csmc711

iTrader: (4)

I have a iron 5.3 and the legendary infamous LS1 5.7 status symbol keeps luring me to the dark side. I want a 5.7 to say I have a LS1 but the bores look really good, albeit a little rust around one of the top of the cylinders that should clean up with a hone.

So, I know the 5.3's make decent power, but, since it is a used engine, is it worth spending the money for new pistons and getting it bored?

Mavn

iTrader: (3)

If you're going to forge it . I'd do a forged iron 5.7. If not. Don't worry about it ..

farmington

iTrader: (14)

or look for some nice, used 5.7 pistons. you can usually pick them up cheaply

Know It All

I'd say go for it. I'll take 20 more cubic inches and more bore area any day!

Darth_V8r

iTrader: (4)

What heads? If you're going to do some porting work or move to 243/799's or both, the extra bore will make a very big difference. If you're keeping the stock 706's, they don't flow very good, but your compression would increase some. After boring it out, you'd be able to run a bigger cam, larger intake, more mods, more mods, and next thing you know, you wake up in a ditch with an eye patch.

Overall, I'd say yes, it's worth doing. If you have plans for future mods, you'll be in better shape to take advantage of them.

thunderstruck507

iTrader: (18)

If you are disassembling the engine anyway and can get used parts cheap or intend to put forged in it sure.

But it's still an iron 5.7, not an ls1. An aluminum block is a big deal...108lbs worth of big deal last I looked in the sticky above.

Darth_V8r

iTrader: (4)

That's funny. I was just checking on this thread, because I had thought - "Why not just pick up a LS1 short block, save some work, AND get a 5.7L?"

csmc711

iTrader: (4)

I have 2 sets of 799's and a few 865(?)'s so I have some choices.

Oh, and I have already ended up in the ditches a few time but seemed to have avoided the eye patch's



I have a plethora of choices running around in my head. I have 2 cars getting the LSx transplant. I have a grand cherokee getting one and a E36 getting the other. I am torn between what to put into them. E36 was originally thought out with a 6.0 block fresh from Summit or somewhere and build on that for the E36. Then, I was like why pay $1k for a 6.0 when the LS1 5.7 isnt much smaller than the 6.0 and gets better gas mileage. then everyone is saying the 4.00 bore is better, bla bla bla. Fast forward to picking up 3 roached motors for $300. 1 rebuildable steel 5.3 motor, just needs cylinders hones, havnt seen the crank, and, 2 aluminum 5.3 DOD engines. One has been sanded by metal to the max bore size (which will be used for mockup for the time being) and the second "may" be salvageable. I grabbed them for the crank and rods mostly. So, stay with the 5.3 on the cheap or drill it out for 5.7? If I go 5.7, who gets that, the truck or car, lol? do I put the other 5.3 in the vehicle that gets sloppy seconds or still get that 6.0? If I go 6.0, does the truck that pulls and plays get the HP or do I put that in my daily driver for a screamer? Ahhh, decisions concision.

Right now, I am just wondering about the iron block. Some say to bore it to a 6.0, but, would be nice to be able to rebuild it twice if needed and not gouge it out all at once. Then again, I dont think I can go past 5.7 because it is not a 5.3/5.7/6.0 block. But hey, sometimes you gotta do what you gotta do.

Darth_V8r

iTrader: (4)

I'll give you a theory on the 6.0, and you tell me what you think. There is nothing magic about iron vs aluminum. The iron block weighs more, but not 10 mpg worth more, right?

So, here is a quick thought experiment... LS2 vs LQ4. I had a LS2 get me almost 30mpg highway in a manny tranny corvette. 22 around town. The LQ4 gets like 12 mpg, 14-16 on the highway. The LS2 has 64cc chambered 243 heads and consequently very high compression. Compression = efficiency. The LQ4 has 317 heats with 74cc chambers and consequently lower compression = lower efficiency. Now, look at the LS3 that is a 6.2 L with an even bigger bore and gets decent mileage in a Camaro.

So, in my orange truck below, I mated an LQ4 block to a set of 243 heads and a LS2 cam, intake, and shorty headers. Effectively making it an iron LS2. No DOD, not VVT. Nothing crazy, right? Gets 22mpg mixed highway and city. 19 city only. 25 cruising. Now, it is an S10, so it weighs less than my dog, but I do think that getting the compression up in the mid tens and giving it an LS2 top end contributed to the mpg as well.

All that to say the 6.0 isn't bad from being a 6.0. I suspect it was inefficient due to lower compression - maybe GM did it to help it run cooler, I don't know.

If it's me, I'd put the bigger motor in the truck if I was using the truck for towing and hauling. Basically, whichever vehicle I planned to use for showing off would get the better motor

Darth_V8r

iTrader: (4)

now my showoff car is the TA. my next plan rhymes with "408". maybe you can figure out what I'm going to do next from that clue...

csmc711

iTrader: (4)

What do I think, hmmmm....

I wanted to get a new blazer and ditch the cherokee since they have drop in parts for a 6.0. Upon researching, blazers have a full frame. Comparing the curb weights, the blazer is 600lbs more than the cherokee. I could only assume the corvette is lighter than the cherokee, so, we will add 200lbs to that. Now, being that the s10 has a full frame like its big brothers, your pushing around an extra 800lbs give or take if you just ate a big burrito sandwich or not. As a final note, the aluminum is 80+ lbs lighter, so, add that in also. Not much more to make it a special block over the steel, but, it is extra weight none the less. Now, to save gas money, is it worth $1k (price of a summit/GM block) to save fuel? Probably not, but, if I am going to put it inot my car, then, maybe. Truck not so much. All that could count for a good 5mpg diff.

Now we get into the speculation part. I really wish someone would (since people just like to experiment anyways) take a 5.7 and a 6.0 and compare them. starting with a block only, set one up with internal goodies, run it and swap ALL the internals out (except for balancing) and put it into another. That includes making sure the pistons weigh the same. They share the same stroke, so, all timing, cam and sensor positions will remain the same. The "only" thing that has changed is the bore size. Now, run that on the street doe 20k miles and compare the results.

They are close, so, no computer tuning would be needed if you use the same injectors. Were not talking about racing here, so, I dont think anything bigger than stock 5.7 is needed, and, if so, just go one size higher.

Next would be the computer. Again, all perams could be the same. Since it is a MAF setup, the MAF will tell the computer how much it is breathing. Tables can stay the same because they are only used for open loop tuning for the most part.

Other than the above, engine to engine comparison is nothing more than speculation of common sense, but, no proven facts, just a lot of sht talking. Sure, one can never know with separate computer, different heads, diff cams... Would be logically impossible to compare. If it walks like a duck and talks like a duck, locical common sense would say it is a duck, or, in this case a 6.0 uses more gas than a 5.7, but, and here is the big "but" (and not my ex gf's big butt) .......... Everyone I have talked to that has a 6.0 in a truck or car says "she is fast but uses gas!

With out actual comparisons, makes me say really? Why? Why is everyone having such a gas crises with these things, lol???

gagliano7

You aren't doing a fair comparison with a ls2 in a corvette and a LQ4 in a truck. Put the LQ4 in the vette and you will have almost identical mpg's as the LS2.

Darth_V8r

iTrader: (4)

I had thought someone would say that when I posted. I agree, it isn't a perfect comparison, but I don't think it's true that a LQ4 would get the same MPG in a vette as an LS2, because the compression is lower in the truck engine. Compression is efficiency.

LQ4 = 9.5:1
LS2 = 10.9:1

I'm guessing GM decompressed the LQ4 to help it run cooler for towing, but that is a complete wild guess.

MillsMotorvation

Great ?? Im doing one now. Forged rods, and pistons. 6.0 crank! You dont want to know how large the turbo is! Good luck!

Blazeracer

iTrader: (2)

Doing what? A 5.3 to a 5.7? Cause I have a 5.3 block and set of 5.7 forged pistons and rods that I'm thinking about doing this to also. Unless it's a 4.8, an LS7 or a stroker, the cranks are all the same. Putting twins on mine.

dawgs74

what would an lq9 be with 64cc heads?

2ToeRacing

iTrader: (5)

Can a 5.3 iron block be bored to 6.0??

StorminMatt