Chevy LT4 small block is a torque monster

Chuck_thehammer wrote:
same reason the "409" was not a good anything engine.... died 1965...

mainly the engine block... keep crankshaft in line.. and keep head bolts from being pulled out..

and the reason there were (2) 427 engines..

427 Tall block (Truck)
427 standard block (Car)

The 409 was a good engine for it's time. It was a hard running drag engine that won some National championships. It was also a well regarded high performance, street engine and used in medium and medium heavy truck applications.

I emphasize for it's time...if you look at criteria such as engine durability, power, torque, noise, vibration, harshness...the 348/409 W series V8 was a good engine.

You cannot compare any engines made 50-60 years ago with modern engines. Technology has marched on at a rapid rate...so much so that a modern engine, eclipses decades old designs.

8.1Van wrote:
It would have about 600 ft lbs tq highway speed in OD with a 3.73 rear and 31.5" tire like the LT265/75R-16 with much left over for passing and climbing. At high altitude it would not lose as much power as a non supercharged engine. I bet it could be modified for truck (LT4HD ?)use to lower the high rpm HP but keep the low end torque. The 8.1 has 450 ft lbs tq @3200rpm vs LT4 having over 600 ft lb tq @3200rpm or 450 @1000rpm.

Basically an Ecoboostish V8, only supercharged rather than turbocharged. Torque and hp specs would no doubt have to be rolled back to be able to stand up to a HD pickup duty cycle. 450 hp/550 torque would be pretty doable I would think with an iron block. Towing mileage would be horrendous but you could go about as fast as you want. Still would be hard to compete with modern diesels that go over 400/900 with much better towing fuel mileage and good longevity.

Chevy really makes some impressive small block LS based engines. This would be a cool engine to throw in a classic C10 if your upgrading the original drivetrain. It will be interesting what performance goodies that GM does with their HD 6.0 engine in the future. I mean the engine is awesome but I see direct injection within a year or 2.

Chuck_thehammer wrote:
same reason the "409" was not a good anything engine.... died 1965...

mainly the engine block... keep crankshaft in line.. and keep head bolts from being pulled out..

and the reason there were (2) 427 engines..

427 Tall block (Truck)
427 standard block (Car)

It yielded a good song

It would have about 600 ft lbs tq highway speed in OD with a 3.73 rear and 31.5" tire like the LT265/75R-16 with much left over for passing and climbing. At high altitude it would not lose as much power as a non supercharged engine. I bet it could be modified for truck (LT4HD ?)use to lower the high rpm HP but keep the low end torque. The 8.1 has 450 ft lbs tq @3200rpm vs LT4 having over 600 ft lb tq @3200rpm or 450 @1000rpm.

A good ole 8.1 is truly the torque monster

Chuck_thehammer,

Engine technology, materials, and alloys have changed so much since those engines were designed and made. No comparison. The major consideration for any work engine is at what RPM do you want the maximum torque (rotational twisting force of the engine's crankshaft) at?

It's torque that is the force that turns the wheels to any RPM's at all and what moves the load to the desired velocity!

same reason the "409" was not a good anything engine.... died 1965...

mainly the engine block... keep crankshaft in line.. and keep head bolts from being pulled out..

and the reason there were (2) 427 engines..

427 Tall block (Truck)
427 standard block (Car)

I understand that particular engine and the 6.2 aren't heavy duty engines, but why couldn't they easily be? I am truly curious as to why GM can't take the 6.2 with its technology and give it a stronger crank, an iron block etc, and use it in the HDs.

The engine in the original post would blow the pants off the current diesels in towing comparisons.

You cannot make some people understand that this and/or the current 6.2 is a 'hot rod' engine not designed for towing, hence it is not available in 2500/3500 trucks