cast iron vs aluminum

[srtthis]

what are the pro's and cons of each?

cast iron
pro's
cost
Con's
weight

Aluminum
Pro's
weight
con's
cost

im trying to make up my mind if aluminum is really worth the extra cost on a street car. i know down the road when i build a bigger motor ill get aluminum heads to cut weght on the car but is it really worth it for a stock bottom ended 302?

 

[UPRMike]

You've summed up the age old debate perfectly with one missing part: performance and flow. Stock E7TE heads are great for pickup trucks and Crown Victorias. Assuming your stock bottom end is in good shape with a decent ring seal and maintaining proper oil pressure, the answer to your last question is definitely.

Just for example, the Edelbrock E-Streets for SBF (5025 and 5023) are selling for less than $1000, ready to bolt on, from the big warehouses. By the time you properly rebuild a set of stockers, you're halfway to buying a brand new set of aluminums.

If you put any real money into stock heads for good valves and porting you've now spent almost as much as a set of aluminums and have a set of maxed out heads that are as good as they can possibly be. Aluminums will start you off at that point (or better) as they are, and allow you room to grow later.

 

[347HO]

If you're not "class" racing, a good set of aluminum cylinder heads is the way to go... hands down.

Aluminum will allow you 1pt up in compression for its ability to shed heat.

Inline and < 15* valve angle such as World Products Man O' War 10* heads promote very good performance.

Twisted Wedge and Canted valve (TFS and C302b) in aluminum promote even better performance.

As stated previously... you can put money in iron heads but for every dollar invested, you can make the aluminum style perform greater.

TFS Street Heats in iron are very good.
RHS215 in iron are pretty good too.

 

[srtthis]

i was looking at the world product windsor sr's vs a set of afr 205's/ trick flows.
almost double the cost for the afrs over the Sr's

for the money id could almost buy a 347 stroker kit.

 

[srtthis]

wow just looked into the E streets thats a pretty good deal for some aluminum heads

 

[phutch11]

205's on a 302 isn't what most would call a "street" combo.

If you aren't running big cubes or a huge non-streetable cam; you may want to consider much smaller heads - I.e. AFR 165s or the E streets.

Good luck...

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[srtthis]

i had planned to do something a little bigger in the bottom end like a 347 or so. if i can save money hear and there on this build i can get to the BIG motor faster

 

[Brando5641]

all 205's are going to do to shave time off the clock is make your wallet weigh less.....

 

[-Nick-]

You've summed up the age old debate perfectly with one missing part: performance and flow.

flow numbers mean next to nothing.....

 

[90mustangGT]

All about cost. Is the extra money worth it? Well you are talking about a stock bottom end, and one day to make a larger engine. Well getting heads that would feed a larger engine will not be ideal at all for the current bottom end. Aluminum's weigh about 60% of what the iron heads weigh. Yes it's a weight savings but not worth the cost there, might save 20-25lbs. Stock compression isn't enough that this is an issue to make aluminum worth it. Save some money on the heads and put it towards the larger motor.

I did the infamous Thumper E7's on my car when it ran. I'll be honest with you, I was quite impressed. 1/8th mile I ran 8.4's at 85mph on 17" wheels on a track where everyone ran at least .2 faster other tracks. I had to launch from just a fast idle (1500) and had to feather it quite a bit. All NA, Edelbrock intake, longtube exaust, a few weight reductions, but nothing major.

Next time? Hmmmm.... this all depends. I'll put it this way, I'd save the money and put it towards a better bottom end worthy of expensive aluminum heads or a turbo/supercharger.

You can make more power than the block can handle with stock heads quite easily.

There is also the GT40 Route.

 

[srtthis]

heres the plan guys...

im gunna get a set of e streets i believe HOPEFULLY these will be able to flow enough to feed the hi compression (12:1 or higher) 347 i have planned for this while its a street car. the plan after that is to build a higher compression 410 with all the goodies and a c4. but thats once i feel like taking it off the street so i got some time. i just want a solid high 9 second street car till i pull it off the road.

 

[phutch11]

You need to be careful with your cam selection if you go with the E-streets. They have springs that won't handle much lift - something like .480; but check with Edelbrock.

Good luck...

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[srtthis]

id be pulling the springs anyway... i think it was something like .500 lift. and i already have an E cam which is .498 so to be on the safe side id like springs that can handle around .550 or so with this cam. i need to talk with don burton about some nitrous cam specs to see how big i need to go on the springs

looks like the springs are good for .550 already
http://www.edelbrock.com/automotive_new/misc/spotlight/e-street.shtml

 

[90lxcoupe]

why not just pick up a set of used AFR's or twisted wedge heads for cheap, throw a shot on it, skip the 347 and start building that 410

 

[srtthis]

why not just pick up a set of used AFR's or twisted wedge heads for cheap, throw a shot on it, skip the 347 and start building that 410

few reasons...

the 410 would be a completely over the top motor so the cost if going to be crazy... this point in my life i just dont have that kind of money laying around. so a 347 is a happy medium for me. the 302 in the car now i really dont know alot about since it was like this when i got the car. i want it down this winter anyway and go over everything to make sure its ok to handle what i want to throw at it till i can do the stroker.

plus a carbed 410 with a c4 on 2 stages should go 8.50's so i need something in the middle between what im use to and that

 

[Mustang78]

351w? seems like a cheaper, stronger alternative that you can build up later.. and +1 for used aluminum heads i've seen a few nice barely used pairs go for 1,000

 

[mob]

Sometiems a set of used aluminum heads can end up costing you more than a new set. Be careful. If you go with irons you will be holding yourself back no question about it, if you just cannot afford aluminum then you gotta do what you gotta do and stick with the irons. But there is no comparison. I myself have been itching to try a set of the old style iron trickflow heads, I see them going on corral for around 500-600 bucks.

 

[90mustangGT]

Sometiems a set of used aluminum heads can end up costing you more than a new set. Be careful.

Good point, so be carefull what you pay and what you get. If I bought used heads, new/upgraded valve springs would be a must. A bad valvespring can cause hell. They are too critical and too cheap to skimp on.

 

[old_blue]

I was dead set on thumpers for a long time. $6-700 and you get a great bang for the buck performance. but now edelbrock ups the ante a little with the $949 e streets........ next tax return I will be going with these now. from my research here is what I found.

thumper heads-
@.500 lift you'd get 218.9 intake and 154 exhaust on thumpers

e streets-
@.500 lift intake 248 and exhaust 163- fantastic for out of the box under $1000..... just me though

.500 lift is plenty for what I am looking for. good luck with your build.

 

[Foxfan88]

i ran a set of thumpers for a while on my car. they are great heads and are a definate upgrade over stock.. but the aftermarket aluminum heads take the cake.

A set of AFRs or TW heads out of the box will flow more that pretty much any ported stock castings. I imagine if you had the cash and was willing, you could make a set of stock heads flow better than the aftermarket, but you'd have more money in them when you could have got a set of aluminum heads.

Plus the weight savins are a pretty big difference. I weighed my full assemble stock castings and they were around 48-50 lbs eash, while a fully assembled TW head was around 26lbs.... your saving around 50lbs off the front of the car.

IMO spend the 1000-1500 for a nice new set of aftermarket heads and be done with it. I got my TWs and never regretted it...wish i would have done it the first time, they make good power out of box and they have even more potential when ported out some.