I don't want to come across sounding like a dumba$$, but how does an LS1 make the 300+ horsepower it does?

1. Look at the cam specs for a 2002,
197/207 int/exh @ 0.05" duration
0.467" / 0.479" int/exh lift
116 LSA
By conventional SBC wisdom, this is a wimpy cam. And sure as hell not ment to power an engine to over 6000 rpm

2. The heads have an 200cc intake. This is nuts. On a SBC, this would be the type of head to rev an engine into the 8000 rpm range, and not idle very well. Yet the LS1 purrs like a kitten.

3. Again with the heads, they will flow almost 230 @ .600 on the intake side. Looking at SBC heads, these would be serious performance heads!

So you see, when you think of the parts combination you would use for a SBC buildup, what the LS1 uses doesn't make any sence. This would be one jacked up SBC, yet its one nice LS1 motor. So what gives??? Is it the longer stroke? Better ignition setup? What?

 

heads are number one to making power. Cam is not.

Its more then the intake runner CC---its the whole design--some one can add to what I am trying to say.

The intake flows very well too. Designed to perform at high rpm--TPI was never designed for that.

LS1 (or LS# insert number there) are just the latest pushrod technology.

EFI has advanced so much through the years and this is the culmination of all that learning.

 

avro is sorta right... it has allot to do with the LS1 heads they will out flow most other LSX heads and the cam you cant believe that chevy just walked into a stock room and pulled that cam off the shelve and said good enough do ya? no thousand of dollar in testing and research was probably poured into it and is one of the biggest reasons the engine makes its power.... the cam and heads are where its at for power put the wrong combo on even a 502ci and you will stand the chance of being passed by some soccer mom... also the FI system has come along way from the TPI or TBI of thirdgens to sequential injection and complete control of ignition timing on a individual cylinder basis

 

Maybe even hundreds.

SpitotRs is right. Don't place all the emphasis on the cam. The cam only serves one purpose, and that is to open and close the valves. If the heads and valves are sized to flow very well, the valves don't need to be opened a mile. A 1.5" valve at .800" lift won't outflow a 2.20" valve at .400 lift. If they are opened and closed at the correct time and the correct rate, a "weak" cam with good valves in good ports will win.

 

The LS1 is a GenIII small block by Chevrolet.

The head degree/ valve angle also has alot to do with it as well.

SBC - 23* heads
LS1 - 15* heads

SB-2.2 - 13* heads (just for comparison, this is a NASCAR engine that produces 800hp)


Everything is different about this engine. Everything. Firing order, siamezed intake and exhaust design, coil on plug, all aluminum. Like the above two said, the heads have alot to do with it.

 

Not to mention vastly better and more capable computer/engine management.

 

ya its crazy what an ls1 can do, i wish there was a way to do sequential fuel injection on an older small block

 

The design of the LS1 intake ports solved two problems the SBC had...

A) big CC ports kill air velocity
B) small ports kill breathing capacity

They did this by not just making them really big, like they did when they designed the BBC (BBC rectangle ports were just really big SBC ports really). They did it by making them really TALL and NARROW, with a pyramid shaped peak on the roof of the port.

Most of the airflow through an intake port is at the roof, so making it really narrow at the roof really helps to keep air velocity up, and because they are so tall, they have alot of volume, so they can also move a large capacity of air when the engine calls for it. This is actually also the reason for the shape of the intake ports on a Vortec L31 cylinder head. They are taller and narrower than a traditional SBC head - and thats why. Thats also why they work so well. And those old LS1 heads have small ports compared to what GM is using on the Gen III now. The L92 and LS2 heads have 260cc intake ports, and I think the LS7 have even bigger ones.

With a good head design and and intake and exhaust system that work well with those heads (stock F-car LS1 exhaust manifolds flow better than most shorty headers do), you don't need alot of cam to make alot of power.

Even the LT1 and LT4 are actually good examples too.... thier cams were very similar in specs to the LS1 cams, but the LT1 was 'rated' 285hp with that cam, and the Corvette LT1 was rated at 305 with that cam too. The LT4 had a different but similar cam, and it was rated at 330hp.

...And sequential EFI can be done on a Gen 1 engine. You use the fuel system, ECM, ignition system, and sensors from an L31 engine (Vortec 5.7). It uses the same ECM as the LS1 actually.

 

How embarrassing.

Nobody mentioned the 6.098" rods. . .

 

Sure! Just go to www.accel-dfi.com And look at the "Thruster" system. If you use the "Dual-sync" distributor, you can select sequential fuel injection (SFI). This is the system I am using on my latest build. It's not cheap, but it is good!

 

thats pretty cool but it seems like too much messing around and money for me, ill just wait it out till i can buy me an ls1 powered 6 speed ws6

 

or 10 head bolts

 

that's actually a very interesting thread. thanks for sharing all that information. subscribed for further specs

 

One coil per cylinder (coil on plug) gives each coil 8 times as long to recover at any given RPM vs. the standard V8 single coil. As well as shortening the spark plug wire length and eliminating cylinder-to-cylinder stray sparking. Practically takes ignition issues out of the performance equation entirely.

 

I think its all in the Tech. and many hours of engineering work, for instance there is a guy from my home town with a all motor LS1 that run 9 seconds all day, no turbo, no super charger, and no NOS. just head and cam work. Those motors are just a Beast

 

So basically, GM has mastered the design for the heads, and intake. Along with superior ignition and fuel timing. With that, they can get away with a wimpy, fuel economy, smog frendly cam and still obtain great power. I guess thats why I've head of going from 300 to 400 hp in these engines with just a cam change, and still run smooth. Nice work GM, just wish we could do this to our older 350 SBC's.

 

YOU CAN!
not really though, World makes a block that is really just SBC and uses LS heads, designed for vehicles whioc are alredy equippd with sbc, so no need to make mounts. also uses sbc oil pan, dist, fuel pump, and all accesories, eliminating the need to source ls accesories. it will take up to 4 in stroke without clearancing, use 400 sbc crank and internals, up to 4.185 bore.
oh and thre newer LS3 flow in the 330cfm range. ported go to about 350cfm. some really good porters have got them flowing 370cfm
(Greg Good)

 

i just wish i could afford one better yet the labor to get one installed and all that other stuff you need for it to run