation. Thanks.
Posted By: RBSat66

Re: will aluminum heads make a difference on my motor? - 01/19/10 11:25 PM

It is my understanding that by going to aluminum heads the motor will gain in performance if the heads you have haven't been ported and also will take a point off the compression providing they have the same size combustion chambers. You don't actually lose compression it just tricks the motor into thinking it is 10/1 instead of 11/1
Posted By: AndyF

Re: will aluminum heads make a difference on my motor? - 01/19/10 11:32 PM

You'll probably notice a little more power and you might also notice the 40+ lbs off the nose of the car.
Posted By: dOoC

Re: will aluminum heads make a difference on my motor? - 01/19/10 11:40 PM

On the small chambered Eddy heads .. you should notice more of a diff than with the larger chambered ones.

What are you using for fuel with the 452 head combo?
Posted By: WILD BILL

Re: will aluminum heads make a difference on my motor? - 01/19/10 11:42 PM

I noticed a big difference when I bolted on my Edy's OOTB but my old Iron heads were untouched.
Posted By: hunterstroble

Re: will aluminum heads make a difference on my motor? - 01/19/10 11:51 PM

I use 92 octane at 36 degrees total timing, no detonation, i swapped to the thim sheet metal gaskets last summer and there were no detonation marks either. I'm just wondering by swapping heads if there will be 1000 dollars difference.
Posted By: dOoC

Re: will aluminum heads make a difference on my motor? - 01/19/10 11:55 PM

92 octane with 11 to 1 compression ? ...... I would KEEP your combo and put those 1000 beans into something else !
Posted By: RapidRobert

Re: will aluminum heads make a difference on my motor? - 01/19/10 11:55 PM

Hypothetical Q: If a person replaced a set of 452's w a set of eddies and the chamber/port dimentions were IDENTICAL on each (1) what would be the difference in performance (if any) and (2) With the aluminum conducting heat faster would that be what would be making this difference (if there's a difference)? and (3) if the eng (w the 452's) was at the ping limit with his current choice of fuel (and his current CR) if the SCR was was raised (w NO other changes) would he be able to run the same octane w no pinging? and (4) if so would there be a gain in power (w the higher CR/alum heads (which'd be wicking away heat)?
Posted By: AndyF

Re: will aluminum heads make a difference on my motor? - 01/20/10 02:08 AM

Quote:

I use 92 octane at 36 degrees total timing, no detonation, i swapped to the thim sheet metal gaskets last summer and there were no detonation marks either. I'm just wondering by swapping heads if there will be 1000 dollars difference.



Depends how much money you have. If you're going hungry and the kids don't have shoes then spend the grand on something else. If you have a big toy budget then a set of Edelbrock heads is a logical investment. Better yet buy the Mopar version with the straight plugs so you don't have a hassle with the plug wires.
Posted By: hunterstroble

Re: will aluminum heads make a difference on my motor? - 01/20/10 02:50 AM

The 440 source stealth heads have straight plugs also.
Posted By: joewhite440

Re: will aluminum heads make a difference on my motor? - 01/20/10 03:42 AM

I have ran a lot of iron heads stock and with Major work on them on cars we have raced. With all the work you have done on your Iron heads you will not get $1000 worth of HP or ET with the EDDY's. I have Ran both.

440 source heads, (I have not ran). I have used the Mopar Heads but I think you would want a bigger cam with them. They have raised ports etc
and are more expensive.
If you did not have all the work done to your heads, yes it would be a good investment. You probably have $600 or more in your heads.
Positives:
Like others have said you will loose weight in your car and it should run cooler.
Posted By: StealthWedge67

Re: will aluminum heads make a difference on my motor? - 01/20/10 04:53 AM

Quote:

Hypothetical Q: If a person replaced a set of 452's w a set of eddies and the chamber/port dimentions were IDENTICAL on each (1) what would be the difference in performance (if any) and (2) With the aluminum conducting heat faster would that be what would be making this difference (if there's a difference)? and (3) if the eng (w the 452's) was at the ping limit with his current choice of fuel (and his current CR) if the SCR was was raised (w NO other changes) would he be able to run the same octane w no pinging? and (4) if so would there be a gain in power (w the higher CR/alum heads (which'd be wicking away heat)?



The following are just my somewhat educated opinions. I am not a professional engine builder, just a hobbyist. with that said, I'll take a swing at these Q's:

1) IF everything else was the identical, and only the material was in question: none, if anything the iron heads might offer a very slight horsepower advantage, but aluminum weighs less, so your car gets lighter. Advantage Aluminum.

2) The difference would be that just as aluminum dicipates the heat, it also dicipates energy (this is why its good when used at main caps). Since it dicipates energy at a slightly higher rate than iron, the iron heads would create more energy inside the cylinder, hence, slightly more HP. (emphasis on SLIGHTLY)

3) depends on how much you raise the compression. because of the same pricipals noted @ #2, you can use slightly more static compression with aluminum. with that said, If I was the OP, I'd opt for the Eddy large chamber heads to break even, or slightly lower my compression (11:1 is too much for pump gas in my book, even with aluminum heads)

4)more compression generally = more power. but again, at 11:1 on pump gas, I would'nt look to raise it.

Hope that helps, let me know if you dissagree.
Posted By: Classof70Chally

Re: will aluminum heads make a difference on my motor? - 01/20/10 05:31 AM

If you are really running 11 to 1 on 92 swill with iron heads you are either very good or very lucky. That cr is usually about where you start topping out with aluminum heads which is one reason (more cr capability) to go from iron to aluminum. I built my motor (Stealth heads) to be a true 10.0 to 1 cr. I wasn't going with a big cam and wanted a healthy street motor that can even run regular if it has to.
Posted By: hunterstroble

Re: will aluminum heads make a difference on my motor? - 01/20/10 06:48 AM

probobaly lucky, but my car runs really rich, my dad's car had the same combo before he went to a 500 and his did not ping either.
Posted By: DaytonaTurbo

Re: will aluminum heads make a difference on my motor? - 01/20/10 07:44 AM

Quote:

I'm just wondering by swapping heads if there will be 1000 dollars difference.



No. Your worked over stock heads probably don't leave much on the table compared to OOTB eddys or stealths. Now drop 2000 dollars on a set of CNC ported stealths that flow 310-320cfm and there you'll see some difference!
Posted By: DaytonaTurbo

Re: will aluminum heads make a difference on my motor? - 01/20/10 07:46 AM

Quote:

Hypothetical Q: If a person replaced a set of 452's w a set of eddies and the chamber/port dimentions were IDENTICAL on each (1) what would be the difference in performance (if any) and (2) With the aluminum conducting heat faster would that be what would be making this difference (if there's a difference)? and (3) if the eng (w the 452's) was at the ping limit with his current choice of fuel (and his current CR) if the SCR was was raised (w NO other changes) would he be able to run the same octane w no pinging? and (4) if so would there be a gain in power (w the higher CR/alum heads (which'd be wicking away heat)?



A while back someone on here posted a dyno comparasin from one of the hot rod mags of two chevy motors side by side. Built identically, identical heads except one was iron one was aluminum to test this alum vs iron theory. Results on the dyno, no difference between the two. So if you can up the SCR with the alum heads, it's only a win-win situation for you over the irons.
Posted By: Dodgem

Re: will aluminum heads make a difference on my motor? - 01/20/10 01:35 PM

This the cam
SOLID
.505 .028 290° 254° 108°
.505 .028 290° 254
this cam is big enough to help reduce cylinder pressure below 4000 so goes a long way to reducing ping with an iron head.
Not enough gain Edlebrock OOTB to spend $1450 IMHO and the Source heads will do nothing The source heads are a far inferior head to the Eddy OOTB they may come close CNC port to CNC port but still a Chinese crap shoot at best!!

Now if your were bracket racing the extra 2 3 tenths an OOTB eddy would give means a lot on the street you will not feel it or feel very little
Posted By: StealthWedge67

Re: will aluminum heads make a difference on my motor? - 01/20/10 03:59 PM

If you just don't like stuff manufactured by a Chinese person, thats your deal. But to say Stealth heads are crap is just plain stupid. They flow nearly exactly what an Eddy head does, Hundreds of guys right here on this site are using them with little or no trouble, and at $500 less than a pair of Eddy's, there is just no denying the fact that they are perhaps the best bang for buck available for a Mopar big block on the market today. Personally, from a guy with a family and a limited hot-rod budget..... "THANK YOU BRANDON!!!"
Posted By: 62maxwgn

Re: will aluminum heads make a difference on my motor? - 01/20/10 06:03 PM

From your first post,quote " i don't race it anymore, just cruise with the kid.".

My answer would be,why bother ?
Posted By: WILD BILL

Re: will aluminum heads make a difference on my motor? - 01/20/10 06:33 PM

GEnsrud, reread Dodgem's post. He didn't say they were crap. He said they were a "crap shoot"
Posted By: draginmopars

Re: will aluminum heads make a difference on my motor? - 01/20/10 06:40 PM

Quote:

GEnsrud, reread Dodgem's post. He didn't say they were crap. He said they were a "crap shoot"



Notice that he edited it... said Crap last time, then was changed
Posted By: draginmopars

Re: will aluminum heads make a difference on my motor? - 01/20/10 08:06 PM

for the last 2 years, I've beat the "crap" out of my engine (stealth heads)
nothing has came out yet if did fry 3rd gear, was the reason for pulling the eng/trans.

ported cast head= 7.51 et.
ported stealth head= 7.38
everything else the same with et streets and mufflers
Posted By: Dodgem

Re: will aluminum heads make a difference on my motor? - 01/20/10 08:44 PM

Quote:

Quote:

GEnsrud, reread Dodgem's post. He didn't say they were crap. He said they were a "crap shoot"



Notice that he edited it... said Crap last time, then was changed



No the edit wast to add this line
"Now if your were bracket racing the extra 2 3 tenths an OOTB eddy would give means a lot on the street you will not feel it or feel very little"
I have a set of 440 source in my garage. A friends! Absolutly will not flow OOTB what a eddy will No way near as nice a head as an eddie.
Guys who have flowed them 250 OOTB where eddies are 280 to 290 OOTB.
Both CNC they are close why can't people under stand that??
Better than a stock iron you bet!! I shop at walmart too sometimes you get what you pay for!!!
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