Clare,

Yep, they really stink. That's why, for the last 6 or 7 years, they've been
the basis of every IRL car. Not most. All. I'm sure that full girdle
surrounding the crank was so much weaker than the old style main bearing
caps.

Cracks between the cylinders? Show me the SB. Better yet, just give me the
number, I have all of them. You've obviously never seen how a Northstar
block is designed and built. They may crack somewhere, but I'd be amazed to
find one crack between the cylinders.

$8,000 CDN for a good used engine? Why not just shop EBay and take your
choice of low mileage complete cars for the same amount? How on earth did I
ever find my two engines (one with a 4T80E attached) with wiring and
computer for about $500 each? Maybe I should sell them to the Canadian
market.

As far as engine replacement if major repairs are needed goes, that's been a
CADILLAC policy for almost 20 years, long before the Northstar came on the
scene. It's a way to maintain high customer loyalty.

Obviously, someone you know hasn't had good luck with them. That happens.
Ask Unka Bob what kind of luck he has with GM products. That doesn't make
them a bad engine and they're far more advanced technologically than the
LS6. I like them so I play with them. You don't care for them, I'd suggest
you stay away from them.

Oh, and BTW, I'd rather work on 6 Caddy's than one damn Mercedes or BMW, and
don't even begin to talk parts price comparison with me. $700 for a damn
fuel pump in a Mercedes (like I just put in my brothers car)? Koni shocks
being $150 a pair cheaper for a BMW than the factory shocks. I think not.
And don't even begin to compare smoothness of the powertrain between one of
those cars and a Northstar because they simply don't compare.
Implementation my butt. I guess if you pay that much just to drive some
German or Japanese car it's easy to convince yourself just how superior it
is.

John Stricker

clare @ snyder.on .ca wrote in message
...
On Thu, 23 Oct 2003 00:26:48 -0500, "John Stricker"
wrote:

The Northstar of either the 4.6L or the 4.0 Liter are within 10 pounds in
weight to the LS6, ready to run. Many Northstars are still running with
no
visible wear on the cylinders after 150,000 miles. They had a problem
the
first three years of porous aluminum castings causing oil leaks that were
replaced by Cadillac with new engines. That problem hasn't been a factor
for quite a while. They had a service bulletin on the oil pump relief
valve
sticking as well which was addressed with a new design oil pump in '96.

I don't think you can make the mileage claim of the LS6 over the
Northstar
since they were never put in comparably weighted vehicles. I know that
the
guys that swap them into Fieros can routinely make well over 30 mpg on
the
highway, and the LS6 guys can't do that. But most of the LS6 guys are
using
manuals and not the 4T80E that the Northstar was designed to run in front
of.

Both the LS6 and the Northstar/Aurora can supposedly be driven with no
coolant but that's simply a factor of power limiting coming into play in
the
PCM. They won't allow them to make enough power to generate enough heat
to
cause a catastrophic failure. The other thing is they come standard with
an
external engine oil cooler that takes a lot of the coolant load off the
radiator. That doesn't change the complexity of the engine itself. They
use the same sensors and fuel management control. In fact, the LS6 fuel
pressure regulator is a bolt on that the Northstar guys use because there
are adjustable versions of it out there.

There is one major difference in the electronics of a Northstar over a
LS6.
The Northstar uses two crankshaft position sensors and a special toothed
segment on the crankshaft which allows the ECM to determine the precise
crank position within 180° of crankshaft rotation. That was incorporated
strictly to make the engine start quickly.

I don't know what you mean by "staying in one piece". The Cadillac is
good
to over 7000 rpm on a regular basis with stock rods, crank, and pistons.
The only time they get upgraded by the guys that push them is if they're
boosted over about 7 psi and making more than 525hp. They use the same
powdered metal construction rods the LS6 uses with full floating piston
pins. The engine I'm in the process of building uses turbo cams and
springs
from CHRFab that are good to 9,000 rpm. When I called around to some of
my
friends that were service managers in Cadillac dealerships to get some
information on rebuilding and weak spots, all of them said they really
didn't know much about it because they'd never had one apart.

John Stricker

Well, the caddy experts around here say the factory is "still trying
to get it right" and they can pretty well tell what failures to look
for by looking at the production date. One of the latest failures to
come to light is a fracture of the block, with no apparent cause.
Can't remember where, but IIRC between 2 cyls. Usually good to
150,000K, but some don't get half that far. They are Godawfull
expensive to replace, too. $8000 Canadian for a (hopefully) good used
engine????
Now to give credit where credit is due, they are a very technically
advanced engine, capable of significant power output, and very smooth
when running right. Possibly one of the best engine "designs" out
there - but the implementation is still not up to the standard of,
say, a Lexus.Or a Bimmer.Or a SBC II
My brother's shop services a large fleet of limos - and a year or so
ago they got rid of the last Caddy - had just Lincs and Mercs and a
Caprice. This was due to the expense of keeping the caddies on the
road. They have a couple (Chevy powered) Caddies in the fleet again
this year - and they've got their fingers crossed.

As for the dealers never having one apart, that is very likely true,
as when they have a problem they pull the engine out and drop a new
one in - the "defective" engine goes back to GM for an autopsy.
In my 25 years in the business, that only happened when the factory
had "concerns" with a given item.
In the early seventies with Toyota it was 1600cc cyl heads. For 6
months, every one that came off went back to Japan for analysis - and
they found out what the problem was, changed the type of sand they
used for the cores, and the problem went away. In a particular
production range, replacement level was close to 100% - and I was
replacing about 6 a day for weeks at a time.


clare @ snyder.on .ca wrote in message
.. .
On Wed, 22 Oct 2003 19:52:03 -0500, "John Stricker"
wrote:

Clare,

The Northstar system is functionally identical to the LS6 with the
exception
of a single crank sensor instead of 2 on the Cadillac.

John Stricker

clare @ snyder.on .ca wrote in message
.. .

The Northstar system is VERY daunting.


The LS6 is lighter, more powerful, and gives better mileage than a
Northstar. It also tends to stay in one peice, and running, much
longer than the Northstar. The LS6 has adaptive shut-down to allow it
to get home without coolant like the Northstar (supposedly) will? ? If
so, I was not aware of it. I thought it was ONLY the northstar and
Aurora engines that had those features.