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LS1 Engine

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powersurg

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I was talking to a friend of mine who has a 98 Vette and he was saying how the 5.3 in the Avalanche is the same as the 5.7 in the Vette. He said that they were both LS1 engines but that the cylinders in the Vette are deeper. He was saying that the Vette had more Stroke but the same bore.

My question is, what would be involved in modding your 5.3 to match identically to the Vette 5.7. I guess one of the items that would have to be replaced would be the Head eh?

What else?
 
Stroker crank shaft, rods, the heads would not have to be replaced, but would need port work, the pistons might need to be notched.
 
Thanks Ed,

1) In terms of Price, what are we looking at (very rough estimate)?

2) Is this a viable alternative to installing a 6.0 liter?

3) Would the new work create an Engine putting out 350 horses like the stock vette?

Thanks
 
Intake manifold in our truck is also different as it is designed for more bottom end...

A huge difference is the block itself... The LS1 is an all aluminum sleeved block where our's is a cast iron block ... Honestly the heads flow very similar ... As many guys are running 5.3 heads on their LS1's ...

IMO ... It would be more feasible to build-up the 6.0 ... This seems the better "truck" choice ... If you look at the new SS reg cab concept truck, they use a 6.0 with basically a vette top end ... As does the SSR similar ... The road is half-paved for you already if you run the 6.0 ...

The 5.7 is built for a car ... IMO ... And without looking, I do believe the bore diameter is smaller on the 5.3 vs. the 5.7... Not 100% sure though without looking it up ...

11H
 
Powersurge, you friend has it backwards. The 5.7L 'Vette has a larger bore at 3.90" compared to 3.78 for the 5.3L Avalanche. Stroke is identical at 3.62". The architecture of the two motors are the same but there are many differences. Modding your Avalanche motor to match the Corvette will not be cost effective. Horsepower for dollar it'll be cheaper and easier to go with the S/C.

The 5.3L engine is an LM7, rather than an LS1.

Now if you can find a good deal on a 6L... ;D
 
Great Information Guys. Its funny how much GM and probably other manufactures borrow technology from one vehicle to build another.
I wonder how different automobiles would be if they were all built in their own technology vacuums. For instance, how fast/different would the Vette be if every part was designed specifically for the Vette and how different would the Avalanche be if all its parts were specific to it.

I guess there is no way of getting around the SC. Too bad because the Mid Gate Windows Sticker "Power Plant by Corvette" would look pretty cool on the Avalanche!!

 
Steelheadchaser said:
Powersurge, you friend has it backwards. The 5.7L 'Vette has a larger bore at 3.90" compared to 3.78 for the 5.3L Avalanche. Stroke is identical at 3.62".
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I thought that was the way it was... ;)
 
Powersurge said:
Great Information Guys. Its funny how much GM and probably other manufactures borrow technology from one vehicle to build another.
I wonder how different automobiles would be if they were all built in their own technology vacuums. For instance, how fast/different would the Vette be if every part was designed specifically for the Vette and how different would the Avalanche be if all its parts were specific to it.

I guess there is no way of getting around the SC. Too bad because the Mid Gate Windows Sticker "Power Plant by Corvette" would look pretty cool on the Avalanche!!
Click to expand...

Surge,,,

If you do some researching, you will find that the Corvette has been the test-bed for much of the technology that has gone into the "less powerful V8's" in their other vehicle line ... I think it's the fact that the Vette has some of the best GM engineers and has the budget to get closer to the "edge" ... The edge is then found at that year of technology and is pulled back and incorporated into the trucks, cars, etc ...

Since we're talking about the LS1 series, I will tell you that I have had 3 encounters with the "GM Corvette Club of Engineers" back in 1997 ... The LS1 was the first of the GEN III V8's and it was well-within the plans of GM at the time to take this push-rod refinement to the trucks ... In their history, I don't believe there has been this much design carried over to a truck ... I believe that the money invested in the LS1 (re-designing the production push-rod V8 small-block from the ground up) has been a huge benefit to GM and us as consumers ... It seems as though they have mastered the highly refined V8 smallie in a push-rod design ... It just shows in comparison to other's V8's with the linear Torque and HP curve, fuel effeciency, and smoothness ... Ford's 5.4 and 4.6 "Triton" (Or Cosworth-like design) hasn't achieved the levels that GM has ... IMO ...

I think the Gen IV will still be a push-rod design going forward, but Gen V, I would like to see some of the old Cadillac OHC/Northstar and new Cadillac car tech go into the mix ... That Northstar engine is an engineering marvel capable of some huge HP in stock form ... From what I gather, the 32 valve actually shares some minuscule technology with the ZR1 Vette engine (LT5) that was co-designed with Lotus ... :eek:

And since we're on the LT5 subject, that was an engineering marvel back in 1989 and was a serious power maker of it's day with 4 valves per cylinder ... Now we have the Z06 engine (a tweaked to the edge LS1) which is only a 2-valve motor eclipsing and now passing the power levels of the LT5 ... With a ton less complexity and with much less emissions ... >:D

11H
 
Powersurge and 11H,
Wouldn't there be some issues of concern regarding the transmission if you were to bump up the AV to 350+ HP? There were earlier discussions on the board about how fragile the 1500 AVs transmission can be - that it was an "off the shelf" part that was marginal at the 5.3s torque and HP rating - and - that while it can take normal use, that it cannot handle much else.

This is more of a layman's question, as I am in no way an expert. I think it would be great to drop an EXT engine /Transmission combo into the AV - or alternatley the 6.0 if the transmission bolts up and will handle the extra torque.


Thoughts??
 
I dont think you would have problems with the tranny if you were pumping out 350 horse at the rear wheel. There are guys here with super chargers installed pumping out more and I beleive they have the stocl Tranny. I could be wrong.


As for all the other posts since my last. You guys know too much!! Thanks for the great info!!
 
I don't want to ruffle any feathers but here is my opinion:

$4K is alot to pay for a supercharger kit, and a stout 400HP chevy V8 could be built for less even if you had to buy the block and heads from a junkyard. I do understand that 400HP at the crank is not the same as 400 at the wheel, but this statement is to get you guys thinking. I have built many motors in my past, mostly Pontiacs. Including the cost of the block (42:cool: and heads, crank, rods, and all accessories and machine work, I spent 7700.00. That engine in an 81 Regal dynoed out at 650HP without Nitrous. (Only babies suck on bottles!) I built that motor to be a torque engine and torque was above 800 if I remember correctly. It did only get around 3.5 MPG. The point is if you take the cost of the block and heads (1,000) out of the equation the cost was under 7,000. That cost is to build a Pontiac, which is much more expensive than a Chevy to build. The Offy manifold alone was 650.00! Additionally, over 500.00 was spent to make it look good, which also wouldn't be relevant to the Av. I feel that I could build an engine for my Av for under 4K that would easily out-torque and out-power the S/C 5.3. The only glitch would be emissions testing. Finally, if you were to buy a performance oriented S/C instead of a vehicle or application specific S/C, the cost would actually be less, closer to 2500 to 3000. Mileage will stink, but the AV would scream!!!!!!!!!!!!!!!!!
 
The only glitch would be emissions testing.
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You said it ... There's the justification for the SC over the "built motor" ... Stock emissions components are kept and truck is still emissions compliant ...

11H
 
Except that in some states vehicles classified as trucks do not fall under the normal emissions reuirements. Also, some states even allow for engine replacements and the vehicle is then only required to meet the emissions for the model year of the engine. Unless it has been changed, Illinois was like this.
 
Steelheadchaser said:
Now if you can find a good deal on a 6L... ;D
Click to expand...

I know that this link worked last week...but today it's acting funny. This site was offering brand-new surplus 6L and Duramax engines. The 6L were going for $1900, and the Duramax was somewhere around $6k, but I don't remember exactly.

http://www.partspit.com/

Mike :B:
 
Posted by: funkypunnk Posted on: 09/23/03 02:57 PM
Except that in some states vehicles classified as trucks do not fall under the normal emissions reuirements. Also, some states even allow for engine replacements and the vehicle is then only required to meet the emissions for the model year of the engine. Unless it has been changed, Illinois was like this.
Click to expand...


Here's something I wrote in an earlier thread that will add some info to the topic you mentioned about "building an engine would be cheaper than a blower add, and as powerful" ... Yes, some states have different emissions laws, but if your engine you build for the avalanche doesn't have all the emissions components carry over to the new motor, you will be over the line... Maybe not in all states, but you will on fed ... You could in fact run a 6.0, or the 5.3, and cam it and give it some good compression and heads, but I don't think you would find emissions compliant parts that could match a Radix blower making 130 RWHP+ ... Only about 1/3 of the cams available for the Gen 3 truck motors are emissions legal ...


EMISSIONS and Tuning
-----------------------------

... Finally, I want to touch on emissions since it hardly comes up and it deserves mention ... (I expect some of the folks here to beotch about this one) ... There is something that is called emissions legal and emissions illegal (CARB, EO, or legal Statement required for legal) ... As time goes on, this becomes more of a concern... Now some of the seasoned members may say bahh ... I don't live in an emissions controlled area... Well, fine and dandy Mr. Seasoned... But remember you still fall under the Federal Clean Air Act of 1991 ... Here's a quote that sums it up ...

"Aftermarket parts are legal to use only if they meet certain requirements. In fact, if they do not meet these requirements it is classified as "Emission-Control Tampering." Since the Clean Air Act of 1991, there is a $2500 fine to the owner of the vehicle, and others for tampering with emission sensitive parts. Some examples of emission sensitive parts are ignition systems, engine computers, chips, cams, throttle bodies, air filters, and certain exhaust components."

11H
 
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