Is the SRT8 6.1 Hemi Considered a "Big Block"?

[SPEDS]

Just curious!


Paul

[SRT8 WOOLF]

no
heres sum info tho
In December 1992 Mopar Performance began production of new 426 Hemi blocks, and since then have added heads, standard bore pistons and other parts so that is now possible to build a "new" 426 Hemi from scratch! The new block maintains the same outward appearance as the original (except for a new casting number), but has a thicker deck for better stiffness and gasket sealing. A pleasant side-effect of the improved rigidity is about 25 extra hp. Main caps are cross-bolted just like the original. Mopar Performance has even produced a version of the block with B/RB engine mounts, so a Hemi can now be dropped into a big block car without searching for an expensive Hemi k-member.

New heads and pistons followed in 1995, and fortunately Mopar Performance thought to see fit to produce a set of heads with hardened valve seats, so they can be ran safely on unleaded fuel. Now the only missing major piece is the original 2-4bbl intake manifold, although a single 4-bbl version is available and is probably more streetable. Of course, there's also a magnesium supercharger manifold available for all top fuel wanna-bees!

Racers and restorers alike have been well-served by the reintroduction of the Hemi. Demand has been high and it looks like the elephant will live on into the 21st century as the king of the asphalt jungle. Way to go Mopar Performanc

Originally Posted by SPEDS

Just curious!


Paul

[RoostKing]

I always wondered what size a motor had to be to be considered a big block. Mopar 383's back in the day were considered big blocks (or mid-block LOL) so I would guess getting around that cubic inch makes it a big block..

[WO51]

The size of the distance between the cylinder bores has led to a distinction between the V8 engine families the Detroit Big Three automakers (Ford, General Motors and Chrysler) have been building since the 1950s: There are Small-block and Big-block engines. These families differ in respect to the distance between cylinder bores, but not necessarily in engine displacement since the latter is defined by bore and stroke.

While the big-blocks have been less commonly used in recent years, the small-block families have grown in displacement and have now reached a level that was reserved for big-blocks in previous years (up to 7 litres of displacement in a Corvette). Even though the technology has greatly changed, basic specifications have been the same for fifty years.

The internet is a beautiful thing... thank you Al Gore.

[Hal H]

The main differances would be cylinder bore spacing and the cylinder wall thickness to allow a maximum bore size.

The old production A block went up to 5.9L (273, 318, 340, 360 CI)

The B block engines were 383, 400, 413, 426 cubes (or 6.3 - 7.0L)

The RB blocks were 440 and cubes (or 7.2L) these had a longer stroke than the B block.

The 426 Hemi was different enough from the RB engines that it had major differances, including the cross-bolted mains that the B/RB engines didn't have and the staggered valve layout and physically larger valves the Hemi heads allowed.

[340EBody]

The RB was the 413, 426 wedge & hemi, and 440. The 400 was a bored out 383 and therefore a B block. The RB mean't "raised B"....higher deck height. The Street Hemi (426) was essentially a 426 wedge with hemi heads....although there were some differences in casting.

[SPEDS]

So the answer is small block?

[Go Goody]

Originally Posted by SPEDS

So the answer is small block?

Yes, but the HP is = to a Big Block

[425hpChargerSRT8]

exactly. its a small block with the torque and power of a big block. I think it would be considered a big block if it had more cylinder wall thickness, so it could be "over bored" more. Those walls are just too thin

[BobBarry]

"Big"-block and "Small"-block are merely relative terms, dating back to when manufacturers had multiple engine-architectures in production at any one time. It really didn't have any relation to absolute numbers of cubic inches or bore-spacings, and there certainly wasn't any industry "standard" for the designation.

So, if you really wanted, I suppose you could call the current 4.7L V-8 the current "small"-block and the 5.7/6.1/6.4 engines the "big"-blocks of today.

Or not, as the terms are as anachronistic as saying that the 6.1 motor in the SRT's comes with a "3/4-race" camshaft, "Hi-Po" heads and "turbo mufflers."