headed-ws6

iTrader: (34)

I agree with predator on this. An ls1 block will hold power just fine for 90% of builds out there given the tune is good. I myself went with a iron block 347 because i could get it for 75 bucks rather then 300+ for an ls1. if you looking for an affordable block to get you where you want the iron will do great and hold up well.

revtech101

You will crush/spin your rod bearings with knock. Then the block will crack after your rods go right through it.

Knock will kill any motor period. I'm not even sure what you are implying here.... That the iron block will take more knock before it blows? Your motor is NOT suppose to knock in the first place.

You are going about this the wrong way.

KCS

iTrader: (20)

I'm saying the iron block will survive a bad tune better than an aluminum block will. You can crack a LS1 sleeve from detonation before breaking a piston.

Am I the only one that read that the OP is worried more about reliability than weight?

aAZz

Any pics? Dyno numbers? How do u like it compared 2 a true ls1?

revtech101

There is no such thing as reliability with a bad tune. If you are breaking your block, you have other issues to deal with. A good tuner is more important then choosing between an iron or aluminum block.

aAZz

I have a good tuner down here in phx that knows his lsx motors so I'm good there guys. Lookin for performance but most importantly reliabilty plannin on a big cam and 100 shot of nitrous

King Nothing

iTrader: (9)

I was wonderig the same thing, in fact I was the first person to chime in lol I'd love to go iron 347 but I don't want a stroked engine so I might have to go with a aluminum block for a 347

KCS

iTrader: (20)

Sure there is. Poor tuning doesn't always destroy an engine, its the REALLY poor tuning that does. Like I said earlier, I have personally seen an engine with detonation issues that cracked the sleeve of the block before the piston gave up. I would consider a block that doesn't break before the OEM piston does to be more reliable than one that does, wouldn't you?

You don't have to stroke an iron block to make it a 347. You just bore the cylinder out to 3.9xx" and use a stock 3.622" crank. That what I'm doing.

King Nothing

iTrader: (9)

Sweet thank you!!!!

revtech101

Technically speaking, its not the really poor tuning that kills a block, its the over aggressive tune that does. I understand you saw what you saw but there is no reason to rule out the possibility of other variables that could have caused such a catastrophe. I once saw a dog walk on 2 legs on its own. Not for a second did I assume all dogs can pull this off.

KCS

iTrader: (20)

Go ahead and explain how a tune that blows up the engine isn't a poor tune.

Well if the piston in the adjacent cylinder came apart, and the piston in the cylinder that cracked showed damage from detonation, there is no reason to believe aliens did it. That cylinder had detonation issues, no doubt about that, and as destructive as detonation is, there really is no reason to suspect anything else.

headed-ws6

iTrader: (34)

before i went boost the motor had a 02+ zo6 cam and stock 243's and full bolt ons and would hang with cammed ls1's. power is the same as a ls1 you just have an iron block instead of a aluminum block.

brianw401

iTrader: (4)

I feel that it depends on the tune. I know a couple of dudes that are making over 1,000whp. with aluminum blocks (however, they are not LS1). It couldn't hurt to go iron if you are shooting for huge power numbers. Iron won't flex as much under extreme heat & pressure like aluminum will.

aAZz

No power wit this block is a little over 450rwhp that id like 2 get. I'm goin 2 build a lq9 as well. Once that's done I'm putting this in my fox and lq9 on my nova

revtech101

The clue to the destroyed block was detonation and yet you blame the aluminum block? Why? How did you reach that conclusion? The suspect was the tune as YOU clearly mentioned yourself.

I won't bother explaining a poor tune vs. an aggressive tune. Its just plain silly for me to try and explain that especially if you do not tune your own cars.

KCS

iTrader: (20)

The block cracked before the OEM piston, therefore, the block was the weaker link here. There's no doubt that detonation was the cause of all that damage, but it wasn't even that bad, and it should have been a case where all we had to replace were the pistons. Unfortunately, the block failed as well. The problem probably was the tune, but that's not really even relevant. My point this whole time is that an iron block will typically withstand more abuse than an aluminum LS1 block, so even if you get a bad tune or a bad tank of gas, at least you won't be having to replace the block.

Don't try to insult my intelligence to cop out of having to back up your BS. I'm not a tuner, but I've had enough experience in a dyno cell with the likes of Don Bailey and DaVnci to keep up with anything you have to say. So again, go ahead and explain.