projectcam

iTrader: (12)

I just got off the phone with a reputable machine shop here in Phoenix Arizona to get a 5.3 block bored to ls1 specs. I currently have a turbo car with a GTM-78 and a virginia speed built 347 making good power and have not had any problems with the block or head gaskets to date. I explained to him that I want to switch my setup and go to an iron block and o-ring to step up the power more and have it be somewhat reliable. He told me that the he has seen Iron blocks fail and split the main webbing on the block at less than 1400 flywheel hp. I have been messing with these motors for a very long time but I can't compare what I have seen to someone that runs a machine shop. I would like to see if anyone out there using any of the iron blocks listed (5.3, 6.0) Have ever had one fail at that power level?

hellbents10

iTrader: (10)

I have never seen it myself but then again I have never seen a 1400hp engine based of a 5.3l.

With the 5.3l casting and the 6l casting being so similar, save for the bore size I can not see it happening either???

9sectruck

iTrader: (9)

I have personally never seen that kinda hp out of a iron block but heres the 4.8 link that made 1204 on a stock block
http://www.norotors.com/index.php?PH...0643#msg110643

projectcam

iTrader: (12)

I know at least 5 people that have made 1k rwhp with the lq9/lq4 block. I bought a 5.3 block and planned on boring it to 3.900 with a set of All pros on top of it with a pro mod 88. The hp level should be up there if it stays together but I am starting to second guess if I should save for an aftermarket block. I didnt think it was neccesary.. Just looking to see what other engine builders have actually seen come into there shops. I want to know if anyone has actually seen one fail like I was told. I have heard and seen aluminum blocks lose there shape and even break before but never an iron block. I know andreas from Swedan made a shitload of power with a lq9 block and his fire rings.

projectcam

iTrader: (12)

http://www.theturboforums.com/smf/th...5hga8i4purue27

hellbents10

iTrader: (10)

Well there you go, I couldn't imagine the block being an issue with proper prep.

projectcam

iTrader: (12)

So there you have it then. I guess no one has ever seen a block fail sure to its design. Guessing the machine shop was blowing smoke.

got-a-ls1

iTrader: (12)

maybe you misunderstood him and he has seen the old 5.0 blocks splitting at 400 flywheel horsepower... lol. never heard of a ls or iron block splitting??

projectcam

iTrader: (12)

When he said splitting I told him I wasn't talking about a ford motor lol. He most definitley knew I meant LsX based.

slow67

iTrader: (2)

One guy with a Nova and a 91mm went mid 8's for a couple of years before splitting a 5.3L bored to LS1 specs.

He's on the bullet and the turbo forums.

Fbodyjunkie06

iTrader: (10)

I was just about to say the same thing.

Ultimate 346 is his name IIRC.

I'd leave it at 5.3 specs and put a girdle on it, and if your car already doesn't have a midplate that will also help with stressing the block from twisting as will the girdle.

I don't see a 327 vs. 346 spooling a pro mod 88 any quicker, matter of fact if the right cam and timing table/fueling table is being utilized then they should spool identically.

HexenLord

He didn't split the block. A piston skirt fell off of one of his pistons making a mess of the cylinder wall. The block itself never failed. He switched to a 6.0 only because the block couldn't be over-bored enough to fix the cylinder damage.

a4ls2goat

what machine shop was this?

gjohnsonws6

iTrader: (12)

^^ what he said ^^