sschoeffler

iTrader: (24)

So I have an opportunity to pick up an LQ4 with 317 cheap ($450.00) and I dont know if its worth the extra weight to have the iron block or if I should just build up my LS1. The LQ4 is pulled from a stock truck, evidently a ring broke and needs a new piston ring but didn't scar anything up. My LS1 has the LS6 Intake Manifold and the 243 heads. The rest of the guts are all stock. So with a $2000 budget and possibly able to sell my old motor for about $1200 with stock intake and 853 heads. Is it worth the weight going iron? I "could" forsee a FI build going on but if that happened, it would be down the road a couple years. Anyhow, just basically wondering if its worth switching blocks. Either way, something is getting rebuilt soon.

sschoeffler

iTrader: (24)

Forgot to mention, I'm looking for about 650 RWHP on a daily driver

Crimsonnaire

iTrader: (1)

I would imagine there would be a significant amount of additional weight with the iron, plus you have the problem of rust over time. I don't understand why they don't imploy steel or some nickel alloy that is vastly superior to iron if you're gonna put up with that amount of weight.

I'm not sure what iron blocks have to offer that's better than the aluminum, but I've read that the LSX iron motor is supposed to have a threshold of 2500 BHP.

sroach20

iTrader: (31)

lq4 would be a good foundation for future big cubes, like a 408. you only pick up 70lbs of weight. ive got the lq4 in mine and im about to stick the l92 heads on it. later on i will do the 408 and it will go great with the l92 heads. rust? i dont know what the hell the other guy is talking about. these engines dont rust unless you pull it apart and leave it sitting in the yard.

89IROC

iTrader: (2)

+1 on that never can go wrong with larger displacement, plus like mentioned the 6.0 allows for the use of L92 heads where as the smaller ls1 bore wont allow it....No rust issues..... there are plenty of 60s and 70s era cast iron 350s running around no problem....rust is no real issue, clean the block up and paint it.......70lbs isnt a big weight issue either...

SOMbitch

iTrader: (8)

you must be like me and want it to turn an a dime and be very precise, I am going 383 when the time comes becauce i love my handling charactertstics and plan o making it even better It can be done quite easily and for the most part cheaply. Just gonna stroke my LS1 or go 402 funds permitting when it's time.

zachness

70 pounds over the nose is more wieght for the rear tires to fight to get the car moving; so less traction from a dig. This is the only difference in performance if you just want to drag with that much power. I say keep the aluminum block and forge what you can.

wht01ws6ta

iTrader: (45)

Alluminum, is that one of those new high performance metals?

I would go with the iron 6.0 block. You can do a lot more with that wider bore. After hearing about oiling problems common to the 383s I am not sure I would want to go that route. What heads do you plan on running on it? 243 will make your compression high, the 317 are good for boost. And you can always run L92 heads...

Soul TKR

iTrader: (4)

I went LQ4 and didn't notice any difference at all in the way the car handles... the bigger cubes also allows for a steady TQ curve across the WHOLE rpm range as well... doesn't drop like smaller engines would...

wht01ws6ta

iTrader: (45)

I bet your LQ4 does have a very steady torque curve with the bigger cubes and the smaller 224 cam in there. That's got to be a very streetable choice that will still put out some nice power everywhere in the RPM range.

wht01ws6ta

iTrader: (45)

So, what did you get?

siffert

iTrader: (1)

I agree.

dogger

iTrader: (1)

actually lighter isn't always better when it comes to handling. in 04 they tested a bullit a mach one and cobra mustangs. the best handleing was the bullit with a iron block and heads followed by the mach one with a iron block and al heads then the cobra with al block and heads. the 600foot slalom speeds were almost 2mph different between the three car's.

sschoeffler

iTrader: (24)

I bought an LQ4, L92 heads, L76 intake, 4" forged eagle stroker crank, 6.125 forged eagle rods, 4.030 JE pistons.

Now I'm debating boost or nitrous. tough freaking decision. I've got pistons set up for boost but I dont know if I wanna go that route as this is getting very expensive, very fast. Already got over 3k invested and havnt had any machine work done.

Eagle Performance

So the iron block is capable of a bigger bore? 70 lbs, I thought it would be more. I've been trying to find out the difference between the two blocks, the LS2 is 6.0, are these sleeved or are they coated walls? Is the truck block the same bore, still trying to figure out why/what the difference is between the 402 & 408.

sschoeffler

iTrader: (24)

Well, The LS2 is a sleeved aluminum block, the LQ4 is an Iron Block. The Iron block is a tad bit bigger. Iron block will inherently hold more boost/nitrous because of its composition. The LQ4 is 364 cubic inches, and not sure of the LS2 but I know its a little less.

rookie89

iTrader: (1)

Were they all stock 04 cars? I only ask because lighter is pretty much always better unless theres a rediculous difference in weight distribution (some of which can be accounted for in the suspension setup). Plus the cobra would have had an iron block with a big metal blower on top, a heavier tranny, heavier interior, and heavier rear suspension.

SICKSS/Z28

there is about a 90lbs difference

1slowfbody

it's actually closer to 110lbs

yonerhottlt1

iTrader: (21)

I could have sworn LS2's were 364 cubic inches too. IIRC theyre the same size. And I thought iron blocks were more closer to 100 lbs. heavier as well.