Jim85IROC

iTrader: (6)

I realize that this thread is redundant, but between the lack of a search and the million-reply stickies, finding the specific info has been very difficult, so I'm hoping for help here.

After I sell my Corvette, I'm planning to do a motor/trans/rear upgrade to my IROC. This thread is mainly about the motor. I want to establish a solid game plan before I sell my Corvette so that I'll know exactly what my budget is and exactly what parts to start buying. So, in order to establish this game plan, I need to explore possibilities which includes a parts list and estimated cost for said parts list.

My goal is basically to go as fast as possible with my budget, and while maintaining daily driver manners and reliability, even though this car won't be a DD. I expect my budget to be around $10k, which realistically leaves me about $5k after I buy the T56 and 9" rear.

So here's what I see for options:

1. Get a complete motor:
1A. high mile LQ4/LQ9 & a rebuild + heads, cam, intake.

1B. low mile LQ9 + heads, cam, intake.

This gets me most of what I need right away, but then I wind up with a bunch of junk I don't need that has minimal resale value. In both of those cases, I'll need f-body accessories and an f-body oil pan. What else?

2. Build bits and pieces
2A. Get a bare block and build a nice stroker as the budget permits prior to selling the corvette.

2B. Scrounge around for a good shortblock to build upon.

In both of these cases I wind up with exactly what I want and I don't spend money on a bunch of crap that I'm not going to use, but I also run the risk of burying myself in the budget because of the need for a million small parts (sensors, harness, ECM, ? ? ? ?).

Some generic questions:
1. Is a heads/cam/intake LQ4 or LQ9 going to make at or near 500hp with strong torque? Can a stock short block handle that power reliably?
2. In all scenarios above, I've been looking at the L92 heads, along with the L76 intake. Are there more affordable ways to get the kind of power I want? I don't mind used parts, but it seems that by the time I have somebody go through a set of used heads, I'll be in for more $$$ than buying new L92s. Likewise, a Fast intake alone is twice the cost of the complete L76 intake/runners/tb.

Sorry for all the noob-ish questions, but these are a lot of questions that I haven't been able to answer myself by reading the forum. A lot of it involves getting opinions & ideas from others who have gone down similar paths to find out what is going to be my best approach. This will basically be a 1-shot deal for me to do. I've spent virtually no money on the IROC in years because life keeps getting in the way, and having bought a house a year ago, getting married next month and no doubt having kids in the near future, the reality is that it's very unlikely that I'll be able to spend any real money on the car except for the $10k-ish that I expect from selling the Corvette, so I really need to try and squeeze as much of it in at once as I can... at least the big stuff. A couple hundred here or there to finish it up isn't a problem, but there's no way I'll be able to drop $2500 on a trans or rear end down the road.

All opinions are appreciated.

Jim85IROC

iTrader: (6)

BTT. Just hoping for some opinions from guys who have built up some 6 liter motors.

ghettocruiser

iTrader: (17)

I know you asked for advice from guys that built 6.0Ls...but I just thought Ide throw some other ideas at ya. You are essentially going to have about 5k to spend on just the motor correct? Sounds about accurate after a 9" and T56...depending on what those consist of.

5k gives you a couple options. If you are dead set on a 6.0L, you can surely get a stock motor, build it some, change the intake, and have a pretty stout set up. Also...Ive seen guys get bare blocks from some of the site sponsers such as 408s or 427s and building them for close to 5k. You might be better off going with a custom block and just building what you want. As for accessories...sometimes the best route for that is to try to find a package deal. Like find a blown motor, or find someone that replaced all the accesories to go into a hot rod or something. Piece those together can get pricey sometimes after you get all the parts and brackets and odds and ends.

Just a thought... Might want to give a couple of the site sponsers a call and talk about options, combos, and prices.

Do you want to go iron block? Or would you stay alum. if you could? Planning on boosting it or pushing a big shot through it...or staying NA?

J.

Jim85IROC

iTrader: (6)

I think aluminum would be neat, but would probably hurt the budget. It seems like my money can go farther with iron, plus it gives me the option to do an overbore down the road if necessary.

As much as I'd love to supercharge or turbocharge, that would be way out of the budget, and isn't something that would be likely in the future either, so I'd say no. However, I do think I'd like to add a 150 shot down the road, so if I can afford to, I'd like the motor to be strong enough to handle that.

Maybe I should give SDPC a call and see what kind of money I'd be into if I planned a 6.0 stroker with the L92 heads and L76 intake/tb/injector combo. I have a feeling that by the time I buy a motor and rebuild it, I could have just gotten an SDPC short block for around the same coin. SDPC short block + l92 heads + l76 stuff + cam + accessories + oil pan + harness + ecm = way more than 5k

On the other hand, I could spend a bit more on a lower mile LQ9 with the intent of just bolting the heads/cam/intake on to the stock shortblock. Would the stock shortblock survive at that power level? What about with an additional 150 shot?

Spike-Z

iTrader: (2)

A good friend of mine has a '99 T/A. Stock 5.7 shortblock, ran 11.2x 2 years in a row w/ 150 shot. Now that was aluminum, cast iron would probably do better. Of course his valvetrain is upgraded tho.

merriman44

iTrader: (4)

brand new 6.0 ls2 block is only a grand. thats just a few hundred more than the iron block. And that shaves off around 80 lbs. That'll help the front/back weight ratio. I don't know but I'm going aluminum for many reasons but this is definitely part of my reasoning. Also, aluminum blocks take 150 shots just fine. Its usually something else stupid that goes wrong like a piston explodes or a rod goes or etc... Just my novice .02

merriman44

iTrader: (4)

Also you can get a brand new set of ls6 heads from Patriot performance for less than 500 and that way have a bit better compression. Thats all good in my book

ryanvv355

iTrader: (17)

remember, LQ4's are lower compression and cheaper, if you want to eventually boost it on the factory shortblock, LQ4 is the way to go. Even if you do not boost it, with the swap basics (stand alone tune, headers, some sort of CAI, !emissions) the motor will make impressive numbers. If 500hp street only HP is what your after find an LQ4 for about $1500, put rod bolts in it, cam it, valvetrain, and search for a used truck magnacharger. They go on ebay for 1500-2500 routinely. Also the good thing about a Radix is they eliminate the truck intake and add 42lb/hr injectors. That should put you where you want to be.

SheldonZ28

iTrader: (4)

Though im by no way an expert.

Heres my opinion:
a LQ4 short block is MORE then capable of handling a 150 shot. To be 100% sure you wont have any issues, Put in some ARP Rod bolts, and Stud the mains (not sure if LSx main studs are avaliable?). From what ive learned, normaly a crank will fail in an engine from a NOS shot due to flex. The violent burning of the N20, shocks and moves the mains, allowing the crank to flex and break. Aslong as the main's aint goin nowhere, you should have no issues.

Btw: iron blocks are only 60lbs heavier then an aluminum block. Delete the a/c, toss on a fiber hood, aluminum driveshaft, and clean some usless stuff out of the interior, and we are even.

L92 heads are truely amazing for the price. 320cfm @ .600 flow for $899 for the set, is hotrodding GOLD.

My Vote, call LKQ wrecking yards and ask for a LQ4 engine, generally around $1000 - $1500. Toss on the L92 + L75 intake for another $1500. Dump a $400 cam in. And ta-da. $3500 tops, and bumpin 500hp. Definately driveable. And you have the re-assurance if something goes a bit wrong in the engine, it wont be hanging outside of the block that quick. Also iron blocks WILL stand up to more power.

Also, in the future, you have the option of stroking it.

IMO, LQ4's are tonnes of power, waiting to happen.

V8Rumble

iTrader: (9)

Ehhh, I don't know about that, myself. Personally, I'm really glad you posted this, because I'm in the planning stages of my own LQ4/9 swap into my '89 GTA (& I've subscribed to this thread in the hope that a lot of good info gets posted here). My own plan has been pretty much the same as your "1B" - I figure that I may not get much for the old truck parts, but that's just part of the cost of upgrading.

To answer the questions you've posed (from what I've read), the L92 heads will flow more than enough to make around 500 hp, so most of it depends on the cam you select, & how good the person is who does your tune. Is 500 hp possible w/ that combo? Hell yeah!

Then you asked "In all scenarios above, I've been looking at the L92 heads, along with the L76 intake. Are there more affordable ways to get the kind of power I want?" To which I'd answer "I REALLY doubt it!" The L92 heads are supposed to go for about $1000 when dressed up with the offset rockers & other stuff needed, and to put that in perspective, I'm going to be selling a set of brand-new, never-installed AFR 195s that flow less, but cost me $1300, so that I can do this engine swap. And the AFRs are pretty much top-of-the-line heads, my original plan was to build a kick-*** 383 - until I realized that it just couldn't begin to compete with the LQx & L92 combo.

The one part of the picture that I'm really concerned about though is the intake - from some of my reading, people are saying that they're seeing a fair bit of vacuum in the L76 intake, which is seemingly indicating that the intake manifold is pretty much maxed out - has anyone else heard this? And is anyone aware of any aftermarket mfr with plans for an intake manifold for the L92 heads?? Seems like it'd be kind of a PITA to try & make a single-plane w/ a carb TB work, while trying to fit all the sensors & everything...

(Or, to put it a different way, does anyone know at what power level the L76 intake manifold "hits the wall", or how many CFM it flows??)

EDIT: OK, looks like in this article, it flowed enough to make almost 550 horsepower, which is plenty enough for me - if down the road I feel the need for more than that, I guess I'll get some sort of power-adder...

Jim85IROC

iTrader: (6)

Looks like I'm getting some good feedback here. I do have another question for the sake of clarification... some have said that both an LS2 as well as the LQ4/9 can handle a 150 shot... I never really doubted that. What I'm asking is whether one can handle a 150 shot when I'm already at the 500hp level. To me that's asking a lot more of a stock rotating assembly than a 150 shot on a motor that's still at the stock horsepower level.

Jim85IROC

iTrader: (6)

Getting a complete, high milage LQ4 is looking like a good option here. I started figuring out what it'll cost me for a rebuild (at least for the major components) and it looks like I can build a very nice stroker in my $5k budget.

Figure $1k for the LQ4, then:

block machining: 500

stroker crank: 900

SDPC Pistons/rings: 500

bearings: 100

Gaskets w/headgasket: 250

oil pump: 150

timing chain set: 200

L92 heads: 1000

L76 intake: 500

offset rockers: 150

That comes to $5250. This excludes PCM modifications, thirdgen-specific long tubes, installation hardware, and other installation needs like an f-body oil pan, f-body harness & f-body accessories

But, the $5k budget should still cover the major things, and all of the $100 and $200 crap can be purchased on an as-needed basis without too much heartburn. Have I missed any major expenses here ($400+)?

SheldonZ28

iTrader: (4)

id say if your putting in a 900$ stroker crank, it should be more then capable of taking a 150 shot ontop of your 500hp.

Looks like a solid setup. Could be you crack it all open to find it in need of no rebuild.

Jim85IROC

iTrader: (6)

If anything is going to be the weak link here, it'll be the stock rods, but if people are making 500+ on stock short blocks, they should be ok except maybe for during the 150 shot, but who knows if I'd ever even get to that.

I need to see what kind of "under the curve" power guys are making with the L92 heads. I don't want a dyno queen, I want a torque monster of a street motor.