My dad has always been kind of a small block guy, despite his recent tendency to choose the biggest engine available in whatever vehicle he buys. I think this goes back to his drag racing days in the 60s, when he was able to enjoy the advantages of a small, power-dense engine in a lightweight car (in his case, it was a ’67 Chevy II Nova SS with a 327, fitted with the cam from the 350-horsepower version of that engine). On the other hand, I’ve always been a fan of the big block. Well, as we all know, the small block has the last laugh (big block production ended in December 2009). Too, small block displacements have grown to meet or exceed legendary big block displacements (the Z06’s “427” (really 428) cubic inch small block tops the 396, 402, and 427 big blocks).
So, it’s a big deal when there’s a new-generation small block V8. GM produced more than 90 million small blocks since 1955 (vs. just 5 million big blocks). As has been the custom since the first generation, the engine launches in the Corvette, then eventually propagates throughout the lineup. Expect Gen V small blocks in the 2014 full-size pickups and SUVs launching next year. Although V8s in passenger cars have become fairly scarce (heck, that’s almost true of V6s!), this new engine family will still find its way into millions of vehicles during its life cycle.
What’s New With the Gen V Small Block
Short of going with an overhead cam design (which will never happen for the small block, the original ZR-1’s LT-5 DOHC engine notwithstanding), GM Powertrain engineers pulled out basically all the stops when developing the new-generation small block. It has several firsts for the Corvette:
- Continuous variable valve timing
- Active fuel management (shuts down four cylinders during light load situations)
- Direct injection
Additional specs on the new engine:
- Estimated horsepower: 450
- Estimated torque: 450 lb-ft
- Fuel cutoff at 6,600 rpm
- Camshaft is NOT cam-in-cam like rumored, but there is a cam phaser
- Cylinder firing order: 1, 8, 7, 2, 6, 5, 4, 3 – just like the Gen III and Gen IV Small Block
- Compression ratio is 11.5:1
- The engine weighs 465 lbs
- Rods are forged powder metal infused with other alloys
- Aluminum block with iron linking design – same as the Gen IV
- Dry sump oil pump will be optional
For a detailed technical discussion of the new LT1, I encourage you to read an excellent write-up by my friend Alex Villani at GM Inside News .
So why stick with the overhead valve pushrod design? Because it works. For its size and weight, this engine cannot be beaten. It’s easy to work on, it has a thriving aftermarket (that’s an understatement), it’s power-dense (with far, far more on tap if you want to modify it), and more fuel efficient than competing engines. GM estimates that the 2014 C7 Corvette will get 26 miles per gallon on the highway. I suspect that we’ll see something closer to 28, because the current car is already rated at 26, and the new engine (with more power) coupled with what we expect will be an even lighter Corvette, with what we expect will have even more gear ratios, should be a screamer. Estimated zero to sixty in the base Corvette is 4 seconds flat. That’s fast, ladies and gentlemen.
A Very Brief History of the Generations of the Chevy Small Block V8
Though there have been just five generations in 57 years, the first generation spanned 48 years, from 1955 to 2003. The second generation, the LT-series, introduced reverse-flow cooling in the 1992 Corvette and a 50-horsepower bump.
The 3rd generation, the first of the LS-series, further bumped power, changed the firing order, and finally shifted the light truck V8 applications to the new generation (the trucks had skipped Gen II).
Gen IV engines built on the Gen IIIs, but added even more power, the ability to have even larger displacements (up to 7.011 liters (427.8 cubic inches) and can include variable valve timing.
The Chevrolet small block V8, first introduced in 1955, has seen more than 90 million examples produced in the ensuing 57 years. That’s remarkable. In contrast, the Tonawanda, NY plant that produced big blocks from 1958 to 2009 built about 5 million.
Those of us at Techshake cannot wait to get our hands on a 2014 Corvette and this new engine. We’ll be in Detroit in January at NAIAS to see the Corvette in public for the first time (January 13 – mark your calendars!) and we’ll share first-hand impressions at that time.
For the full press release, .