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.

[Paul Workman]

Nope.

This is the lower of the two-bolt LT5:

[WVZR-1]

Originally Posted by 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)

Yes I believe you're correct with your assumption. The image looks like it may have been from a post by JP back in '07 here's that post:

http://zr1.net/forum/showpost.php?p=24393&postcount=1

Paul - your image is with it installed and Hog's is the internal aspect of the crank-case half facing up.

[spork2367]

Originally Posted by Paul Workman

Nope.

This is the lower of the two-bolt LT5:

You realize it the same thing from the opposite side right?

[Schrade]

If LT5 can handle 1k HP, or near that, then can a stock mill get all the protection it needs with lightweight oil that has the ZDDP additives? And more power output, with less fluid resistance???

[spork2367]

Originally Posted by Schrade

If LT5 can handle 1k HP, or near that, then can a stock mill get all the protection it needs with lightweight oil that has the ZDDP additives? And more power output, with less fluid resistance???

I don't think such a direct correlation between HP and oil weight can be made. Bearing clearances, oil returns, pump pressure and volume, rpm's, materials, operating temp, etc. are what determine oil weight, whether you have 100 HP or 1000.

That being said, I run http://www.penngrade1.com/. It has some of the highest zinc and phosphorus content out there. It's not recommended for use in vehicles new than 2005 due to some problem with more modern catalytic converters. The pulling tractor guys around here swear by it.

[RyanChappel]

Another potential to throw on the pile....

What's a 'Waxer' trying to move up in the world to do....

Oh! The Humanity....

[spork2367]

Originally Posted by RyanChappel

Another potential to throw on the pile....

What's a 'Waxer' trying to move up in the world to do....

Oh! The Humanity....

You lost me.

[RyanChappel]

Sorry to lose you..not intentional...

There has been a thread around for a long time regarding the different opinions of the engine oil owners run....Mobil1, Mobil1HM, 5W,10W,Amsoil,CastrolHM...combinatons......etc.

"Waxer" has been used in a pejorative sense to describe some of us who do not have anywhere near the skills some of the posters on this site have, but are for the most part limited to 'Washing and Waxing' (Waxers).

As a 'Waxer', I have been attempting some small maintenance tasks, and am planning an oil change soon....and reading the threads on different oils and filters available...when I saw your Penn/Grade link, it was the first time I had seen this one...hence the post.

Good luck with your LT5..Thanks for posting and the photos..

[spork2367]

Originally Posted by RyanChappel

Sorry to lose you..not intentional...

There has been a thread around for a long time regarding the different opinions of the engine oil owners run....Mobil1, Mobil1HM, 5W,10W,Amsoil,CastrolHM...combinatons......etc.

"Waxer" has been used in a pejorative sense to describe some of us who do not have anywhere near the skills some of the posters on this site have, but are for the most part limited to 'Washing and Waxing' (Waxers).

As a 'Waxer', I have been attempting some small maintenance tasks, and am planning an oil change soon....and reading the threads on different oils and filters available...when I saw your Penn/Grade link, it was the first time I had seen this one...hence the post.

Good luck with your LT5..Thanks for posting and the photos..

lol. Got it. For some tech...

Amsoil zinc and phosphorus content vs Brad Penn.

Amsoil:

Phosphorus: 1265 ppm

Zinc: 1378 ppm

Brad Penn:

Phosphorus: 1332 ppm

Zinc: 1565 ppm