Talk:Small-block

Request more detailed definition of small-block engine
I believe the weight, stroke and efficiency of the small block compared to the big block are the defining factors (at least from a historical perspective). The light weight and short stroke of the Chevy 327 corvette engine producing 350 horse power still remains a bench mark for comparison. The torque/power range of the small block is produced quickly and more efficiently than the heavier longer stroked big blocks at the same or larger cubic displacement. I believe this is why the Chevy 350 is termed a small block while the Ford 360 is termed a big block. The Ford 360 is manufactured into a larger heavier block, to accomodated a longer stroke and with a change of heads into a Ford 390. It is more about weight and stroke (efficiency and size) than it is about displacement. Hence the term small block and big block really equates to the efficiency, as below the Chevy small block is even more efficient today to the extent that even large displacements are produced in a small efficient space. It is also accomplished with smaller bore and stroke but in larger numbers - Dodge viper V10 and Ford V10. Here you have eight more strokes per cycle to accomplish the same at 1 rpm.

Carse The C6 Corvette Z06 has a 7 liter (427 cubic inch) engine, yet is considered a small block. Therefore the difference between small block vs big block can't be displacement.

This is a very common question. Could someone knowledgable please describe (ideally in the article) exactly what differentiates small block vs big block engines that reconciles the C6 Z06 427 cu in. "small block"? Thanks. Joema 22:23, 28 January 2006 (UTC)


 * Honestly it's very fuzzy, and it's an entirely internal distinction. GM has two families of engine blocks.  The big block family has a bigger engine block, in external dimensions, than the small block family.  The Z06's engine block has the same external dimensions as the rest of the small block family, from the 4.8L Vortec 4800 through the 5.3L Vortec 5300, the 5.7L LS1, and the 6.0L LS2.  The LS7 just has a very large bore (very large diameter cylinders) with very little space between the cylinders, combined with a very long stroke (the distance the cylinder travels), so it achieves enormous displacement from a compact block.

Just for clarification, in regards to the above section, the statement "the distance the cylinder travels", should actually be stated as "the distance the piston travels inside the cylinder" Randall HS (talk) 11:31, 28 January 2010 (UTC)

>> (Not sure if I am adding this info in the right place<< -- I know that at least for Oldsmobile engines (my particular area of interest), a big block measures 14" between the heads at the manifold base, while a small block measures 12"; thus it is not the displacement, but the block which is big or small.


 * If you look [here] you can see an LS1 (which originally had a displacement of 346 ci) with the cylinders rebored to 4.125" and with a crankshaft that gives a 4" stroke. By comparison, the stock engine has a 3.9" bore and a 3.62" stroke.  This is how the Z06 achieves its 427 ci displacement: same size block as previous engines, but bigger bore and longer stroke.  You can see from the upper picture exactly how little space there is between cylinders with a 4.125" bore on a small block.


 * The extremely close tolerances that are acceptable in 2006 in a sports car engine simply didn't work in 1966 and don't work in trucks today. As a result, in 1966 it took a bigger engine block to achieve 427 ci, because an engine with that little space between cylinders simply wouldn't hold up.  That's where big blocks come from.  GM still uses an 8.1L big block in light and medium duty trucks.


 * Let me know if you have any questions or any ideas on how to improve the article so it's more clear. TomTheHand 00:14, 29 January 2006 (UTC)


 * Thanks, that's a great explanation. At your discretion if you could include the essence of that into the article, I think that would help readers understand it better. Joema 00:20, 29 January 2006 (UTC)


 * Another suggestion -- the terms "mouse motor" and "rat motor" refer to small block and big block, respectively. Not sure what the origin of those terms is, but they are widely used. Suggest mentioning those in the article, as they are synonyms for small/big block. Joema 12:38, 30 January 2006 (UTC)


 * I agree. However, I've only heard "mouse" and "rat" referring to Chevy V8s.  I'm not sure if I've only been reading Chevy-focused stuff, or if they're terms only used with Chevys.  I'll try to incorporate this into the article as best I can, but I'm not all that great at writing in an encyclopedic style. TomTheHand 13:15, 30 January 2006 (UTC)


 * I worked in a paragraph trying to summarize the above info. I'd appreciate any help with it.  In my edit summary I said I'd put it in big block as well, but it doesn't fit as well there and big block links here anyway so I won't. TomTheHand 14:10, 31 January 2006 (UTC)


 * That looks OK. Link to big block at bottom is OK. Did some research and have a few more details (maybe you already know this): All small blocks trace their lineage, i.e, bore locations etc. to the original 1955 265 that became the 283 in 1957.  It has seen many variations -- 307, 302, 327, 350 etc.  The Big Blocks trace their lineage back to the 348/409/396/427/454.  All GM divisions at one time had SEPARATE big and small blocks none of which interchangeable. Don't know if any of this is appropriate to add.


 * Also, I'm adding a few more links. Joema 15:47, 31 January 2006 (UTC)


 * Not sure that all those details are appropriate here since they only apply to GM small block V8s. That information can be found on the pages for the appropriate engine families.  Some links to the other GM divisions' engine families would be very appropriate though. TomTheHand 15:55, 31 January 2006 (UTC)
 * It does not appear that other GM divisions actually maintained separate big and small block families, so their inclusion here might not be appropriate. TomTheHand 16:00, 31 January 2006 (UTC)


 * Understood. I added a few links, also a brief definition of "block", since non-automotive readers won't necessarily know that term. Change it however you see fit. Joema 16:02, 31 January 2006 (UTC)


 * Looks good. I redirected engine block to cylinder block because engine block just said "An engine block is the main part of an internal combustion engine."  I may work on cylinder block some when I get some time, as it's overly technical and I think a casual reader will have trouble with it. TomTheHand 16:16, 31 January 2006 (UTC)

Why the redirect to Chevrolet Small-Block?
GM is not the only manufacturer using the term small block and big block. Chrysler and Ford both use the same terms, and there are others outside of North America using the terms. Redirecting Small-block to Chevrolet_small-block_engine is both inaccurate and fails to provide information to readers on the distinction between a small block and big block engine.

If a small-block article is not warranted or nobody is willing to draft one, then instead of forwarding readers to Chevrolet Small Block, the redirect should be to the V8_engine page which discusses small blocks and big blocks from various manfacturers.

I am hoping to get some feedback rather than making a unilateral change.

TXGRunner (talk) 17:26, 8 December 2018 (UTC)