What is the difference between a small-block and big-block engine?
- Monday Dec 21,2009 02:00 AM
- By diddy
- In Others
The new LS7 engine by GM (in the Corvette Z06) is 427 cubic inches. Why is this a small block when the previous 427 was a big-block engine? What is the difference in the set up of the engines? I know that the cylinder bores are bigger in the new engine and the connecting rods are titanium, but what is the difference between a small-block and a big-block engine?
So what I am gathering from other websites is that classifying either a small-block or a big-block has nothing to do with displacement, but the distance between the middle of each bore. So is there a specific distance between the bores that classifies the engine as small-block or big-block? And note to the GM ASE ceritified person that answered: every website that I have looked at (rssportscars.com, wikipedia.com, superchevy.com, gmgoodwrench.com) all say that the LS7 is a small-block engine that uses the same architecture of a LS2 engine, just a larger bore and a longer stroke.
Architecture, Ase, Bore, Connecting Rods, Corvette Z06, Cubic Inches, Cylinder Bores, Displacement, Gm, Gmgoodwrench, Ls2 Engine, Ls7 Engine, Stroke, Superchevy, Titanium, Wikipedia
One Comment
Essentially the only difference is the physical size of the block itself. The 427 refers to the capacity of the cylinders. In a small block 427 the cylinders will be closer together. This can cause overheating problems, which some people don’t care for. However, parts for a small block engine are less expensive and more readily available than those for a big block.
There are several overlaps between the small block and big block engines in Chevy’s history, for instance, the 396 big block, whereas the 400 is a small block.
Hpe that helps you some!
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