LT5 lower block question.

[Hog]

I was "discussing" with a guy who stated that the only thing that is similar between the LT5 and the 4.0/4.6 Northstar designs is that they are V8 engines made of aluminum.

While I would concede that there is zero parts interchange between the 2 engines(though I'm sure a bolt or 2 may interchange possibly) that there are some very similar design features between the 2 engines.


Now to my question, is this a picture of an LT5's lower block portion?(ASSuming a 1990-92-by its 2 bolt per main)


Here is the lower block portion of a Northstar V8


Northstar versions
4.6 liters equals-281 cid
4.4 liters equals 266cid (simply a 4.6 with a smaller bore for a stronger block for supercharger use
4.0 liters equals 244cid

LT5
5.7 liters equals 350 cid


L37 Northstar was rated at 300 sae net hp @ 6000rpm/295 lb/ft torque @ 4400rpm
=1.07 hp/cid
=1.05 lb/ft per cid

L47 Northstar "Aurora V8" 4.0l was rated at 250 sae net hp@ 5600rpm/260 l/ft torque @ 4400 rpm
=1.02 hp/cid
=1.07 lb/ft per cid

LT5 ZR-1 375hp @ 6000rpm/ 370 lb/ft torque @ 4800rpm
1.1 hp/cid
=1.06 lb/ft per cid

93-95 version 405hp @ 5800rpm/385 lb/ft @ 4800rpm
=1.16 hp/cid
=1.1 lb/ft per cid


Just for sh!ts and giggles, here is the Northstar 4.4l supercharged LC3 engine from 2006-09 RWD Cadillac STS-V's and the Corvette based XLR-V.
LC3 S/C 469 SAE "Certified Horsepower" @ 6400rpm/439 lb/ft torque @ 3900rpm
=1.8 hp/cid
=1.6 lb/ft per cid

As we can see, the power/torque densities are quite close for these N/A engines.
These premium high output DOHC, 32 valve, 4 flat tappet camshafts using chain drives, aluminum 2 piece block engines were advanced engines, esp considering the 80's technology both engines were designed with.