New GM small block V8

[Shaun @ Tru6]

From Hagerty below but I want to know is why the exhaust is as shown in the pic? Similarly the spark plug location.

General Motors’ sixth generation Small Block V-8 will arrive for the 2027 model year in two sizes, reckon the folks at GM Authority.

The new motor is set to make its debut in the 2027 Chevrolet Silverado 1500 truck but, as with the Gen-V engine, it will find a home across the range. That could include the firm’s upcoming rear-drive sedans, as well as the C8 Corvette.

GM Authority says that its “sources familiar with the matter” revealed that the Gen-VI small block will likely be offered in two capacities. A displacement of 5.7 liters will be the entry point, with a 6.6-liter motor as a flagship. The current small block comes in five flavors: The 5.3-liter L84, 6.2-liter L87 and LT2, 6.6-liter L8T, and a supercharged 6.2-liter LT4.

According to the report, the next-generation engine will make incremental improvements in efficiency without a dramatic overhaul in its engineering. GM President Mark Reuss has promised a four-to-six percent improvement over the latest models and a 10 to 12 percent uptick compared to when the Gen V small Block was introduced in 2019.

GM Authority believes that the Gen VI V-8 will stick with its 90-degree vee and pushrod setup, but when pressed, GM itself would only confirm that the small block will live on. “GM has shared that there will be a sixth-generation Small Block line of engines. No product details have been shared. We can’t comment on speculation,” said a GM spokesperson.

[herr_oberst]

That's the Corvette small block. Mid engine exhaust routing is complicated.

Spark plug location is a mystery. C8 has direct injection, maybe this?

[masraum]

It looks like the spark plugs are just behind each exhaust port in the head, so not much different than normal. Down by the bottom is the coils, with wires running up from the coils to the plugs.

front of motor | O p O p O p O p |rear of motor
O = exhaust port
p = spark plug

And yes, that is the Corvette version of the motor so weird exhaust = mid-rear-engine (think GT40)

[Arizona_928]

Direct injection.
Lots of aftermarket (holly et al.) to convert back to port.

[onewhippedpuppy]

The C8 doesn’t have coil on plug ignition? That’s surprising to see plug wires in 2025.

[Scott Douglas]

For what it's worth, I think the sound of the flat crank V-8's sound like crap compared to a well tuned 283/302/327 SBC.

Just one person's opinion vs millions of others I'm sure.

I'll see myself out now.

Thanks for listening and have a nice day.

[masraum]

Originally Posted by Scott Douglas

For what it's worth, I think the sound of the flat crank V-8's sound like crap compared to a well tuned 283/302/327 SBC.

Just one person's opinion vs millions of others I'm sure.

I'll see myself out now.

Thanks for listening and have a nice day.

I've never heard a "bad" sounding V8, but yeah, I'm partial to old school. But I wonder how much of the sound is exhaust vs engine design. I'd like to hear side by side comparisons that aren't just cars sitting and being revved, but include drive-bys.

[Zeke]

Originally Posted by onewhippedpuppy

The C8 doesn’t have coil on plug ignition? That’s surprising to see plug wires in 2025.

Something is not right. But I think you are.

[Shaun @ Tru6]

Corvette Spark Plug Wires (Set) - Granatelli Motorsports High Temp Silicone Jacketing 8mm "0 ohm" : C8 2020- 2025 LT2 Corvette

It is funny that the set is cheaper than a set of 6 for an '85 911.

[masraum]

Originally Posted by onewhippedpuppy

The C8 doesn’t have coil on plug ignition? That’s surprising to see plug wires in 2025.

Maybe coils right next to (up against) the exhaust is worse than a short spark plug wire.

[vash]

18436572?

[rfuerst911sc]

If used in other models I hope they get rid of cylinder deactivation ! Unless GM enjoys class action lawsuits .

[onewhippedpuppy]

I’ve never found the LS to sound particularly awesome. It’s a V8 and doesn’t sound bad, but there are many that sound better.

[Otter74]

Originally Posted by onewhippedpuppy

The C8 doesn’t have coil on plug ignition? That’s surprising to see plug wires in 2025.

You can’t package COP next to the exhaust manifold like that. There isn’t room, and the heat would really shorten the life of the coils.

[herr_oberst]

Originally Posted by Otter74

You can’t package COP next to the exhaust manifold like that. There isn’t room, and the heat would really shorten the life of the coils.

Coil packs have been located on the valve covers for years, but I wonder if Chevy put them on those towers on the C8 to get them out of sight.

[Por_sha911]

Why show the exhaust? Equal length exhaust headers is a performance plus.
Plug location may requires pulling the motor to get to them?

[onewhippedpuppy]

I will say that while the LS platform is undoubtedly one of the best engine platforms ever, the sound is mediocre compared to the Mustang OHC V8s. This morning a nice older GT with the 4.6L cruised past me, with an obvious aftermarket exhaust it sounded excellent. I think the Mustang is probably the best sounding cheap car, or at a minimum the best cheap muscle car.

[masraum]

Originally Posted by onewhippedpuppy

I will say that while the LS platform is undoubtedly one of the best engine platforms ever, the sound is mediocre compared to the Mustang OHC V8s. This morning a nice older GT with the 4.6L cruised past me, with an obvious aftermarket exhaust it sounded excellent. I think the Mustang is probably the best sounding cheap car, or at a minimum the best cheap muscle car.

I had a buddy back in the mid 90s that was a diehard mustang guy that had a bunch of mustang buddies. The late 80s early 90s mustang 5.0 with flowmasters sounded pretty awesome. And Mustangs seemed to retain a good sound for a couple of decades.

[rfuerst911sc]

Is the LS a flat plane crank ? I don't believe it is but I thought the C8's are . And aren't newer Mustangs flat crank ? That certainly changes the exhaust note .

[LWJ]

Two things: 90 degree and push rods.

Living with dinosaurs. Not that this is always a bad thing.