my friend says iron heads are better
#1
Staging Lane
Thread Starter
Join Date: Dec 2003
Location: Los Angeles
Posts: 87
Likes: 0
Received 0 Likes
on
0 Posts
my friend says iron heads are better
My mustang friend was telling me that he wanted to get iron heads for his 5.0 buildup because they make more power. He said that if you take iron heads with the same casting as aluminum, the iron heads would dyno higher on the same engine.
I think he's full of **** on that and I told him he needs to get aluminum heads for his 5.0. What do the experts say?
I think he's full of **** on that and I told him he needs to get aluminum heads for his 5.0. What do the experts say?
#2
TECH Resident
Join Date: Jul 2003
Location: Marysville, OH
Posts: 834
Likes: 0
Received 0 Likes
on
0 Posts
Experts say your friend is a dumbass.
Kick him in the nuts the next time you see him, there is really no merit for his argument. Ask him if they are so powerfull why ford and gm use aluminum on there performance engines.
Kick him in the nuts the next time you see him, there is really no merit for his argument. Ask him if they are so powerfull why ford and gm use aluminum on there performance engines.
#3
Banned
Join Date: Sep 2002
Location: Azle/Saginaw, Tx
Posts: 5,581
Likes: 0
Received 0 Likes
on
0 Posts
lol at BLK, as soon as i saw the title of this thread my first thought was to type in "kick your friend in the nutts"....hahaha, yeah, beat him with a stick or heavy object of some sort. the experts say, hmmmm, do a search on nascar, or NHRA top fuel, pro stock etc....those are the extremes of their types of engines and ALL....use aluminum heads.
#4
TECH Junkie
Join Date: Nov 2001
Location: Los Angeles
Posts: 3,604
Likes: 0
Received 0 Likes
on
0 Posts
Quite a few people agree that iron heads will make a tad more power than aluminum. I've not seen it for myself, so I'll just have to take their word for it. I think it has to do with heat transfer.
Nascar, and others may use aluminum for the weight savings on the front of the car, and to keep the center of gravity lower (the heads are pretty high up on the car).
Anyway, the point is, I beleive your friend is correct and his nuts shall go unkicked.
Oh, sloverado, I saw some tan jeep grand cherokee thing on I-35 a few weeks ago with "SLOVERADO" written on the back. I assume that was you headed to the SBSO.
Nascar, and others may use aluminum for the weight savings on the front of the car, and to keep the center of gravity lower (the heads are pretty high up on the car).
Anyway, the point is, I beleive your friend is correct and his nuts shall go unkicked.
Oh, sloverado, I saw some tan jeep grand cherokee thing on I-35 a few weeks ago with "SLOVERADO" written on the back. I assume that was you headed to the SBSO.
#5
Banned
Join Date: Sep 2002
Location: Azle/Saginaw, Tx
Posts: 5,581
Likes: 0
Received 0 Likes
on
0 Posts
SLOWVERADO, that was me...what were you in man? i didn't try to get ya to race or anything did i? if nascar engine builders thought for an instant of a second that iron heads would make more power they would have them on the cars, those guys spend houndreds of thousands of dollars annualy if not more in head research for just 5 or 6 horsepower...warren johnson has over 5k sets of alum. big block heads he works with porting, flowing etc to get the best 10-20 at a time to use for his pro stock engines. if iron made more power in ANY way i would have to believe the real pros would be using them.
Last edited by Slowverado; 03-28-2004 at 01:40 AM.
#6
On The Tree
Join Date: Jul 2003
Location: San Jose, CA
Posts: 166
Likes: 0
Received 0 Likes
on
0 Posts
You friend is correct... with the SAME casting an Iron head will make SLIGHTLY more power on a DYNO. However, seeking out Iron heads for a performance car is a big waste for two reasons.
1) Generally the best head designs are all cast in Aluminum.
2) The small HP gain you get from the iron heads does NOT compensate for the weight penalty you receive over using aluminum.
1) Generally the best head designs are all cast in Aluminum.
2) The small HP gain you get from the iron heads does NOT compensate for the weight penalty you receive over using aluminum.
#7
TECH Junkie
Join Date: Nov 2001
Location: Los Angeles
Posts: 3,604
Likes: 0
Received 0 Likes
on
0 Posts
Slow, I was in a pewter transam, between Austin and Waco heading south to Austin. Yall were looking at the car (my GF's) as you went past. No racing was occuring
As for the rest of the stuff, do a little searching and I bet you'll come across tons of places that have discussed this very topic. Having big chunks of iron on a motor are not good for racing, especially when they are 3 feet off the ground. Acceleration is still dependant on weight...however, the question was which makes more power (not which one would make a car go faster), and that would be the iron.
As for the rest of the stuff, do a little searching and I bet you'll come across tons of places that have discussed this very topic. Having big chunks of iron on a motor are not good for racing, especially when they are 3 feet off the ground. Acceleration is still dependant on weight...however, the question was which makes more power (not which one would make a car go faster), and that would be the iron.
Trending Topics
#8
Banned
Join Date: Sep 2002
Location: Azle/Saginaw, Tx
Posts: 5,581
Likes: 0
Received 0 Likes
on
0 Posts
on a case by case basis i guess...i agree about more power...i was definatly thinking about quicker...
if your girlfriend is blonde and was riding in the passenger seat of the TA then i remember seeing her...i was driving....we saw several car loads of girls on 35 south man, it was great. only regret is not driving back up to Austin saturday night for the Ragweed concert.
if your girlfriend is blonde and was riding in the passenger seat of the TA then i remember seeing her...i was driving....we saw several car loads of girls on 35 south man, it was great. only regret is not driving back up to Austin saturday night for the Ragweed concert.
#12
TECH Senior Member
iTrader: (4)
All things equal the iron head will make a little more power due to retained heat. Since the aluminum head transfers heat quicker and is less prone to retain heat, the aluminum heat will tolerate a little more compression than the iron without detonation. Depending on the head in question usually an aluminum one will tolerate ~1/2 to 1 point more compression than a similar cast iron one will. Amazingly adding this ~ 1/2 to 1 point of compression helps close the gap between what the iron head and the aluminum were making powerwise. This sort of makes sense because in the end it's all heat transfer.
All things equal the cast iron head will make more. With the bump in compression the aluminum head (with everything else equal) will be very close in the typical applicaiton assuming you push both heads as close to the edge as possible without detonation. As mentioned above the weight savings tips the scales toward the aluminum head.
That's my understanding maybe someone else will clarify better.
All things equal the cast iron head will make more. With the bump in compression the aluminum head (with everything else equal) will be very close in the typical applicaiton assuming you push both heads as close to the edge as possible without detonation. As mentioned above the weight savings tips the scales toward the aluminum head.
That's my understanding maybe someone else will clarify better.
#15
Launching!
iTrader: (1)
Join Date: Feb 2004
Location: Minnesota
Posts: 296
Likes: 0
Received 0 Likes
on
0 Posts
ok guys here it is. HEAT IS POWER!!! the more heat you make the more power you make. Saying that, the more heat you retain in the chamber, the more power (work) can be made. DaleMX has it, why not coat the aluminum head to retain the heat. The thing you have to remember when you do this is if you don't go up in octane, there could be major detonation.
Every fuel has its own self igniting point. If you keep the chamber temp below this temp, you will be fine, if not, well uh, you know what happens.
Hope this clearifys things.
Every fuel has its own self igniting point. If you keep the chamber temp below this temp, you will be fine, if not, well uh, you know what happens.
Hope this clearifys things.
#17
Launching!
iTrader: (1)
Join Date: Feb 2004
Location: Minnesota
Posts: 296
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by 1QWIKZ
i thought iron heads made more power because you can run more timing on them.
So in saying an Iron head takes more timing is not true because if a comparision was made where both heads flowed the same amount of air and had the exact same compression ratio, the aluminum head would actually take more timing because it is "sucking" more heat out of the chamber.
IMO, I would always go with the aluminum heads cause of the weight savings. 60 - 80 lbs, on the top of the engine makes for a bad roll center and also just a plain heavier car. I would just add compression to compensate for the heat loss.
Now if you were racing in a class that has a compression ratio limit, that is a different story. Usually when they let you run aluminum heads, they make you add weight. I would find out where they would let you put the weight and make a decision based on that.
I agree with the guys who are saying that the power from the cast is offset by the weight, and that aluminum is used in racing because of the ease of porting and fixing.
#18
Take 2 identical heads, one iron one aluminum. 2 identical motors, both running the same compression, timing and neither is detonating. The iron head will make more power. How much, I can't say.
The aluminum head with a coated combustion chamber is the best of all worlds. This is taking into account weight, ease of porting and repair, and it will have better heat retention than bare aluminum. Racers who know which cylinders run leaner and which run richer, will have the chambers on their aluminum heads coated accordingly. If you have one cylinder running leaner, ie: hotter than they don't coat that chamber, and vice versa. That helps them balance out their EGTs, making more power and a happier engine.
The aluminum head with a coated combustion chamber is the best of all worlds. This is taking into account weight, ease of porting and repair, and it will have better heat retention than bare aluminum. Racers who know which cylinders run leaner and which run richer, will have the chambers on their aluminum heads coated accordingly. If you have one cylinder running leaner, ie: hotter than they don't coat that chamber, and vice versa. That helps them balance out their EGTs, making more power and a happier engine.
#19
And there's another factor in favor of iron heads: I run 1700 cfm and a 100 shot, and I am currently torquing my 9/16" head studs to 140 lbs., which tends to bow the aluminum LS1 head a bit. If I could find CI heads that flow 320/350 cfm, I would buy them because they are stronger.