1996LT1NY

just a guess.. but I don't think Dwaynes issue is to say iron is the way to go for a performance head. I think it's more that so many people dismiss them as total junk and they are not. At least I think that is his main point. If youre building a motor with stock unported heads whichever way you go is not going to make too much of a difference.

Some of this comes from the fact that years ago, some people in the Impala SS community were buying aluminum LT1 heads & putting them on their b-bodies stock unported & expecting some sort of gain in performance. That situation hasn't been seen here too much since F-bodies didnt come with iron heads It actually happened quite a few times & the fact is that swapping stock irons for stock al heads isn't really going to do anything & vice versa.

I think the whole debate doesnt really have too much of a point since most "LT1 people" who are serious about making HP are going to go for ported al heads anyway except for those few that want to prove something with stock heads.

96capricemgr

As for my typing I type with about 4 fingers and my brain works faster than they do , and I know that even beyond that my spelling can suck, in school I was far more interested in science than english.

Yes, you are getting my point, as far as using iron in a performance application yes it still has a place it just will not be in every car. As far as race cars who cares I thought were were here for performance street cars we occassionally race for a bit more fun on the weekend. Yes people spend a lot of money to reduce weight but that does not mean it is the most cost effective way to go faster it is just one of the ways. There are a few LS1 cars that have seen my tailights past the 1/8th mile at the strip, they have more power than I and a lighter car BUT even on street tires my porky car just plain hooks, doesn't matter how much power you have or how light the car if it is just smoking tires rather than accelerating the car.

That spare head is in the back of my car it has valves and springs.

Buttercup

Well, to make this REAL easy let me ask you. If your b-body came with aluminum heads, would you have swapped them for iron?

Didn't think so

If this person had an Impy or something there might be a question but with an f-body or 'Vette I just don't see the point.

On the subject of weight, it doesn't have to be a race car. My attitude has always and will always be to get rid of unneeded mass. It helps with handling, braking, acceleration, fuel mileage, etc. I'm not about to spend big bucks on it but I sure as hell would never add weight if it didn't serve a purpose and will always try to lose weight if I can cheaply and easily do so.

Stock LS1's don't give me any trouble either. I can whoop them with the AC on and the stereo thumping I managed 30 mpg on the highway this weekend.

birdofire

Another popular misconception about going fast: because I have weight, I hook and therefore I must be faster.

Right, to an extent. On a stock suspension car, its where this weight is that allows the car to hook. However, once you hook the pavement, the weight is the detriment (except wind resistance) in making the car get down the track fast enough to beat the other car, which is the majority of the run.

The solution: get the suspension to work with your car. I will not get into suspension as there is plenty of information out there on how to properly set up any car, but there is a reason why plenty of 2000 lb. race cars routinely pull 1.2 sec. 60 ft. times, which couldn't be done in a stock Impala if the power WAS available to do so.

F-bodies are set up for multi-purpose sporting events, including autocross. This compromises their ability to hook at a dragstrip because they don't transfer weight as effectively to the rear wheels as a drag only suspension would. I guarantee you that if you run an LS1 F-body utilizing a drag suspension to launch, it will leave an Impala hard (stock for stock). Case in point: first LS1 F-body in the 7's. Think his 60' is slower than a 4000 lb. tank?

You are 100% correct. It doesn't matter if you have all the power in the world, if you fry the hides, you lose. Just don't use weight as an answer to make your car launch.

breakmyfootoff

I did. To me, the better head gasket retention of the irons was worth the extra 40 lbs. I had some ported aluminum castings but I know too many people that started lifting the heads and blowing head gaskets with large doses of nitrous or lots of boost. To me, the best heads for boost or nitrous are thick deck AFR heads or irons, and I'm not about to dump 3000.00 dollars on the AFR's. I did lots of research before I decided to go with irons and the only area that aluminums really had an adavntage in was wieght. They were not the cheapest route to go either, with all the machine work included and porting, and purchasing the cores I have about 1000.00 into them. The really fast guys run aluminum, but durability is not one of their primary concerns. Every ounce matters to those guys, are you willing to ditch your AC to save 40 lbs, maybe you are, I'm not.

Buttercup

Nope, won't ditch my AC because I use it. I've got a big subwoofer and amps in the back too because I listen to the stereo as much as I listen to the engine. In fact it drove some guys crazy that I didn't remove all this crap when I went to the strip

The iron heads are simply needless weight so I wouldn't run them. In your case you do have a reason. When I finally go with boost I'll have enough money in the car that the extra investment in good aluminum heads isn't of much concern

breakmyfootoff

All that being said, you are right. I wouldn't have switched to them if I was still runnning naturally aspirated, but in my case the AFRs would flow somewhere around 40 cfm more and wieghed 40 lbs less. If I was looking to be top dog I would have tried to get AFR heads but for something I just want to have fun with I couldn't justify 2000.00 more for just 40 lbs and 40 cfm. I guess it just depends on your goals for the car.

96capricemgr

I am not trying to get anyone to swap to iron, just trying to dispell the iron=bad misconception. Listen to the ignorant here and you would believe a swap to aluminums would gain me a whole second or something, when as 1996LT1NY stated stock for stock it would simply be a waste of effort and I actually know someone who did this before we met and he was disapointed, he had ASSumed that those 96 Vette heads would be some wonderful upgrade for his 96 Caprice.

On the weight thing I weighted a stock 96 iron head with springs valves the whols shot right down to a good layer of grime and it would appear that the 50# number is pretty damn close so I was wrong and will be contacting my source . The head I weighed was 44pounds 12ounces, the springs 1996LT1NY's heads were missing would probably bring the differnce into the 23.X pounds apiece range for a total somewhere around 47lbs.

As far as weight and traction I didn't mean that the weight was the reason for my traction, just that with this car and it's ability to hook I can still be faster than lighter more powerful cars despite my extra weight. I really think a lot of it is the chassis, it just works well. My only traction mod at this point is Airlifts with offset pressures to keep her level on launch I do have aftermarket lower arms but those did more for handling, once I get my instant centers welded in though I see 1.8s on street tires as a certainty.
To me I want to drive a car, most of the time at the dragstrip I leave the spare tirea and all in the trunk and will not do drag shocks or the like that would compromise everyday use. I know I could be faster if I yank the swaybars and passenger seat and all that but I go to the track to have fun and don't want to spend the next day putting my car back together.

Wonder if this thread will hurt AFR head sales I mean damn adding weight, surely they couldn't be worth it

hvyss

I have used both. Ported iron and ported AFR 190cc heads. I started with pocket ported iron with stock valves and a zz3 cam(which if I am not mistaken Dwayne is using now), 1.6/1.5 rocker mix and a SLP 2400 stall and stock shortblock. Coupled with 3:73 gears the Impy ran a best of 13.6 @99. I installed a Yank 3500 and dropped to 13.2@101. So I thought WOW with a set of AFR aluminum heads ported and polished and a bigger cam (lt4 Hotcam) and 1.6 rockers this car will easily hit 12's. NOT! The best was 13.19 @102 with ED Wright tuning and 4.10 gears N/A .

Well the stock shortblock took a dump. Dropped a valve and put a large hole in #7 piston. Did some damage to the combustion chamber also on the head. So I decided to build a forged 355. 2 bolt main with 4340 GM crank, Eagle I beam rods and SRP pistons and ARP everything. An Impy buddy had a set of Agistino (I know a dirty word on this forum) ported Iron heads done back in 99. On his 383 the car went 12.2's in an Impy. So they went on my car after having them redone. They have 2.05/1.60 valves and only flow 267cfms intake and 206 exhaust @ .550 lift. With a comp cams 503(224/230 vs 218/228 on the Hotcam), 30lb SVO's and 1.6 rockers (.536/.544 lift vs .525/.525 on the Hotcam) the car has gained over 3 tenths of a second and 6 mph from the AFR's and Hotcam using Bryan Herter tuning and the help of Tunercat. This was on a day with a temp of 85 degrees, 94% humidity and a corrected altitude density of 3700 ft.

In my case the iron has done better for me than the aluminum. The cam I run now is marginally bigger that the Hotcam. So in my case the lighter aluminum heads did nothing for me. At 4400 lbs 40-50 pounds doesn't mean s^%$! And 5 Cubic inches also doesn't mean much either. Will I try aluminum again ? Probably. I am working with AI on a set of LT1 casting aluminum heads CNC ported and a solid roller cam. We will see
HVY SS