aftermarket CAST IRON heads?
- Thread starter 65notch
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brianj5600
Active Member
Wow! Someone needs to tell al the racers that aluminum heads are inferior. Top fuelers use aluminum heads. They make more hp with one cylinder than any sbf on this forum. The only reason a race engine would run cast iron heads is if rules require it. I'm guessing every car in 24hrs of Daytona and Le Mans run aluminum heads. Every NASCAR engine has aluminum heads. These people have to finish races and would not use aluminum if there were durability problems. Duramax diesels use aluminum heads, which suprised me. Corvettes have used aluminum heads for the last 20 or so years. Need I go on. Durability has not been a problem for years. If you want to save money that is one thing, but I have not seen an iron head that would flow close to what is offered in aluminum.
Hack
15 Year Member
It's one of those stupid subtle things that don't matter very much. If you consider thermodynamic theory the amount of energy you can get from a heat engine is based on the minimum versus maximum operating temperature. Another way to explain it is that gasses expand with higher temperature. Higher cylinder temperature = higher cylinder pressure = more horsepower (ambient air temperature is fixed). As stated before, you can compensate by increasing the compression ratio.jerry S said:
If you don't mind spending the money, aluminum is a good way to go - like I said before.
I agree that if you take precautions such as anti-seize on the plugs (which I would recommend with threads in any material) aluminum will work fine. You know that production cars would not be made with aluminum heads if aluminum couldn't do the job.
brianj5600 said:
aluminum heads have certain advantages, lighweight and easy repairability for two. also you can run higher compression ratios with aluminum heads. as far as top fuel, the ehads used on those engines are machined from a solid block of aluminum billit.
as far as aluminum flowing better than cast iron, that is a load of bravo sierra. as long as the port design is the same, iron and aluminum heads will flow the same, but iron heads, with the same compression ratio, will make abit more power. bump the compression as high as each head will allow on the same grade fuel, and the aluminum head will make abit more power due to a higher compression ratio.
to say one material is better than the other, is hogwash. both have their advantages and disadvantages, and both can be made to make the same power, and the same durability.
brianj5600
Active Member
The problem is that no one makes an iron heads with the same port design. The only good ones are "N" heads, but they use odd exhaust bolt patterns.rbohm said:
Route666
Active Member
Yeh I was going to reply again before and explain that the thread issue, warping issue, heat loss have been resolved or are negated by other benefits that aluminium bring, but I thought it would seem like more trying to get you to change your mind.
If you want iron heads, that's cool, it's different, and it's not all that big of a deal, except aluminium does weigh less, and it is hard to overcome just that advantage, in a performance sense. I would rather the best performing component, whether it be different or not, but that is me, and I (and everyone should) respect what you want, which is to have something a little different. Most people are into performance though, which is why everyone thinks you're crazy.
But if you look at the big picture, if you're REALLY that far into performance and not partially image, etc, then you wouldn't be using the classic Mustang to get the best performance, so even the performance guys on here are a little crazy.
If you want iron heads, that's cool, it's different, and it's not all that big of a deal, except aluminium does weigh less, and it is hard to overcome just that advantage, in a performance sense. I would rather the best performing component, whether it be different or not, but that is me, and I (and everyone should) respect what you want, which is to have something a little different. Most people are into performance though, which is why everyone thinks you're crazy.
But if you look at the big picture, if you're REALLY that far into performance and not partially image, etc, then you wouldn't be using the classic Mustang to get the best performance, so even the performance guys on here are a little crazy.
Route666 said:
im aware of the weight difference, and i wouldnt get iron heads for the entire fact that they are different....they are cheaper, i can get a pretty killer set for around 1000 bucks which seems pretty good to me.
if i can buy even better cast iron heads for less, could i make up for some of the extra weight by creating more power?
jerry S
New Member
65notch said:
a killer set for around a 1000 bucks? A new set of 185 AFRs are 1300 and even less used, prolly around your magic number of 1000. Nothing outflows them and that they are alum, they allow you to run a higher CR, which = more hp and a quicker ET.
brianj5600
Active Member
I have 185 AFRs and considered using body filler to fill in the AFR logo cnc'd into the front and then paint them. Not to try and clean up at the street races, just look original. In the end it seemed like too much work and I left them bare aluminum.
69Rcode_Mach1
Active Member
I was where you were, I wanted the stock look, I wanted to have a look similar to the Boss 302's all blue, with aluminum valve covers. I actually painted mine and mounted them, only to realize that even with self etching primer they do not hold the paint very well, it flaked and wore fast. So I stripped them back to bare and it really looks good.
Also anyone that is in the know will know that you are running aftermarket heads the machining is completely different, and there are freezeplugs in the head as well.
Also anyone that is in the know will know that you are running aftermarket heads the machining is completely different, and there are freezeplugs in the head as well.
Dark Knight
Founding Member
brianj5600 said:
so no one makes iron heads with the same port design as aluminum? how wrong you are. the only difference between the windsor jr/sr and the windsor jr/sr lite heads is the lite heads are aluminum.
the windsor jr heads have the same port volume and design as the edelbrock performer rpm heads. the afr 185 heads are also similar, as they have only 14cc more port volume.
most head manufacturers are casting aluminum heads because that is what the enthusiast wants, NOT because that is the best material to casr heads in.
jerry S
New Member
rbohm said:
not exactly an apples to apples comparison and not true. the Windsor jrs. have 180cc intake runners and 64cc exhaust runners. They flow 204 cfm intake and 135 cfm at .500.
http://www.worldcastings.com/tech/WindsorJrTech.pdf
The rpm performers like I have (60259) have 170 cc intake runners and 70 cc exhaust runners. They flow 251 cfm intake and 170 cfm exhaust at .500. The Windsors are very clearly not the same design as the edelbrocks.
http://www.edelbrock.com/automotive/head_flowdata.html#ford
The windsor jr. heads cost $500 each from summit. The AFR 185s are $1300 and flow 267 cfm intake and 185 cfm exhaust at .500.
the AFRs are clearly superior in terms of flow and will make not less than 50 hp more than the iron headed windsors. considering that you can run a higher CR with the AFR alum heads compared to the iron Windsors, then the AFRs could make as much as much as 75 hp or more than the windsors.
Now those iron heads can be CNC ported with a 5 angle port job but such a job is not less than $1000 and he would see only 30-50 cfm more intake over stock windsors at .500. That would give him heads costing $2000 that flow 254 cfm intake at .500 compared to the $1300 AFRs that flow 267 cfm at .500 out of the box.
blkfrd said:
using a hypereutectic alloy for heads would only net you a set of heads that are brittle, and will tend to crack. they will also be as hard to repair as iron heads, if they would be repairable at all.
jerry s, the windsor jr heads actually have 171cc intake runners, the windsor sr heads have 185 cc runners. i have a set of jr's.
jerry S
New Member
rbohm said:
According to this link from World's web site, the windsor jr's have 180 cc intake runners: http://www.worldcastings.com/tech/WindsorJrTech.pdf
and then this page from the catalog saying that the jrs. have 180cc intake runners.
http://www.worldcastings.com/docs/05_cat_pg24.pdf
Finally, this upload (also from World) also says 180.
Even if true that the intake runners are 185cc, then the intake flow at .500 is just terrible.
BlueMonster65
Founding Member
combustion chamber heat
i believe that the heat dissipation of aluminum vs. cast iron heads is being greatly exagerated in this discussion. the most important thing to consider is that heat is a byproduct of making power. once the combustion event takes place the heat that remains is doing nothing to help further the cause of making more power. and therefore if it is removed from the area so much the better. it is however important to control hot spots and cool spots around the cumbustion chamber which is more a function of the coolant path and engine design. this is where the iron heads which retain more heat will help maintain a more consistant temperature through out the engine. however this is negligible when compared with the performace advantages of aluminum heads.
to overcome any issues with electrolysis due to the different metals (iron block aluminum heads) being subjected to coolant. use the proper mix of coolant or distilled water. dont use tap water or water with a high mineral content as this will accerate the corroding process. and change it at recommended intervals.
modern manufacturing techniques and gasket technology have pretty much eliminated any issues with sealing and problems with warpage of Al heads.
painting the aluminum heads is good if you want them to look like an original set of heads. it won't affect heat retention and you don't want that anyway. if anything paining them black might radiate the heat even better, but only if you use a thin paint otherwise the paint thickness will negate any benefits.
i believe that the heat dissipation of aluminum vs. cast iron heads is being greatly exagerated in this discussion. the most important thing to consider is that heat is a byproduct of making power. once the combustion event takes place the heat that remains is doing nothing to help further the cause of making more power. and therefore if it is removed from the area so much the better. it is however important to control hot spots and cool spots around the cumbustion chamber which is more a function of the coolant path and engine design. this is where the iron heads which retain more heat will help maintain a more consistant temperature through out the engine. however this is negligible when compared with the performace advantages of aluminum heads.
to overcome any issues with electrolysis due to the different metals (iron block aluminum heads) being subjected to coolant. use the proper mix of coolant or distilled water. dont use tap water or water with a high mineral content as this will accerate the corroding process. and change it at recommended intervals.
modern manufacturing techniques and gasket technology have pretty much eliminated any issues with sealing and problems with warpage of Al heads.
painting the aluminum heads is good if you want them to look like an original set of heads. it won't affect heat retention and you don't want that anyway. if anything paining them black might radiate the heat even better, but only if you use a thin paint otherwise the paint thickness will negate any benefits.
In the May 2005 issue of Mustang and Fords there is an article about Power Heads in Fullerton, CA. (714-992-4909) www.powerheads.com
It states that they will cnc port iron heads with 1.94 intake and 1.60 exhaust stainless valves, chrome moly retainers, heavy-duty keepers and a .530 inch high performance spring package. Screw-in studs and pushrod guide-plate assemblies. Heads older than 1975 receive hardened exhaust valve seat inserts. That is you furnishing the heads. They state that at .500 valve lift, flow capacity on the intake to be 229 cfm. The exhaust side flowed 174.9 at .500 lift. If somebody wanted cast iron heads this might be worth looking into.
It states that they will cnc port iron heads with 1.94 intake and 1.60 exhaust stainless valves, chrome moly retainers, heavy-duty keepers and a .530 inch high performance spring package. Screw-in studs and pushrod guide-plate assemblies. Heads older than 1975 receive hardened exhaust valve seat inserts. That is you furnishing the heads. They state that at .500 valve lift, flow capacity on the intake to be 229 cfm. The exhaust side flowed 174.9 at .500 lift. If somebody wanted cast iron heads this might be worth looking into.
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