What does LS1 stand for?

[RiceEatin2000GT]

Originally Posted by chaos386

If you've seen one of these engines outside of it's car you'll realize why they call it a "small" block. Compared to a DOHC motor, these things are tiny:


^4.6L DOHC on the left, 5.0L pushrod on the right. The real reason, though, is that the "big block" motors from the 60s were 7.5L or more!

heh the only thing is the 5.0L displaces at 302 cubic inches and the 4.6 DOHC is still a small block and displaces at 281 cubic inches so there both still small block motors

[Leppy]

Where does small block end and big block begin then??

[bone]

they overlap

big block and small block purely point to engine design, has nothing to do with the displacement

i think the largest small block is 4.2l and the smallest big block is 3.6l

[bone]

they overlap

big block and small block purely point to engine design, has nothing to do with the displacement

i think the largest small block is 4.2l and the smallest big block is 3.6l

[jneil]

Originally Posted by bone

they overlap

big block and small block purely point to engine design, has nothing to do with the displacement

i think the largest small block is 4.2l and the smallest big block is 3.6l

I would think the largest small block is at least 6.0l...the LS2 is a small block and is in 6.0l format here...My LS1 is a small block and is 5.7l.

[Leppy]

so then whats the differenc then?? Is it just the use of DOHC?

[jneil]

DOHC has nothing to do with it either. I don't really know what the differences are, but as far as I know, no BB's have OHC's let alone two of them and LS1/LS2 don't have them either.

I tried searching for SB vs BB but got so much irrelevant stuff...I gave up!

[Leppy]

haha right o... well.... anyone.... anyone at all???

[bone]

i've asked on another forum, and this is what one of the f-body freaks answered

If you are talking about Chevy BB vs. SB, the differences are obvious - different bore centers, taller deck, larger mains, larger cam (diameter), offset rockers (vs "in a row"), staggered head ports.... many differences to speak to. But they use the same distributor and bellhousing patterns (for a universal fit).

Unfortunately because the physical dimensions are bigger, it is very hard to fit a BB chevy into most cars that were not meant for it - the real problem being radiator clearance and exhaust routing, hood clearance is a problem without a scoop (or tall hood).

In terms of power, yes a BB will make more power than a SB, but there is very little difference when comparing a comparable 427BB with a 427SB. Of course comparing a 509 to a 350 is like apples and oranges.

The one thing that sucks about a BB chevy is the weight. An all iron BB weighs about 100lbs more than an all iron SB, an LS1 weighs 250lbs less in the motor alone, not counting the drivetrain or suspension. So it makes sense to go with a 475hp LS1 instead of a 500hp BB in 99% of the cases, especially where the fit is tight.

I know for a fact that the Dodge SB/SB are very similar in size, the only thing an average person may notice is the BB motor had the distributor in front.

so there aren't really any differences other than the actual physical size of the motor. Big blocks are heavier than small blocks, but will always make more power than a small block of equal displacement simply because the heads are larger and flow better.

[Leppy]

nice. thanks bone.