Hot Rodding a 5.3L vortec

[shanekennedy]

LS1 nor truck intake out flows the LS6 intake in the upper RPMs. It simply doesn't happen. Midrange and low end sure they are close.

so the question is, how much time does the initial poster plan on spending in the upper rpm range

[WS6]

True, if the driver simply doesn't care to run it up there then there's no need for it. But it's easy to get up there and if you change cams you'll most likely be leaving power on the table by not going to a car intake

So I forgot to measure today. Got tied up and didn't get as much done as I had hoped. I'll try to get a measurement from the crank centerline up Friday. The engine is sitting in the car, but I can easily get to it.

[00fxd]

I may hit 6k or better on occation Wouldn't the 5.3 be less suseptible to the limits of the truck manifold than the 6.0 ? Providing of course that they are both the same pn# which I think they are .
WS6 no rush on the measurements . If you are able to get measurements of both truck and car arraingments that would answer some questions for me . Thanks again .
Frank.

[g-roadster]

If I remember correctly the truck manifold is about 3" higher than the Corvette manifold. If you don't get a better answer by tomorrow I can measure mine. If you go for the lower manifold you will need a front outlet Corvette/Camaro water pump vs the top outlet truck water pump. This pump has a different pulley location so you need a new engine harmonic balancer, and brackets for the power steering pump, generator and AC compressor. For your Corvette installation you will need more ground clearance so you will need a Corvette oil pan. You will have a 327 engine with the 5.3, or close enough.

I am using the 5.3 aluminum engine in the g-roadster and will be making the above modifications. I got a brand new aluminum 5.3 from Schram for $1700, thanks to shanekennedy for the tip. It will still be cheaper than a well used Corvette engine. By the way it came out of a Buick, can you be cooler than that?

[andrewb70]

The 5.3L aluminum engines are a bargain. I got one with 28K miles for $1K.

Andrew

[shanekennedy]

The 5.3L aluminum engines are a bargain. I got one with 28K miles for $1K.

i don't think most people realize there is an aluminum version of the 5.3, so not much demand.

00fxd, here's a link for you
http://www.performancetrucks.net/for...d.php?t=357424

[g-roadster]

Here are some measurements:
Manifold height from top of block;
Truck 11"
Corvette 6 1/4"
Oil pan from bottom of block;
Truck Buick Rainier 4wd 7 1/2"
Corvette bat wing 4 3/4"

7 1/2" difference in engine height.

Thanks for posting the Speartech solution for the Corvette manifold. The generator will too high for hood clearance on many applications so more work will need to be done. Anyone with a slick solution?

Unless you need the hood clearance it doesn't seem worth it to change manifolds.

[WS6]

I still have the hub and water pump on so getting exact measurements wasn't really possible. With that said, the LS6 intake is approx 16 inches over crank centerline. The truck intake is around 21 1/2inches above crank centerline. Hope this gives you some ideas

[Ricoch3T]

Sounds and looks for for a "lil" 5.3... I thought bout buying one off of the guy in the for sale section myself for a street rod project I'm working on but I can't decide if i want to find one of those FI 454 big blocks out of the older SS trucks or not. I'm more familar with small blocks but a big block in a big car sounds better to me

[BonzoHansen]

The 5.3L aluminum engines are a bargain. I got one with 28K miles for $1K.

Andrew

Are the blocks (ignoring manifolds, accessories, etc.) the same, externally (mounting holes, etc.)? I was told there are subtle differences.

[00fxd]

That helps a lot ! The top of my air cleaner is 19" over the crank and I have a few inches under the stinger so just about anything should fit .
Thanks all . Good thread .

[Madspeed]

Sounds and looks for for a "lil" 5.3... I thought bout buying one off of the guy in the for sale section myself for a street rod project I'm working on but I can't decide if i want to find one of those FI 454 big blocks out of the older SS trucks or not. I'm more familar with small blocks but a big block in a big car sounds better to me

Im A big block guy myself. But the fi version is NOT what your looking for. The heads SUCK
You will notice I built a 496 with all the goodies @ a hefty price of 12k and sold it
for 13k or so you can get an LS7 500hp Corvette eng
Or build a NASTY LSX makin 600hp +
LSX is stronger and Lighter

Now Im waiting for the new Iron LSX perf block to start my 1.5k + hp Twin turbo LSX

Its very easy to get 500 hp out of any of the LSX engines these days with the right parts
you cant beat a set of truck heads direct from gm that flow over 300 cfm right out of the box for 800 bucks

[andrewb70]

Are the blocks (ignoring manifolds, accessories, etc.) the same, externally (mounting holes, etc.)? I was told there are subtle differences.

I own one and I see no differences, yet. If you think about it, there is no motivation on GM's part to make subtle differences in the blocks. The 5.3L aluminum block engines are not only used in TrailBlazers and clones but also in some Silverado 1500 pick-ups. Do you know what the "subtle differences" are supposed to me?

Andrew

[Ricoch3T]

Wow I didn't know that, the ones I've seen in the older 454 ss trucks seemed pretty potent, but I've never owned one, or done a lot of research on the subject yet. I'm trying to finish the camaro up first before I get started on the next project . For the same cost I'd rather go with a small block anyway, I'ma small block guy anyhow...
On another note I havn't looked into the 5.3L myself but if the block is the same as the 5.7L you could probably up the bore or stroke to make a 5.7L. I can't remember the specifics on it but I think its closer to what?? 327cubic inches? I don't know what the bore/stroke is on the 5.3.

Edit... I found it
http://www.mortec.com/borstrok.htm
325 = 3.779" x 3.622" ('99-later, Gen.III, "LM7", "LS4 front wheel drive V-8" 5.3 Liter Vortec, 6.098" rod)
345 = 3.893" x 3.622" ('97-later, Gen.III, "LS1", 6.098" rod)

Same crank and rods bigger bore. I'm sure the heads are a little different but I'm not familar with the LS1 and vortec heads.
Are there any block differences between the two?

Im A big block guy myself. But the fi version is NOT what your looking for. The heads SUCK
You will notice I built a 496 with all the goodies @ a hefty price of 12k and sold it
for 13k or so you can get an LS7 500hp Corvette eng
Or build a NASTY LSX makin 600hp +
LSX is stronger and Lighter

Now Im waiting for the new Iron LSX perf block to start my 1.5k + hp Twin turbo LSX

Its very easy to get 500 hp out of any of the LSX engines these days with the right parts
you cant beat a set of truck heads direct from gm that flow over 300 cfm right out of the box for 800 bucks

[00fxd]

I am also traditionally a bb guy myself and have owned several in street rods etc . I have heard enough about the LSx engines now to jump in with both feet . There is the vortec 496 , I saw one on ebay recently but it is all cast iron . This all aluminum stuff appeals to me .
Madspeed, by "Truck heads" you mean the 317's ?

[andrewb70]

I am also traditionally a bb guy myself and have owned several in street rods etc . I have heard enough about the LSx engines now to jump in with both feet . There is the vortec 496 , I saw one on ebay recently but it is all cast iron . This all aluminum stuff appeals to me .
Madspeed, by "Truck heads" you mean the 317's ?

There are lots of truck heads. The 317s are 6.0L truck heads. I think Madspeed might have been talking about the L92 truck heads. As noted before, these won't fit on a 5.3L. L92 heads need at least a 4.0" bore.

Andrew

[Ricoch3T]

There are way of dealing with bore size

There are lots of truck heads. The 317s are 6.0L truck heads. I think Madspeed might have been talking about the L92 truck heads. As noted before, these won't fit on a 5.3L. L92 heads need at least a 4.0" bore.

Andrew

[trapin]

Hell I got a 5.3 in my '02 Silverado and I think for what it is it's probably the most atheletic engine I've ever owned in a new vehicle. I can just imagine what I nice camshaft, intake and ported throttle body would do to it.

Be fun I bet.

[WS6]

00fxd sounds like you may be cutting it close. So don't drop the hood the first time you go to shut it. Also don't forget about the motor torquing up. I measured to the top of the intake but the mount for the ugly engine covers was still on there. You may have to remove that on your intake in order to get the hood to fit. If it doesn't work out you can always switch to the car intake and acessories. We know the engine itself will fit.

[BonzoHansen]

I own one and I see no differences, yet. If you think about it, there is no motivation on GM's part to make subtle differences in the blocks. The 5.3L aluminum block engines are not only used in TrailBlazers and clones but also in some Silverado 1500 pick-ups. Do you know what the "subtle differences" are supposed to me?

Andrew

Nope, I asked because I basically heard hearsay. Not even specifics. A guys yapping at a show. He said accessory mounting, but I'm betting it was just accessories themselves.