Clare,

I appreciate your take on this, but some of what you think you know is just
plain wrong.

non-rebuildable engine. No undersize crank bearings are supplied. The

Not from GM. Federal Mogul offers them, though, and numerous places will
rebuild the cranks for about $200 US, exchange. There's a reason GM doesn't
recommend undersize bearings and that is the cranks are not grindable
without being heat-treated, which most won't do. What's economical for a
rebuilder to do is different than what's economical for GM to do. If it
costs them $200 in manufacturing costs to make a new crank, how can they
afford to offer a rebuilt one? (no, they don't sell them for $200). Every
component to rebuild the engine is available from GM. The cylinders can be
bored slightly (.010" or 3mm, IIRC, but I'd have to look that up). Mostly,
they don't get bored but they get honed oversized. BTW, give me one GM or
Chrysler engine that the FACTORY offers a REBUILT crankshaft for. I don't
know of any.

iron sleeves cannot be replaced OR rebored.

Just like 99% of the cast in place hardened sleeve designed alloy blocks
available now. Again, not from GM, but the aftermarket can fill the bill
quite nicely. Again, that's not true. They also almost never NEED to be
bored. The engine I'm building now had 120,000 miles on it, showed 0 taper
and 0 ridge. The factory hone marks were still visible. I had them cleaned
up and put the block through the washer, spent a day with the dial indicator
verifying straightness, and it's good to go. This is NOT unusual for a
Northstar block, this is the norm from what I've heard from the guys that
actually build these engines (one of them worked on the Cadillac LMP cars
that used the 4.0L version of the engine). You can also get forged pistons
from Arias and forged aluminum or steel rods from Eagle, if you like, at a
cost that's comparable to other engines. They're not really necessary,
though, unless you're running something over a 150 horse shot of nitrous or
more than 8-10 pounds of boost from a supercharger or Turbos. BTW, the
first year Northstar came from the factory with forged rods and crank, but
the following engines used powdered metal rods (like the LS6) and a vacuum
cast crank.

The early model Northstars had pourous castings, which caused oil leakage
THROUGH the
lower crankcase.
crankcase. The rear main seals were problematic and have been
retrofitted with a new press-in seal.

Not exactly. The girdles themselves were porous and when that was a
problem, the entire engine was replaced. Also, they have changed the
sealing procedures between the girdle and block as well as between the
girdle and pan because many of the "porous casting" complaints were actually
improperly sealed components from the factory. As you pointed out, though,
those were the early models before '95. That was almost a decade ago, in
model years. The rear seal changed designs because it was very difficult to
get them to seal during a service replacement, they didn't leak from new. A
new seal was designed that sealed better during a service installation.

The extended drain intervals
recommended by GM (don't change oil until the oil condition indicator
says so - 8-12,000 miles) has caused 2 serious problems with the
engines. Seized oil control rings, which cause serious oil burning,
and sticking oil pressure regulators (relief valves) which prevent the
engine from producing oil pressure. The fix for the stuck rings is
basically filling the cyls with carbon solvent, letting it sit for
several hours, and vacuuming it out through the plug holes. Then you
pray the cyl walls have not been scuffed by the stuck rings, or you
are in for an engine replacement.

This was addressed by recalibrating the PCM to shorten the engine oil life.
If the engines were used for primarily highway driving, there were few
problems. City stop and go driving, which the engineers thought they
compensated for with the software in the PCM, did cause the problems you're
talking about. BTW, the ONLY time you got that kind of mileage on the oil
indicator WAS if you were doing almost all highway driving. The computer
compensated life times based on engine temperature, engine speed, calendar
life, etc. I think there are 8 parameters involved and they simply got the
programming wrong. The change oil indicator could come on at anytime
between 2,500 miles and a maximum of 12,000 miles based on the parameters in
the software.

Another problem was that people use various quality grades of oil. Yes,
technically they all meet a minimum standard. The Northstar is NOT a
minimum standard engine, though, and, again, they got the programming wrong.

Your description of freeing the stuck oil rings is correct, although a bit
exaggerated, as far as it goes. (there was never enough top end cleaner
used to "fill the cylinders". It would be impossible to do in any case
given the layout of the Northstar intake.) What you failed to mention was
that if the service procedure didn't fix the problem, the customer got a new
engine. Virtually ALL of these failures happened while still under
warranty. Again, you're talking about the early engines. The computer has
since been reprogrammed with shorter oil service intervals.

You're also only partially right on the oil pump relief valve. Yes, the
service interval may have been a factor, but they also decided the relief
valve was not robust enough and came out with a replacement oil pump. That
pump, BTW, can be changed in the vehicle by removing the balancer and front
cover, then four bolts and the oil pump comes out from the front. Pan
removal is not required. The timing chains do have to come off, but if you
follow the factory service manual you can remove and return them for service
without re-timing the system.

There is also a procedure in the service bulletin to free the stuck relief
valve without removing any components, and it works about 1/2 the time. But
the oil pump really should be upgraded to the new style since it has other
improvements as well. That oil pump, BTW, costs about $85 at gmpartsdirect.
Would you like to compare oil pump prices to some of the other makes you
mentioned?

According to GM, the cyl heads are also "disposable" as the hard
powdered metal valve guides are reportedly non replaceable.

This is true, but also not unique to the Northstar. Most any of the makes
you already mentioned with DOHC direct actuation have the same limitations.

If repairing or replacing an engine, GM deems it MANDATORY to replace
the composite intake manifold, as it is virtually impossible to
effectively clean it and be sure there is no debris in it that will
get sucked in and damage the new or repaired engine.

That's not true. Replacement is only called for if the technician has
reason to believe foreign matter has entered the intake system. I just took
mine apart and put it back together, but it's the early design that uses a
magnesium housing with plastic, internal runners. These are not tuned as
well as the later versions, but superior for my application because the all
plastic manifolds have a large "soft plug" type design at the back that's
made to blow out in case of a backfire. (also to be able to remove it to
clean the manifold). These are problematic for engines that are going to be
used in a boosted application, though, as the boost may cause them to leak
or blow out, so the early ones are superior for my use.

Head gasket leaks are also not uncommon, and GM has revised the head
torque spec and sequence.

Leaking head gaskets are quite uncommon, but they have changed design and
composition to make them almost unheard of. The torque specifications were
changed because technicians were pulling the threads out of the aluminum
blocks. Head gaskets seem outrageously priced until you realize they come
only with a new set of head bolts since those bolts are torque to yield,
again, pretty much standard with aluminum block/head construction now. The
pulled thread problem is there in ANY aluminum engine, even Lycoming and
Continental. The Northstar, though, has a factory thread repair system
available for the inevitable occurrence.

The harmonic
balancers on the early engine had a tendancy to shift, causing rough
running.

Wrong. There is a new harmonic balancer and it addresses what I consider to
be one of the few design flaws of the engine. The harmonic balancer is held
onto the crankshaft with a key and bolt arrangement like most all other
engines. What's unusual is that the balancer pulls against a sleeve that is
the actual operator for the gearotor oil pump, which is NOT keyed to the
crankshaft in any way. The crank timing sprocket is between the two. You
torque the bolt down, pulling the balancer in, clamping the sprocket and the
sleeve with clamp pressure alone. What happened with the old style balancer
is that sometimes it would not hold the proper clamp force and would allow
the sleeve to slip. A new design balancer was released, with a new bolt and
torque spec to address the problem. The balancer cost me about $48, IIRC.

It's an interference engine too - and with overhead cams - I'm not a
great fan of LONG timing chains after the 2.6 Mitso****ty fiasco.

Nearly all high performance DOHC engines are interference engines. It's
hard not to have one with a 4 valve, hemi head, running 10:1 compression and
have reasonable valve lifts. The math just doesn't work any other way. Now
tell me how many Northstars you can recall, or have your friends recall,
that EVER had a failed timing chain that caused a problem? I won't hold my
breath while you're looking, because it has a very simple and robust system
that simply doesn't break.

The starter, buried in the bowels of the engine, commonly succums to
the heat, requiring removal of the entire intake system.

Buried? It's in the vee below the intake. It takes a competent mechanic
less than 30 minutes to remove a Northstar intake. On top of that, the
starter is surrounded by the engine which runs at a fairly sedate 200°F as
opposed to being on the side of a block within inches of 1300°F exhaust
pipes. They're also protected from road debris, salt, and water. The
starter location was a conscious decision by GM to avoid service problems to
begin with. I can change a Northstar starter faster than I can change one
on a small block Chevy, in most cases. Again, how many Northstars have you
heard of that have had to have the starter replaced?

May as well go to the casino - it's a crapshoot - enough of a risk
buying from wreckers who give a warranty on the engine (1 year for
personal use, 90 days commercial)

And this differs from other engines just how, again??

and there are NO rebuilt Northstars
available in Canada. The major rebuilders won't touch them.

Maybe not from GM, but there are rebuilders here that offer them. If
they're available here, they're available in Canada as imports.

Even a blind pig will find the occaisional acorn.

Should I comment on that, Clare, or are you relating your own personal
experiences?

Over the years I have not been a great GM fan - nothing against them -
but I've had Mopars, Toyotas, AMCs, other assorted oddballs, and a
couple of Fords. I had a 28 Chevy and a 35 Chevy, a '57 Chevy, and a
'67 Nova.

Not been a great fan of GM's, but you have nothing against them. At the
same time you're pointing out as weaknesses of the Northstar things that are
now industry common items, like having to replace the head bolts every time
they're torqued (you forgot to mention the rod bolts in the Northstar are
also torque to yield), interference design of the valves, etc.

I'm of the KISS persuasion. If I'm not racing, 2 valves are as good
as 4, one cam as good as 4.

That's why you're not able to get 65-70hp per liter, unless you're racing.
The Northstar does it in a car grandma can drive.

For the price of a Caddy I can drive some pretty nice Japanese
machinery.

Different strokes for different folks. I personally drive a Riviera. To
me, though, "pretty nice Japanese machinery" is an oxymoron. Especially
when you have to go to the parts counter and pay the piper.

How about several hundred dollars for a replacement fuel rail for a
SEFI 3800 GM? A lot of other insane prices too - like the automatic
level control compressor for the TransSport? Or the front sway bar? Or
the MAF sensor? I get sticker shock every time I need a part for the
Pontiac - I thought the Chryco parts were expensive. Every part I have
required for both of them has been more expensive than for my old RWD
Ford, or any of my Toyotas. They Toys all went over 300,00km without
opening the engine. Or the transmission.

Nest time, go to http://www.gmpartsdirect.com and order your parts. They
ship to Canada.

Fuel rail is $284.09 + frt (although I don't know why you wouldn't find one
of THOSE at a salvage yard). They didn't show the sway bar, but any parts
you can't find there you can email them for a quote. The ALC compressor is
$262.18 + frt. The MAF is $102.79 + frt. I realize you're dealing in
Canadian $$, but that's not as big a difference as it was 6 months ago
(unfortunately for us). I don't know how those prices compare to other
makes, but I know a Ford MAF is more than that for their light trucks.

Some parts cost a lot, others don't. Specialty parts from GM often cost
unless they're the subject of a service bulletin, then they're pretty
reasonable as I've shown above. OTOH, how about pricing things like routine
maintenance items for the imports and the GM/Ford/Chryslers? That's where
they hang it in your butt, and if you've driven them you know it just as
well as I do.

300,000 km? That's about 187,000 miles. I'm not impressed. My GM vehicles
are just getting broken in at 150,000. My '83 service truck has over
500,000 miles (800,000 km) on it and we just had to put a rebuilt engine in
it last year at 480,000. It still ran, but was lacking some power and
starting harder than it used to. This is a 6.2L diesel that many deride as
being powerless and unreliable.

The Northstar is not a perfect engine. I've never found a perfect engine.
It is the most technologically advanced engine available at the moment from
a US manufacturer of US design. I can point out at least a half a dozen
potential trouble spots on the engine that you didn't touch on, but that
isn't the point.

I've come to the conclusion that people generally get what they expect out
of a vehicle or engine. Sometimes not, but most times. Take my old LeSabre
for instance. We had it for several years. The wife drove it almost daily
putting over 150K miles on it. We had to put a transmission in it at around
120K. Other than routine maintenance and a fuel pump, that was it.

When we got a new car we sold the Buick to Unka Bob. Now Bob isn't shy
about telling you that he and GM have never gotten along. Never. But both
he and I thought that the Buck (not a mis-spell, the "i" fell off at some
point in time and it was affectionately known as the Buck from that day
forward) would be fine for him, based on it's past history with me. A
friend and I drove it to KC to take it to him and pick up a POS Cherokee to
fly home for an annual on a ferry permit. We went to Unks house and he took
us to the airport.

He literally did not make it the 20 miles home before the a/c compressor
flew to hell. From that point on, it has been one thing after another that
has failed on the car. I don't think he's been able to drive it 500 miles.
I even offered to buy it back. We even talked about if I bought it back,
we'd get it running long enough to take it to the auto auction, sell it, and
use the money to get drunk for as long as the money held out.

But Bob's on a quest now. He's going to find out what's wrong with it if
it's the last thing he does. Then he'll sell it. I think it's a matter at
this point of not letting the rotten SOB beat him. There's certainly no
financial reason for him to keep after it, but he does.

You might have noticed he's a little stubborn that way.

You seem to think the Northstar is a greatly inferior engine and I think
you're mistaken. But you're certainly entitled to your wrong opinion. 8-)
It is NOT, and I repeat NOT, a suitable engine for aircraft conversion,
IMHO, so I think I'll just let this thread die now without further comment.

John Stricker