UTfan01SS

iTrader: (1)

I recently picked up a cheap low mile 04 model LM7 to install in a third gen camaro. What I want to know is it really possible to bore a cast iron block 5.3
out to a 5.7? And can I use the truck crank and rods with stock LS1 pistons?

I have read so much about this subject but I can't find a definite answer, so I'm not sure where to begin. What Id like to do is punch it out to a LS1, install some LS6 heads and nice cam. Would be a perfect budget build for my camaro. Thanks

01ssreda4

iTrader: (96)

Yes it can be done by any competent machine shop, but no that won't make it an ls1.

65ChevyIINova

People have bored them out that big. There are severl threads on here. The 5.3 crank will have to be rebalanced with the heavier pistons.

schnellttz06

The ls1 has a longer stroke as far as I know, so you would need to make sure the piston skirts are the same

UTfan01SS

iTrader: (1)

the LS1 and 5.3L have the same stroke... which is why I was thinking about going this route.

UTfan01SS

iTrader: (1)

Well no, an LS1 has an aluminum block obviously.. but it should run the same and make the same power should it not? Other than having an iron block.

UTfan01SS

iTrader: (1)

Thanks, I'll have everything balanced for sure. I'm hoping this thing runs as good as any other LS1... I'm going to run LS6 heads, LS6 intake with a nice sized cam. Should be a fun car

one fast zo6

iTrader: (490)

iron 347 is the way to go, better then a ls1

speer13

Why would you even bother wasting time and money on this? If the 5.3 is a low mile engine in good shape doing the same upgrades will get you just about the same power as an LS1 or same as....you may be down a little torque after the mods but in the 400+ range for HP and torque I doubt you will notice it

You are talking about using the same rods and crank having to press fit stock ls1 pistons on, balancing the rotating assembly and then machining a block to accomodate this... It sounds like a 1000+ dollars that could be used on a nice cam set up or towards heads... I don't think the 19 cubic inches is worth the money.

UTfan01SS

iTrader: (1)

Why waste time and money on this? Simple... I have a 5.3L in my garage and I'm doing it all right the first time. Once it's finished and installed its done. Ever heard that saying, there is no replacement for displacement?
Thats why I inquired about punching my 5.3 out to a 5.7. So I can run the heads and cam I want to run and make 400+ hp with lots of torque. It wont cost that much more anyway, machine work and a set of pistons. Then I have peace of mind knowing my motor is brand new and will last a long time. That, my friend, is why I'm doing it. Just to be different...

UTfan01SS

iTrader: (1)

I sure hope so!

sweet99ss

iTrader: (41)

Punching it out will cause a lot of pain and is going to be very hard to get everything in spec this way! It won't work!

KCS

iTrader: (20)

I agree, I'm looking to do the same when I get some more free time. I have a set of rods and forged pistons ready to go. Just not sure what heads, or even what to do with it once it's built!

For a performance application, I always prefer an iron block over an OEM aluminum block. Between the stronger iron block and having the cylinders torque plate honed with a decent stone package, I really think there is a good bit of power just in getting the rings to seal better versus a stock LS1 shortblock.

In the case of LS1 blocks, it can also be difficult to find one that isn't cracked.

Gotta be hard on the knuckles too lol.

bww3588

iTrader: (49)

Depending on what you're trying to do, it can be a toss up. The money you save by not searching and forking over the dough for an ls1 block will quickly be eaten up in machine work to bore and hone a 5.3 block, .119 over.

Other than that, the only real down side to an iron block is weight. Which can be made up other ways.

KCS

iTrader: (20)

For sure, but I think the cylinder work itself on the 5.3l is worth power that you wouldn't see with the factory hone. Plus you're talking a fresh engine versus the "low mile" 10+ year old LS1.

UTfan01SS

iTrader: (1)

Absolutely... that is what I'm going for. The weight thing doesn't bother me anyway, it'll still be lighter than the L-98 350 that came in the car. Now I have to talk to the machine shop to see if they would be willing to bore it that far. Once I verify that I'm going to order LS1 pistons, rings, bearings and gaskets... excited to see what I can do with this LM7

cruisin'73

iTrader: (8)

You obviously abide by the "No replacment for displacement" so why not just step up to a 6.0? Use the $$ you will save by not machining and sell the 5.3 I would think it would be a cost wash.

-Another 17ci of displacement
-Same cost
-Same weight
-Over the counter/OEM replacement parts
-TONS of 6.0 build threads to use for inspiration
-Less work
-Less time
-MORE POWER!

I'm not trying to be a dick, but a 6.0 seems to make much more sense.

UTfan01SS

iTrader: (1)

A 6.0 would make more sense. But I already have a 5.3L in the garage, and honestly, 347ci would be plenty. This is going in a 89 IROC camaro btw... But I know what you mean.

cruisin'73

iTrader: (8)

Good point, since when has any of this hotrod stuff been about making sense...we throw cubic piles of $$ and days of time into these cars so that we can break parts and refill the tanks. Obviously common sense left us long ago!

Best of luck on the build!

speer13

I'm not being a jerk or anything, just throwing out some opinions.....Its your project and everyone is entitled to build how they please, I just see to many people that will bite off a project like this and half way through when money or time runs out they wish they would have just got the car/project together.

You contradict yourself a few times here, you state in the first post you want a budget build, yet rather than using a low mile engine 5.3 that will more then likely meet your power and longevity goals you want to spend money to build it into a 5.7 liter. In which you are increasing bore not stroke on a street engine which will probably not reap the benefits unless you are installing large valve heads or reving the engine higher to see the breathing benfits of the larger bore... look at dyno comparisons on here with a 5.3 vs a 5.7 with cams and heads they are virtually identical.

I understand the "no replacement for dicplacement" but when asked about a 6.0 you state a 5.7 is enough but a 5.3 is not, when over and over they have proven to make the power? If you are going through the hassel of machining and balancing etc. why not throw a stroker crank in and let her rip?

Then you say you are doing it right the first time, having an all new engine yet you are using the same used rods and crank and using stock LS1 pistons?