ZMONSTER!

iTrader: (9)

Thinking about options for a new motor if and when my motor goes. Only thing I dont know is which is a better material for a motor that will be 90% dd 10% track car.

NemeSS

iTrader: (127)

i have ran 6.0 based motors for 1,000s of miles, no problems
aluminum blocks cost more.
4.030 6.0= 370ci LSx

99blancoSS

iTrader: (115)

Iron is more durable/stronger than aluminum thats just a fact. But thats not to say an aluminum block wont last either.

Best bang for the buck is an LQ9 408, the block is $300 less than an aluminum ls2 plus you need a conversion kit for the ls2 if you have an ls1. The ls2 403 is 4.005 bore x 4.0 stroke while the lq9 408 is 4.030 x 4" stroke or if your not going to use a power we add we do a 418 with the LQ9 for an even better CID/$.

Soul TKR

iTrader: (4)

just from my experience, my iron block performs very well and I didn't notice a weight difference at all as far as the handling and power the car makes...

Engine_HP

iTrader: (1)

IMO aluminum is always better iron. u need lighter weight to performe better.

ndfrsd6

iTrader: (5)

i have an aluminum 402 setup ,unless your going to spray or FI it why have the extra weight

SOMbitch

iTrader: (8)

That is why I will either just stroke my current block to 383 or go 402 But I know a couple guys spraying a 150 shot no probs on LS1/6 blocks. As Blanco says if you want more cubes than 402/3 you will have to go iron (or LS3/ LS7).

99blancoSS

iTrader: (115)

I would love to know how your going to make more power with an aluminum block over an iron block?

Its 75 weight difference which can be offset in other area's.

ZMONSTER!

iTrader: (9)

Ive always been told aluminum blocks were better because in the event of a damaged block they can be repaired, where Iorn blocks cannot.

99blancoSS

iTrader: (115)

Actually its the oppposite. Unless your overboring the iron block to much in the first place it leaves room for repair.

Soul TKR

iTrader: (4)

dunno if that's true... but iron blocks are less suseptable to being damaged in the first place...

davered00ss

iTrader: (4)

Iron is stronger, but I prefer the aluminum block for weight reasons. 75#'s is a lot to make up in other area's.

99blancoSS

iTrader: (115)

battery and k-member = how much?

Most guys making serious FI power dont mind the added insurance weight but we do see a lot of Vettes stay with aluminum for weght reasons. Just 75'lbs can be huge to one person but not much to another.

Jpr5690

iTrader: (13)

i think it ultimately depends on appliocation and power goals

id say n\a and under 700 hp can go with alumn
but
power adders and high hp should go with iron

75lbs only takes max 10-15 hp to compensate for so solong as were talking drag car id go iron

also keep in mind iron blocks usually need bigger radiators so i really dont buy the cost difference argument....

either way youll be happy just think of your long term goals before decideing

SOMbitch

iTrader: (8)

For me it is not the extra weight it is where the weight is. I like the twistys and don't want any more weight over the nose. One reason our engines are set so far back under the cowl was to improve the front to back weight ratio to make the car handle better. If I wanted an all out drag car HELL YEAH I would go iron!!!!

99blancoSS

iTrader: (115)

All good points. I went with a sleeved LS2 but I have 5 iron blocks in the works right now for customers all running street cars.

You don't need a radiator swap so lets squash that right now. There is about a $600 cost difference between the two when all is said and done. Some prefer to save that $600 and put it into a new rear. You can also get more power from the bigger cubic inches.
If money wasnt that big of an issue our LS3 416 is a great way to go!

davered00ss

iTrader: (4)

K-member and A-arms does not add up to 50lbs savings. Battery is nowhere nera 25 lbs savings either, so the 75 lbs is a lot. Pluss $1K for K-member & A-arms beats out the $600 for the cost difference in the aluminum block.

It's an opinion, and either way you decide to go is up to you. If I were looking for 1000rwhp turbo, I would go iron, N/A or some FI Aluminum.

davered00ss

iTrader: (4)

If you have the $, LS7.

Black01M6SS

iTrader: (3)

Show me some pic's of engine's that failed because of the aluminum block. Everyone always argues that iron is better because it is stronger. No doubt iron is stronger but I've never seen anyone say "yeah I hit xxxx rwhp and the block split apart". The point is the block doesn't need to be made out of iron when aluminum holds up just fine.

Show me a cheaper way to save 75#'s on the front end. As Dave said a K-member and A-arms cost more for less weight savings. Not only that but if you are going all out with weight reduction you will have the K-member and A-arms anyway so you are still 75 pounds heavier with an iron block.

I just haven't heard of enough people having block failures to argue that you need the extra strength of iron. I look at it as 75 pounds saved for 600$. Saying you went with iron because it wasn't worth the extra cost to save the weight makes since but saying you went with iron because it is stronger doesn't really make since when aluminum is strong enough.

2000Hawk

iTrader: (5)

What kind of performance mods do you see in the long run for this engine. Aluminum is just as good as the iron, don't let people tell you otherwise. Obviously the iron is a stronger block than the aluminum, but if your not going to be in the 7-8-900hp+ range, then the aluminum is just as good. Drawback of the iron has been stated which is the added weight, and the pro has been stated which is the cheaper price to that of the aluminum block. If the added weight bothers you then you can pay the extra money for aluminum. You said its going to be 10% track, so your not going to beat on it that much im guessing. Except for the occasional WOT blast on the street either block will suit your needs. Again im saying all this not sure what plans you have for this motor.
-Joel