What makes an LS better than a small block?

[axisg]

Bah, the LS vs Gen1 debate again..

Motorhead Mike hit it on the head. Denmah at Sloppy Mechanics has it down to a science for making LS power on the cheap. He builds some radical stuff on the LS Platform. However 1000+ HP and reliability don't go hand in hand no matter what platform you build off of.

I did the math a few years back.
The "typical" V8 Gbody is powered by a SBC. Your average SBC build on pump gas as a DD will be in the 350-400 hp range and will cost appx $3000.00. Nothing radical, just a used "roller block " vortec motor to be freshened, topped with vortec heads, cam, and headers. Drops right into the car and everything bolts back up. Runs on premium pump gas all done in a weekend.

Typical LS would be a JY 4.8 or 5.3, in the 350-450 hp range ( camshaft and springs ), and the average swap price into a Gbody seems to be $3500 to run carbureted and another $1500+ to retain the FI. Factoring in things like an engine controller, mounts, headers ect and doing most of the fab work yourself with a place to do it as it will take time to sort it all out. Runs on pumps gas with better fuel economy, with a broader torque curve.

As I don't race my car and DD it as much as I can it did not make sense to sink more money and more time to make an additional 100 or so hp. The weekend swap and little to no fab work was also very appealing. Aside from the stereo in my car the only electronics is an O2 Sensor hooked to a wide band gauge helping me keep the carb in tune.

If I were racing or felt the need for more power then the newer technology LS Based engine would be key.
EI: Mutual friend is building a twin turbo 5.3 G. Talking back and forth we figure he should hit the 800hp mark with low boost as he wants to keep it streetable and run the stock hood. Last count I recall he said he was over $8k in parts not including the cost of the car or the orig engine. Its been 3 years and it has not moved an inch.

 

[gbodytoys]

There are 3 or 4 videos on youtube that explain, scientifically, how LS motors have advanced over gen 1 small blocks. I believe one of those videos has already been shared here.

There should never be another post on a forum or social media about "which is better" again. Why? because it's been covered, 1,000 times, in depth, and there is not another living human being with a new question about these engines.

These type of questions need a FAQ or something lol. It's right up there with, "which rear end can I swap in my gbody", "what headers fit?", "700r4 or 2004r", etc....

 

[L67ss]

Reasons I will never go Ls. While I'm about performance the engine also has to look good. Nothing about an Ls is pretty. They don't actually fit anything not originally Ls and even in an Ls car there'll be parts you have to switch out. They are a pain to work on. I have never liked how they sound. The few times I've driven an Ls powered ride it was less than impactful. And small/big block Chevy's are FAR from being scarce lol

 

[Opie Knievel]

small/big block Chevy's are FAR from being scarce

They're not impossible to find but depending on where you are, they can be harder to find. I don't think I've ever seen a big block come through here in 3 years.

 

[L67ss]

If you go to a shop that does Ls swaps you can get complete SBC/BBC eng and trans for under $500

 

[Texas82GP]

My take on the LS:

It was designed in the mid 90's based on 40 years of refinement of the Gen I and Gen II SBC. The biggest improvements are the deep skirt block with cross bolted mains, the heads, and often overlooked, the intake. The heads are better because they don't share the Siamese port design of the SBC heads. Are there heads for the SBC that will flow like LS heads, yes but they are high dollar race pieces. The benefit to the intake is that it doesn't have hot water running in it and it doesn't have hot oil splashing on the bottom of it. This helps give the engine a cooler denser charge of air/fuel. Combine the improvements from the heads and the intake and you have a more efficient engine.

Another upside to the 'LS' engine is how plentiful the iron block truck engines are. The yards are full of these engines and they rarely have anything wrong with them, no matter the miles. I've run them commercially well over 200k miles and they run like new. They don't smoke or use any oil.

The downside to the LS is what it takes to make it fit an old car chassis properly. Sure you can get that $600 truck 5.3 and it's a great motor. With a cam and exhaust it will make 400hp pretty easy. However, the truck accessory drive, truck oil pan, truck intake, and truck exhaust manifolds are all compromises when installed in one of these cars. If you jack the engine up high enough to clear the A/C compressor, then the alternator is hitting the hood or close to it. The truck oil pan hangs down too low. You can make it work but its a compromise. You get it in there, now you need a high pressure fuel system to support the fuel injection, you need the ECM and wiring harness. It gets expensive. To really do it right you need an oil pan, headers, LS3 intake, LS3 front accessory drive, stand alone engine harness, A/C relocation bracket and on and on. Once you do all that, it's great. Still, if you run the factory computer/fuel injection setup, now you have to tune it or have someone tune it. That's not the easiest thing in the world We did it on my brother's car. It's great. It was expensive. I won't live with the truck stuff in my car and to do it right is too expensive for me so I stayed with an SBC.

Here's the 20k mile 6.0 L96 my brother bought. It was out of an Express Van....

Here it is after we pulled all the truck stuff off, deleted the VVT, swapped the oil pan, swapped the timing cover, swapped the cam and valve springs, swapped the oil filler spout, swapped the dipstick, swapped the balancer, cleaned and painted it and put on a set of headers that were designed to fit his chassis. We did reuse the coils and plug wires.

Here it is in the car with the LS3 intake, LS3 front accessory drive, Holley A/C compressor bracket, PSI conversion standalone harness, etc., etc......

 

[lilbowtie]

I love reading through post like this. What you are really dealing with are peoples preferences. What makes one better than the other one is simple - decades of development !

 

[ttype]

people who can break in a flat tappet cam have likely been doing it for years without wiping a cam lobe. buying a retrofit roller cam "complete" costs as much as a take-out 5.3 with a 90 day warranty. a set of decent heads for your old motor that can accomodate "your" new recipe-as much as an efi controller. you'll still need to fiddle with a self learning one, but it's a completely different set of tools. overdrive for an older motor compared to the "warrantied" take-out... difference there too. every year that goes by takes the supply OUT of gen 1's, whereas the supply of ls goes up. they've been accumulating for almost twenty years now. i'm all for antiques. i have a big window shortbox to work on next. that one'll be efi all right, but it won't be arriving here in 3 boxes like the last one i bought, it'll come on the next motor i get with a 90 day warranty. if that one doesn't grenade or take anything out with it, my son will get it when i don't need it anymore. upgrade heads for LS stuff is reasonably priced right at your LOCAL gm dealer. go visit the next cruise-in... and ask the guy with a flathead what it's like to find parts for his machine, and how long he has owned it.

if it's going into your daily driver, your fuel costs will be recovered in some time. by the time the ls motor needs work(hopefully a reallly good while at least), a drop-in replacement will still be easy to find.

other peoples' preferences are what influences the way you build your ride.

 

[L67ss]

I keep hearing the roller cam conversion thing.....the majority of TBI and newer SBCs were either roller cam or had provisions for a roller cam. On the ones that had roller provisions but equipped with flat tappet its a matter of a cam swap with about $20 worth of jy parts. In fact I have a complete 97 vortec 350 cam lifter retainer and spider laying around. The days of expensive old style roller conversion are way past

 

[ttype]

I keep hearing the roller cam conversion thing.....the majority of TBI and newer SBCs were either roller cam or had provisions for a roller cam. On the ones that had roller provisions but equipped with flat tappet its a matter of a cam swap with about $20 worth of jy parts. In fact I have a complete 97 vortec 350 cam lifter retainer and spider laying around. The days of expensive old style roller conversion are way past

you are absolutely correct! without a doubt! i went roller cam because i had a high nickel block, and looking around all over the place for a factory roller was beginning to add up in fuel bills, wasted time in phone calls.... LS motors come with a roller cam already was my point. decades of development is the plus you don't have to look for.