: Northstar vs LT1



BeelzeBob
07-08-03, 07:48 PM
Which do you prefer? And why? Which has more horsepower? Which has more torque? Which has the better powerband? Discuss... In case you didn't know, the LT1 was used on the Fleetwood from 94-96...

scourge
07-08-03, 08:15 PM
I'd take a NorthStar. It can just as much hit 1000hp or be tuned for more reasonable applications. I don't know about torque, but the Caddy hot rodders are quite happy with the engine. And, IIRC, isn't the NorthStar a real Caddy engine. Wasn't it developed in-house rather than being brought over from Chevy?

BeelzeBob
07-08-03, 08:20 PM
I personally don't care where the engine came from. But yes, the Northstar is made for Cadillac only where the LT1 is a Chevy engine.. I think the LT1 probably has about the same potential as the Northstar but I'll bet it's a lot less expensive to maintain.. I've heard the Northstar could cost $8000.00 to replace...

banstyle
07-08-03, 08:33 PM
I know in terms of electronics, there's a SHITLOAD more out there for the LT1 than the NorthStar, as well as internal capability. The OBDII package I'm getting for my car-puter can let you PROGRAM the chip in the LT1 with your own shift patterns, timing, etc. Simply can't do that with the N*.

In terms of motor, I'd take a N* over the LT1 any day. scourge has it right... there are rodders out there that do some amazing things to the engine. Plus, I'm into the design aspect as well, and the N* is just more interesting to me... :)

elwesso
07-08-03, 10:03 PM
It all depends on what you want.....

Personally, I would take either, but IMO the major differences are

1. The LT1 has more of a performance aftermarket, but the northstar is quite a bit more powerful from the get-go.....
2. The Northstar is FWD, and the LT1 is RWD.... Although the northstar could be RWD easy enough
3. The LT1 is quite a bit more reliable, it is a much simpler design, and not so technologically advanced......


As far as horsepower, I cant remember the LT1 right off hand, something like 260 something........

But take in mind, the LT1 has its torque much lower in the powerband..... in a more useful area....

You can do some pretty mean burnouts in a FW with LT1..... It looks pretty weird for a 18ft vehicle driving sideways down the road!!!!

BeelzeBob
07-09-03, 07:14 AM
The LT1 that's used in the Fleetwood is a downgraded version of the LT1. So let's just compare the Northstar to the LT1 without the downgrade. 300 horsepower..

So which engine is more powerful?

I'm not too sure about the low-end torque on the LT1. The LT1 (92-96 Corvette) and the L98 (85-91 Corvette) had the same 0-60 numbers. BUT - the 1/4 mile was better for the LT1 powered Vettes.

L98 Vettes were faster off the line and won most stop-light races. In fact, the L98 is quicker off the line than the current LS1 powered Vettes.. So I don't know how powerful the LT1 is down low. But I know it's powerful up high...

Now the Northstar is very powerful up high as well...

HotRodSaint
07-09-03, 08:23 AM
But yes, the Northstar is made for Cadillac only...

Wasn't the N* the same as the Oldsmobile Aurora engine, except that the Olds had different heads?

McMoo
07-10-03, 02:19 PM
For modding LT1 no doubt. It has more potential, and will cost much less to mod than the northstar. Stock they have about the same power, Lt1 vette is 300hp 335 torque, northstar is 300hp 295 torque. Also the lt1 has a lower powerband, peak torque is around 3000 rpms. There are lt1's pushing over 1000 hp, and stock bottom end ones with over 500. I'm not sure the northstar could take that. Not to mention the lt1 is much easier to work on, pushrod vs. dohc. The northstar is much smoother and better for a luxury car no doubt but the pure power of the lt1 cant be beat.

elwesso
07-10-03, 09:49 PM
Ill take a good ol RWD pushrod any day!!

I just got back from the lakes, and all the marine engines are chevy, ford, and chrysler small blocks...... It is really cool hearing that roar at 4000 RPMs with straight exhaust........

Katshot
07-10-03, 09:50 PM
I'd agree with McMoo for the most part. The LT1 is a more reliable, more workable engine. From the factory, the LT1 was more powerful than the Northstar in all applications except the B & D body cars. And in those applications, the powerband is much broader which means more useable power across the rev range.
BTW, The Northstar was originally an Oldsmobile engine design. Olds ran out of developement money and Cadillac, (needing an engine of their own at the time) picked up the design ball and kept throwing money at it until they got it to work. It's a fairly good design but has been hampered by typical GM bean-counter cost-cutting efforts, which has produced a very similar situation to the HT4100.
Yes, the Northstar is more complicated in design and build than the LT1. Yes, it has the ability to be one of the greatest engines in the world. But unfortunately, the Northstar has been saddled with limited applications (only FWD luxo-boats for the first several years of it's production) and a rather short-sighted marketing effort (after nearly a DECADE, the engine is still unable to handle a serious performance car role).

MMNineInchNails
07-10-03, 09:54 PM
Ill take a good ol RWD pushrod any day!!

I just got back from the lakes, and all the marine engines are chevy, ford, and chrysler small blocks...... It is really cool hearing that roar at 4000 RPMs with straight exhaust........

Yep, my dad has a small block chevy 350 in his Malibu. His friends call it it the cadillac of boats because it rides so smooth across the water.

elwesso
07-10-03, 09:54 PM
What I dont understand is why they run those engines so hot..... i mean, my engine is supposed to run at 176*F, and the northstar runs about 200-220........ What gives??

elwesso
07-10-03, 09:55 PM
My grandpa owns a 68 chris craft commander 23 with the origional engine..... 327 chevy, boy that thing can ROAR!!

Katshot
07-12-03, 09:49 PM
What I dont understand is why they run those engines so hot..... i mean, my engine is supposed to run at 176*F, and the northstar runs about 200-220........ What gives??

The answer is emmissions Wes. That, and it keeps down carbon formation.

elwesso
07-12-03, 10:22 PM
Alas, I have been enlightened :worship:

Then how do other companies run their cars cooler and still pass emissions??

BeelzeBob
07-14-03, 08:54 AM
Good explanation - and good question...

One more question.. How much more smooth is the Northstar than the LT1? Is it really a noticable difference when driving?

Katshot
07-14-03, 09:18 AM
Good explanation - and good question...

One more question.. How much more smooth is the Northstar than the LT1? Is it really a noticable difference when driving?

Engine temps on most if not all modern engines is usually around the 200-220 degrees F regardless of what the gauge says.

The engine "smoothness" as you describe it is very good on both engines. The vibrations felt in the passenger compartment are more a result of engine mounts and body/chassis tuning and not so much the engine. Both cars provide extremely good drivetrain isolation.

elwesso
07-14-03, 03:24 PM
What makes the corvette powered LT1 more powerful than the FW LT1???

Katshot
07-14-03, 07:34 PM
What makes the corvette powered LT1 more powerful than the FW LT1???

Main differences are cam and heads. PCM programming and less restrictive intake and exhaust also help quite a bit.

Devil_concours
07-15-03, 07:58 AM
I've always thought north* engine had a quite bit of big aftermarket turbos and superchargers allowing it to produce over 700hp.
Anyways, unless it was a ls1/ls6 I will still take the north* over lt1.
because
1. Most north* powered cadillacs are fwd and if it had much low end torque as lt1 then it might not get good traction
2. I actually love the way north* engine revs. Very fast and nicely providing the driver with silky smooth sound and feel
3. I prolly won't do much with either engine because most cadillacs do not have enough room under the hood to install any forced induction system.

Katshot
07-15-03, 08:28 AM
I've always thought north* engine had a quite bit of big aftermarket turbos and superchargers allowing it to produce over 700hp.
Anyways, unless it was a ls1/ls6 I will still take the north* over lt1.
because
1. Most north* powered cadillacs are fwd and if it had much low end torque as lt1 then it might not get good traction
2. I actually love the way north* engine revs. Very fast and nicely providing the driver with silky smooth sound and feel
3. I prolly won't do much with either engine because most cadillacs do not have enough room under the hood to install any forced induction system.


There's actually very little aftermarket stuff geared toward the Northstar. The reasons are as follows:

1. Majority of Northstar owners are NOT liable to favor performance upgrades to their cars.
2. In factory trim, the Northstar engine is NOT by any means ready for any "bolt-on" performance upgrades, especially forced induction.
3. Cost of the Northstar engine is rather high and for that reason it does not easily lend itself to the DIY'r.
4. The engine compartment of all Northstar equipped cars is too cramped and hot for doing most performance upgrades that would include addition of componentry.

This is not to say that it CAN'T be done, there are a few people that have in fact, modified the Northstar engine for applications both in and out of Cadillac cars. The point is that the engine and the platforms it is found in, do not lend themselves to such modifications.

SoundAdvantage
08-05-03, 03:59 AM
Which do you prefer? Any why? Which has more horsepower? Which has more torque? Which has the better powerband? Discuss... In case you didn't know, the LT1 was used on the Fleetwood from 94-96...

I prefer a Chevy Cast Iron Block and Cast Iron heads over the all aluminum Northstar engine simply because of longevity, and i do love Chevy engines! :spin: but im "old school" when it comes to V8 Powerplants. :sneaky:

chrisngrod
08-05-03, 11:54 AM
Most of the upgrades for the N* mentioned have been for dune buggies etc... For these even there are tons of internal modifications done for even fairly low increases. I do hope to see the supercharger out soon before I disown the car and make a twin turbo SC300.

Devil_concours
08-05-03, 07:44 PM
Most of the upgrades for the N* mentioned have been for dune buggies etc... For these even there are tons of internal modifications done for even fairly low increases. I do hope to see the supercharger out soon before I disown the car and make a twin turbo SC300.

well we weren't comparing cars just engines.

chrisngrod
08-05-03, 10:05 PM
Well I like to talk about stuff I can actually use :-).

Devil_concours
08-05-03, 10:13 PM
Well I like to talk about stuff I can actually use :-).


well if you really want to you CAN use everything above in your car. :D

chrisngrod
08-05-03, 10:23 PM
be reasonable now =)

HotRodSaint
08-07-03, 08:51 PM
The September issue of Street Rodder has the first of two article about hot rodding a northstar.

the Sandman
08-07-03, 09:40 PM
What I dont understand is why they run those engines so hot..... i mean, my engine is supposed to run at 176*F, and the northstar runs about 200-220........ What gives??
Engine temps on most if not all modern engines is usually around the 200-220 degrees F regardless of what the gauge says. I think we're talking about two different things here. The ideal oil temp for most if not all modern automobile engines, street and race, is around 220 degrees. This is not the same as the coolant temperature. On most cars today, the thermostat opens around 195 degrees, and that's where the coolant temperature should usually remain assuming the cooling system is in good operating condition and not overly stressed (very high ambient temps, A/C, towing, sitting in traffic, climbing significant grades). In past years, the 'stat opened earlier, like 180 degrees, but this did lead to higher emmisions. Lowering the coolant temps, and thereby lowering the oil temps, can lead to slightly increased horsepower when accompanied by appropriate timing changes, but also leads to sludging of the oil due to insufficient boiling off of water contaminating the oil. The Northstar cars run higher coolant temperatures due to packaging problems underhood - the large transverse engine generates a good deal of heat and there is simply not enough airflow through the radiator and engine compartment to efficiently get the coolant temps down. So instead, they designed the system to work with higher coolant (and underhood) temps - thats why, for instance, they use the watercooled alternator - its so hot under the hood that the alternator would not be able to maintain adequate output and would fail prematurely. However, the oil temperature inside the engine is still in the 220 degree ballpark.

There really is no such thing as "the engine temperature". The engine has areas which are hotter (combustion chamber, heads) and areas which are cooler - no one temperature can describe it. Engine oil temperature is what is usually measured although it is possible to put one or more thermocouples in the motor and read actual engine temperatures at the probe.
How much more smooth is the Northstar than the LT1? Is it really a noticable difference when driving?I'm not sure about the LT1, but the LS6 in the CTS-V (from the Z06 of course) has been described in the two magazines I've seen so far that have actually driven it as being very smooth - much smoother than expected considering the aggressive cam profile - and completely appropriate for a hot rod Cadillac.

Katshot
08-07-03, 10:22 PM
Not bad post but......you KNEW there'd be a BUT right. I'm DIEING to know why you brought up oil temps. You ARE close on the ideal oil temp though. I've found that 200 degrees is a good temp but different engines will have far different oil temp characteristics, some as high as 270-280. But I think if you checked, you find that few modern V8s break 200 degrees. Engine coolant temps on the Northstar have nothing to do with "packaging". Under-hood temps yes, coolant temps, NO. Coolant temps are kept high in modern engines for several reasons including improved emissions, gas mileage, and reduced carbon deposits within the engine.
Water cooling the alternator was a cute idea but DID NOT actually work and as far as I know was discontinued across the boards.
You're right about the coolant temp NOT being consistent throughout the engine but it really doesn't matter since the engine performance parameters and subsiquent PCM programming are NOT developed using such a crude method anyway.
Oh, and the comment about how the coolant should remain around the thermostat opening temp is not even close. As a rule of thumb, most engines tend to operate quite a few degrees above the thermostat opening temp because the fan programming controls the average coolant temp more than the thermostat. The thermostat's job is more to aid in a quick warm up period than to maintain the engine's coolant temp. Matter of fact, the Northstar tends to operate right around 210-215 as I recall.
And finally, who cares about the LS6? The guy asked about the LT1 so what would make you try to relate the LS6 to the LT1? Just because they are both 5.7 liter Chevy V8s? The L99 would at least be the same engine family but still would not be comparable to the LT1.
In answer to the question though, the LT1 when tuned properly will provide a "glass-smooth idle" that Northstar owners could only DREAM of.

Brett
08-07-03, 10:45 PM
In answer to the question though, the LT1 when tuned properly will provide a "glass-smooth idle" that Northstar owners could only DREAM of.


I dont know much about this other stuff, but i do know it would be pretty hard for the idle on my northstar to be much smoother, its pretty hard to tell if the engine is on. People with base devilles with no tach, probably grind their starters all the time

elwesso
08-07-03, 11:03 PM
Ive done it on mine!!! When the AC and radio is off, I can hardly hear the engine, if at all.......

Blackout
08-07-03, 11:05 PM
Ive done it on mine!!! When the AC and radio is off, I can hardly hear the engine, if at all.......
gotta love sound proofing materials! :thumbsup:

the Sandman
08-07-03, 11:34 PM
Not bad post but......you KNEW there'd be a BUT right. I'm DIEING to know why you brought up oil temps. You ARE close on the ideal oil temp though. I've found that 200 degrees is a good temp but different engines will have far different oil temp characteristics, some as high as 270-280. But I think if you checked, you find that few modern V8s break 200 degrees. Engine coolant temps on the Northstar have nothing to do with "packaging". Under-hood temps yes, coolant temps, NO. Coolant temps are kept high in modern engines for several reasons including improved emissions, gas mileage, and reduced carbon deposits within the engine.
Water cooling the alternator was a cute idea but DID NOT actually work and as far as I know was discontinued across the boards.
You're right about the coolant temp NOT being consistent throughout the engine but it really doesn't matter since the engine performance parameters and subsiquent PCM programming are NOT developed using such a crude method anyway.
Oh, and the comment about how the coolant should remain around the thermostat opening temp is not even close. As a rule of thumb, most engines tend to operate quite a few degrees above the thermostat opening temp because the fan programming controls the average coolant temp more than the thermostat. The thermostat's job is more to aid in a quick warm up period than to maintain the engine's coolant temp. Matter of fact, the Northstar tends to operate right around 210-215 as I recall.
And finally, who cares about the LS6? The guy asked about the LT1 so what would make you try to relate the LS6 to the LT1? Just because they are both 5.7 liter Chevy V8s? The L99 would at least be the same engine family but still would not be comparable to the LT1.
In answer to the question though, the LT1 when tuned properly will provide a "glass-smooth idle" that Northstar owners could only DREAM of.I'll defer to you on most of this. I was going a bit beyond actual knowledge and speculating...here and there. I am pretty sure my alternater is water cooled, though. And I think the 270-280 degree oil temps are a bit high if we're talking steady state cruising. Under heavy load, yes, it will go up. And I'm not convinced it's the coolant temps that affect mileage and emisisons, at least not in conventional cooling circuits...reverse flow, maybe, since the heads get priority cooling. I think the oil temps are more important. The oil temps are related to the amount of heat the cooling system is able to remove per unit time, not the actual temperature of the coolant itself.

I agree the LS6 comment was offtopic to this discussion. I wasn't saying that the smoothness of the LS6 was a reflection of the LT1's smoothness. It just seemed like a good opportunity to note the apparant success of the CTS-V.

And I agree that the Northstar's idle could be smoother - they hide the roughness well with superduty engine mounts and sound insulation, but if you watch the tach you can see it, and if you pay close attention at idle you can feel it even through the plush seats. In fact, many of the improvements to the Northstar leading to the new Gen II address NVH issues.

SoundAdvantage
08-08-03, 01:48 AM
Come on with it Kevin :worship: Tell us what your Honest opinion about the Northstar IS > I know enough to stay away from one but You know ALOT more about BOTH of these engines than most unsuspecting owners. Why are the Northstars Blowing Head gaskets so often? Why do you have to add "Coolant stop leak" to the cooling system on them? WHY do the Northstar engines "BURN OIL" ? I was in the market for a 94/97 STS earlier this year untill my mechanic talked me out of it > I DON'T take my cars to the Dealer > EVER, but if i bought a Caddy with a N* my mechanic told me he Would NOT be able to work on it! and I would be stuck taking it to the Dealer to pay $High Maintanence$ costs.

Katshot
08-08-03, 09:49 AM
I would agree that 270-280 degrees would be on the high side during a "steady state" cruise (unless it was at a very high-speed), but I wasn't aware we were talking about temps at those operating parameters.
The engine temp IS maintained through the coolant via electronically controlled fans and ram-air effect through the radiator at higher road speeds. So I don't think it's too much of a stretch to understand that coolant temp has a direct effect on cylinder head temps, which in turn has a controlling effect on combustion chamber temps, which has a major effect on both gas mileage and emissions.
Temps were raised back in the late 80's in an effort to control HC (Hydrocarbons) and CO (Carbon Monoxide) but introduced an unforseen problem. NOx was created by the very thing that helped to oxidize the other pollutants, very high combustion temps (over 2500 degrees). That's when more careful EGR control was needed. EGR by it's very design reduces the combustion temps to help prevent detonation and in this case, it helps keep the temps just below the threshold of NOx production.
Beyond that, the higher temps help to limit carbon deposits on the combustion chamber and valves. These deposits can (and do) mess up the carefully designed flow characteristics of the heads and thereby increase emissions and decrease both power and fuel mileage.
Oh, BTW, as far as I've been able to tell, the water-cooled alternators were only used in '98-'99 Sevilles.

And to answer Mikes questions:
Northstars blow head gaskets because they suck.
You have to use the coolant additive in Cadillac Aluminum engines because they suck. And Northstars burn oil because they suck.

Ok...that was just to be funny.

Northstar engines blow head gaskets because:
1. Some engines were manufactured with improper size head bolts.
2. Some engines were manufactured with improperly machined headbolt holes.
3. Some engines were manufactured with improperly torqued heads.
4. Some engines were manufactured with defective head gaskets.
Take your pick.
The coolant tabs are to help maintain the integrity of the cooling system, lubricate the pump, and help seal minor leaks. Without them, cylinder liner seals breakdown and leak allowing oil and water to mix (that's a bad thing), and eventually causing engine failure.
Why do Northstar engines burn oil? Damn good question. Not all of them do. I've read the reports about aggressive cylinder cross-hatching and personally don't believe it. If that were the case, ALL the engines would use oil at virtually the same rate. This is NOT the case though. on this question, I'm likely to rely on my ORIGINAL comment above, they SUCK.

Night Wolf
08-08-03, 11:18 AM
Ive done it on mine!!! When the AC and radio is off, I can hardly hear the engine, if at all.......

not with my car, if everything is off, inside with the windows up, you can hear it..... but ore fell it...... I guess the 4.9 just has a rough idel, and sometimes you can feel it through the car....dosn't bother me, as soon as the rpm come up just a tad it smooths out alot, then is more quite (actualy has a certain whine to it) then when you race it, it just gets downright aggressive :D

Night Wolf
08-08-03, 11:21 AM
Kevin...... maybe you can help me out with a question:

I once heard that the metals used to make the NorthStar between the block and heads or something like that, were not comon metals, they repel each other, and after years of use (5-8 or something like that) they start seperating or something and it ruins the engine....... ever hear anything about that? How come I don't hear about it anymore?


You have to use the coolant additive in Cadillac Aluminum engines because they suck.

my 4.9 has an aluminum block with cast iron heads......does that mean it sucks?

Katshot
08-08-03, 01:00 PM
Kevin...... maybe you can help me out with a question:

I once heard that the metals used to make the NorthStar between the block and heads or something like that, were not comon metals, they repel each other, and after years of use (5-8 or something like that) they start seperating or something and it ruins the engine....... ever hear anything about that? How come I don't hear about it anymore?



my 4.9 has an aluminum block with cast iron heads......does that mean it sucks?

Panther,
To be honest, I have read about this in another thread here (maybe one of yours), but I have never heard it before. Believe me, that means nothing because I certainly don't claim to know EVERYTHING about that engine. It's possible I guess. You use the word "repel" but I'm assuming you're meaning they are "dissimilar" metals.
This can, and does cause problems with many machines that are made up of dissimilar metals. Matter of fact, the corrosion that sets up because of it is sometimes called "dissimilar metal corrosion". Anytime you have two dissimilar metals together in the presence of a conductive liquid (like engine coolant), you basically have a battery. This causes a process called "electrolysis" or "Galvanic Corrosion" and there is actually a voltage generated as the two metals react on each other. The process can actually fuse the two metals together and will eventually deteriorate the material which becomes the "anode" and slow the corrosion rate of the material that becomes the "cathode" if not actively kept in check by the use of certain lubricants, coatings, and sealers. This may give you an idea of how complicated the art of designing and building engines has become. Bet you never thought your engine was also a battery huh?

the Sandman
08-08-03, 01:15 PM
The recommended interval to change the coolant on the current Northstar cars is what, 100,000 miles? My dealer recommends a flush every 15,000 miles "due to our southern climate". Anyway, I'm following the dealer's recommendation in the hope that it will ward off evil spirits and keep the engine hummin'. Longevity issues aside, the Northstar is a fun engine as long as it's performing to spec.

AirJigga25
08-08-03, 01:26 PM
(only FWD luxo-boats for the first several years of it's production) and a rather short-sighted marketing effort (after nearly a DECADE, the engine is still unable to handle a serious performance car role).

might have to agree on this one... :bonkers:

Brett
08-08-03, 01:34 PM
To be fair, its not like every N* just grenades at 70k miles. Kat I'm sure you've seen alot of high mileage N*'s in your time. Maybe the Second Gen on the XLR and SRX will be better, but since they are higher tech, probably not

the Sandman
08-08-03, 01:38 PM
...only FWD luxo-boats for the first several years of it's production and a rather short-sighted marketing effort after nearly a DECADE, the engine is still unable to handle a serious performance car role.Might have to agree on this one...Early reports suggest the Gen II Northstar to be a serious player in the XLR and SRX. Of course I'm the "glass half full" type...

Katshot
08-08-03, 02:36 PM
Sandman,
Although I would disagree with 15K coolant flushs, you certainly won't HURT anything by doing it that often. I think if you keep with the "OEM recommended" interval, you'll always be safe as far as your warranty and if you want to be EXTRA cautious, I would think you might want to adopt the "severe service" maintenance schedule. Then you should DEFINATELY be safe. The obvious question would have to be, "what's the severe duty interval"? That, I don't know. Anybody with an owner's manual here?

the Sandman
08-08-03, 02:50 PM
Sandman,
Although I would disagree with 15K coolant flushs, you certainly won't HURT anything by doing it that often. I think if you keep with the "OEM recommended" interval, you'll always be safe as far as your warranty and if you want to be EXTRA cautious, I would think you might want to adopt the "severe service" maintenance schedule. Then you should DEFINITELY be safe. The obvious question would have to be, "what's the severe duty interval"? That, I don't know. Anybody with an owner's manual here?Yeah, that would be good to know. So, you think the dealer is just trying to get more money by performing unnecessary services - I wondered about that myself. It's not just something they told me, they have a whole fancy booklet they printed up with what they recommend at each particular mileage along with a "special" price.

Katshot
08-08-03, 02:56 PM
To be fair, its not like every N* just grenades at 70k miles. Kat I'm sure you've seen alot of high mileage N*'s in your time. Maybe the Second Gen on the XLR and SRX will be better, but since they are higher tech, probably not

No, you're right they ALL don't, some go WAY SOONER! ;)

To be honest Brett, the Northstar was the ONLY engine from Cadillac that I could NEVER depend on certain things happening at certain points during its life. Failures tended to be sporadic as hell and definately happened in groups depending on manufacture dates. This, definately made me feel that the production procedures were constantly in a state of flux. We had different failures in different groups of engines from day one. And I know I mentioned it here before but just in case anybody missed it, there are Northstar failures under investigation right now that you guys have not even HEARD of yet. One I mentioned before was a block cracking problem that is being seen in an aweful lot of engines and there's supposedly NO EXPLANATION for it yet. Yes these are in higher mileage engines (approx. 150K miles) but there are a lot of Caddys out there with that kind of miles on them too.
I will continue to say that even though the Northstar is an awesome engine when it's running properly, I DO NOT trust it's long-term reliability.
And bearing that in mind, I have to point out that Cadillac has a very poor track record with its aluminum engines and it is probably the one largest reason for their having such a poor reputation in the marketplace.
That, and their going to FWD has been a HUGE weight around their neck.
Hopefully, their moving back to RWD signals their desire to get serious in their supposed target market. Now all they have to do is put a better engine in their cars.

the Sandman
08-08-03, 03:19 PM
...as far as I've been able to tell, the water-cooled alternators were only used in '98-'99 Sevilles.So far, I've been able to find online documentation (at media.gm.com) of water cooled alternators on Sevilles up to 2001. The alternator on my '02 has water lines - I'm gonna say it is water cooled as well.

Katshot
08-08-03, 03:39 PM
Could be, I just called my freind at the dealer and had him look it up. He told me the '98-'99 were the only water cooled ones and that he looked up a 2000 one and it said "air-cooled" in the computer.
There WAS a recall on the early ones too but that's all I remember about them. OIL COOLING would be the way to go. That's what all the heavy-duty commercial units are on buses and over the road trucks. Something always struck me wrong with putting water in a alternator.

SoundAdvantage
08-22-03, 09:46 PM
No, you're right they ALL don't, some go WAY SOONER! ;)

To be honest Brett, the Northstar was the ONLY engine from Cadillac that I could NEVER depend on certain things happening at certain points during its life. Failures tended to be sporadic as hell and definately happened in groups depending on manufacture dates. This, definately made me feel that the production procedures were constantly in a state of flux. We had different failures in different groups of engines from day one. And I know I mentioned it here before but just in case anybody missed it, there are Northstar failures under investigation right now that you guys have not even HEARD of yet. One I mentioned before was a block cracking problem that is being seen in an aweful lot of engines and there's supposedly NO EXPLANATION for it yet. Yes these are in higher mileage engines (approx. 150K miles) but there are a lot of Caddys out there with that kind of miles on them too.
I will continue to say that even though the Northstar is an awesome engine when it's running properly, I DO NOT trust it's long-term reliability.
And bearing that in mind, I have to point out that Cadillac has a very poor track record with its aluminum engines and it is probably the one largest reason for their having such a poor reputation in the marketplace.
That, and their going to FWD has been a HUGE weight around their neck.
Hopefully, their moving back to RWD signals their desire to get serious in their supposed target market. Now all they have to do is put a better engine in their cars.

Kevin, Does this mean we will all have to wait for 2010 to roll around before we can buy a "New" Cadillac that can get us to and from work on time? :spin: How difficult would it be for Cadillac to Install the LT1 under the hood of a STS or the Eldorado and make them RWD cars?

Brett
08-22-03, 10:04 PM
I read somewhere, not sure where, that the "new" RWD version of the N* has forged pistons and crank, if true thats a good step.

Katshot
08-22-03, 10:30 PM
I wish I knew why Cadillac has such problems with engines.

sunrise
08-28-03, 03:19 PM
I have one of each and had to get in on the discussion. LT1s had up to 330HP net. Optispark is probably it's worst feature. Beyond that it is a great engine. Northstar 300HP is in my wife's 97 Concours with 124K and runs well, just passed California emission "Test Only" test. Yes, it leaks some oil, burns some oil, but otherwise its runs well. As for the comparison, the LT1 wins hands down on power and torque. It is also far less expensive to maintain. But that is not why I bought a Cadillac. For all of it's weaknesses, the Caddilac still represents, in my opinion, the best bang for the buck in it's class. And the same can be said for the Corvette.

96concours96
09-06-03, 05:28 PM
OK,
being an owner of both an LT1 and a N*, I can safely say that racing the two, my Concours beat my LT1. Powerwise, the caddy has my impala beat. The exact specifications for an LT1 are 260 HP, and 320 ft/lb of torque. My Concours is pushing 300 HP and I believe 300 ft/lb of torque. Granted, these engines have a difference of 1.2 liters between them, but the Caddy has the edge. Only reason - 32 valve dual overhead cam. My LT1 impala has a much simpler, rather antiquated, push-rod approach to itself. To tell you all the truth, I'd rather have my LT1....Only because an idiot backyard mechanic like me can work on it - and parts don't cost a fortune. I love my N*, but I have to go the cheaper route :crying: .
Later!
Jason

Katshot
09-07-03, 08:18 AM
In "stock" trim, the Northstar equipped cars WILL dog the Fleetwood for sure. They should either beat, or equal the SS. BUT.........it is VERY easy to boost the performance of the RWD Fleetwood and Impala SS compared to the FWD Northstar cars. So if you intend to leave the cars TOTALLY STOCK, an ETC or STS would be the hot ticket for performance. The Deville Concours will be a few ticks slower due to weight and tuning.

wake
09-19-03, 10:24 AM
The LT1 that's used in the Fleetwood is a downgraded version of the LT1. So let's just compare the Northstar to the LT1 without the downgrade. 300 horsepower..

So which engine is more powerful?

I'm not too sure about the low-end torque on the LT1. The LT1 (92-96 Corvette) and the L98 (85-91 Corvette) had the same 0-60 numbers. BUT - the 1/4 mile was better for the LT1 powered Vettes.

L98 Vettes were faster off the line and won most stop-light races. In fact, the L98 is quicker off the line than the current LS1 powered Vettes.. So I don't know how powerful the LT1 is down low. But I know it's powerful up high...

Now the Northstar is very powerful up high as well...

I've had variants of all three motors... I own a 96 LT1 Corvette as a weekend car, a 94 NS Eldorado as a daily driver, and in the past I had an 88 IROC with the Tuned Port Injected setup (305 instead of 350) but same setup as the L98, and a 97 Trans Am with the LT1 as well...

My 305 TPI IROC was quicker off the line than my LT1 Corvette or Trans AM, but only until about 4000RPM where it runs out of breath due to the long runner design... It's great for low end torque, but bad for high RPM HP... You can feel very noticably the car slowing down after 4000 RPM...

The LT1 wakes up after 3500RPM very nicely compared to the L98 and runs nicely up to about 5700RPM... The one thing I notice though is when I hammer the LT1, you really feel that it should be shifting when it does... You want it to shift because you just feel that it's, "time"...

On the other hand, the Northstar runs very comfortably up to the redline... It feels like it could spin faster and just sounds so happy at redline, where a conventional push rod motor is probably at the edge of coming apart (valve float, deflection, etc)...

There's no doubt that my Corvette is faster with 1.1L more displacement, more usable torque down low, and 300+ lbs less weight to move around, but the DOHC design of the Northstar just feels better at the high end...

For 6 years (90-95) the Corvette could be ordered with the ZR1 package which most people know for the LT5 DOHC motor... The feelings described by those lucky enough to own one are very similar to those who are enthusiastic about their Northstar powered cars... Most notabily, there nothing like hearing these motors, "sing" at redline... :D

CadiJeff
02-19-04, 04:00 AM
Kevin...... maybe you can help me out with a question:

I once heard that the metals used to make the NorthStar between the block and heads or something like that, were not comon metals, they repel each other, and after years of use (5-8 or something like that) they start seperating or something and it ruins the engine....... ever hear anything about that? How come I don't hear about it anymore?


This sounds like confusion b/w cadillac engines. The only thing I have ever heard similar to this is with the early ht-4100s, the problem was caused by the the temp expansion difference b/w the aluminum block and the cast iron cylinder liners, in over heating stuations this issue caused a seperation b/w the liner and block causing the coolant in the block to enter the cylinder and mix with the oil wich is obviously a "bad" thing. As I understand it this issue was later "fixed" in the later 4.x series engines with better seals b/w liner and block, as well as a recomended GM approved sealant in the coolant to prevent corosion of the seals. As for the northstar the cylinder liners are not seperatable so this is not supposed to be an issue.

156MPH
02-19-04, 11:53 AM
I thought I read somewhere that a Northstar and a LT1 are very much alike in design,I thought I heard it called a baby LT1?

gothicaleigh
02-19-04, 12:33 PM
Other than both engines being V8s, I don't think there is much in common between the two.

This thread just won't die, will it?

The two engines go about doing their job in completely different ways and both hit their marks very well. The N* is a technological marvel that has been refined to the point of almost being over-engineered (the new ones in the SRX and XLR have smoothed out the previous generation's quirks and bumped output to 320hp). The LT1 accomplishes it's purpose through brute force, it exists to get the job done.

156MPH
02-19-04, 03:12 PM
new post idea.4-6-8 vs the LS-6........:)

gothicaleigh
02-19-04, 03:26 PM
Ooh.
My bets on the 4-6-8. ;)

BeelzeBob
02-19-04, 10:30 PM
Kevin...... maybe you can help me out with a question:

I once heard that the metals used to make the NorthStar between the block and heads or something like that, were not comon metals, they repel each other, and after years of use (5-8 or something like that) they start seperating or something and it ruins the engine....... ever hear anything about that? How come I don't hear about it anymore?


This sounds like confusion b/w cadillac engines. The only thing I have ever heard similar to this is with the early ht-4100s, the problem was caused by the the temp expansion difference b/w the aluminum block and the cast iron cylinder liners, in over heating stuations this issue caused a seperation b/w the liner and block causing the coolant in the block to enter the cylinder and mix with the oil wich is obviously a "bad" thing. As I understand it this issue was later "fixed" in the later 4.x series engines with better seals b/w liner and block, as well as a recomended GM approved sealant in the coolant to prevent corosion of the seals. As for the northstar the cylinder liners are not seperatable so this is not supposed to be an issue.


This comment could not be further from the truth...

There is no real issue with the dissimilar metals in the 4.1 engine causing coolant to enter the cylinder or anything like that. The wet, removable cylinder liners of the 4.1/4.5/4.9 engine seal to the crankcase at the bottom with an o-ring and at the top with the combustion seal of the head gasket. In addition, the head is sealed to the perimeter of the deck face of the block by the head gasket. There never was and likely never will be an issue with the seal of the liner to the block at the bottom and the seal of the liner to the head at the top. Those areas were pretty bulletproof. No coolant entered the cylinder and the oil thru those areas. The leak area associated with failures of some early 4.1 engines from 82 and early 83 had to do with the seal of the head gasket between the head and the block deck surface along the inner edge...where a coolant seepage could contaminate the oil causing abnormal wear of the cam lobes and distributor gear due to the contaminated oil. The seepage in that area was very minor even on worst case situations and had little to do with the bimetal construction of the aluminum block/iron head. The issue was the stability of the deck surface at that location from a structural standpoint due to movement as the block thermocycled. Later engines in that family had structurally enhanced block deck faces along the inner edge as well as improved head gasket material that could withstand the movement better.

All the engines had the coolant supplement/sealer installed at the factory...the issue was the lack of cooling system maintenance with the aluminum block and the lack of replenishment of the coolant supplement in the cooling system. Cadillac and GM is not the only company to use the coolant supplement/sealer. The company that makes the product (and also markets their own line of sealant under the BarsLeaks brand) sells and ships to almost every engine maker on the planet....!!! It is a very common item particularily with aluminum engines due to possible porosity in castings that shows up during thermalcycling of the engine in the field.

BeelzeBob
02-19-04, 10:33 PM
I read somewhere, not sure where, that the "new" RWD version of the N* has forged pistons and crank, if true thats a good step.

Not totally accurate. The crankshaft in the Northstar engine (both the FWD and the RWD versions) has been changed to a forged crank instead of the cast nodular iron crank used from 93-03.

The pistons are cast aluminum, not forged in all versions of the Northstar....FWD and RWD.

CadiJeff
02-20-04, 02:03 AM
This comment could not be further from the truth...

There is no real issue with the dissimilar metals in the 4.1 engine causing coolant to enter the cylinder or anything like that. The wet, removable cylinder liners of the 4.1/4.5/4.9 engine seal to the crankcase at the bottom with an o-ring and at the top with the combustion seal of the head gasket. In addition, the head is sealed to the perimeter of the deck face of the block by the head gasket. There never was and likely never will be an issue with the seal of the liner to the block at the bottom and the seal of the liner to the head at the top. Those areas were pretty bulletproof. No coolant entered the cylinder and the oil thru those areas. The leak area associated with failures of some early 4.1 engines from 82 and early 83 had to do with the seal of the head gasket between the head and the block deck surface along the inner edge...where a coolant seepage could contaminate the oil causing abnormal wear of the cam lobes and distributor gear due to the contaminated oil. The seepage in that area was very minor even on worst case situations and had little to do with the bimetal construction of the aluminum block/iron head. The issue was the stability of the deck surface at that location from a structural standpoint due to movement as the block thermocycled. Later engines in that family had structurally enhanced block deck faces along the inner edge as well as improved head gasket material that could withstand the movement better.

All the engines had the coolant supplement/sealer installed at the factory...the issue was the lack of cooling system maintenance with the aluminum block and the lack of replenishment of the coolant supplement in the cooling system. Cadillac and GM is not the only company to use the coolant supplement/sealer. The company that makes the product (and also markets their own line of sealant under the BarsLeaks brand) sells and ships to almost every engine maker on the planet....!!! It is a very common item particularily with aluminum engines due to possible porosity in castings that shows up during thermalcycling of the engine in the field.
In actuality I personally have seen this problem with the o-ring in two cars the first was a 1984 fleetwood coupe (great looking car) it had over heated and one of the o-rings gave out, the engine still mixed coolant and oil even after a head gasket replacement. The second was a worn out 1982 seville, I believe this one was primarily due to a lack of maintanence.

nerisauto1
02-20-04, 03:56 AM
No, you're right they ALL don't, some go WAY SOONER! ;)

To be honest Brett, the Northstar was the ONLY engine from Cadillac that I could NEVER depend on certain things happening at certain points during its life. Failures tended to be sporadic as hell and definately happened in groups depending on manufacture dates. This, definately made me feel that the production procedures were constantly in a state of flux. We had different failures in different groups of engines from day one. And I know I mentioned it here before but just in case anybody missed it, there are Northstar failures under investigation right now that you guys have not even HEARD of yet. One I mentioned before was a block cracking problem that is being seen in an aweful lot of engines and there's supposedly NO EXPLANATION for it yet. Yes these are in higher mileage engines (approx. 150K miles) but there are a lot of Caddys out there with that kind of miles on them too.
I will continue to say that even though the Northstar is an awesome engine when it's running properly, I DO NOT trust it's long-term reliability.
And bearing that in mind, I have to point out that Cadillac has a very poor track record with its aluminum engines and it is probably the one largest reason for their having such a poor reputation in the marketplace.
That, and their going to FWD has been a HUGE weight around their neck.
Hopefully, their moving back to RWD signals their desire to get serious in their supposed target market. Now all they have to do is put a better engine in their cars.
You guys are all old farts that think 100k is hi miles!! 100k is just being broken in for Northstars!!Just about all of the Caddy's I get, Im a used car dealer, and my current daily driver is a 93 Eldorado ETC with 145k, last one? guess what? another 93 Eldorado ETC with 187k, only problem was the pan gasket started leaking and I didnt feel like fixing it. Both cars I put K&N air filters, air box's removed, makes an amazing sound, sucking the air through the filter soo violently, when im rolling and floor it, it kicks down to first burns rubber and scares the crap out of people walking down the street, the kids hold their mommy's hand real tight and look like wtf? Is that a Cadillac? As I pass the exhaust makes that snarl sound they make,lol, I love it! both could do G-tech timed, 0-60 under 6 seconds, actually the 145k ETC does 5.7 secs with traction control/ABS fuse removed, quarter mile 14.1 secs!! last one did 5.9/14.6. Now I beat the hell out of them with no mercy, I admit I have a lead foot, and pay for it with a crappy 10.4 miles per gallon but ahh fuggit, its fun! Now the Caddys weigh roughly 3800lbs or more, are faster than Vette's of the same year,and newer,of course the LS1's will spank the Caddy but hey ive only got 300hp.... (excluding LT4/5)Im talking about the ones that have L98/LT1. But these cars (Caddy's)are amazing, like i said i beat them with out worrying about breaking, and I have never had a problem with any of them, all high mile 140K cars. Im a dealer and get a lot of used trade ins, and the Caddy's even the older 4.1,4.5,4.9's are good engines, i know about the headgasket problems they say they had, but I think when someone (usually old fogey's)im 30<has a problem they take the car to the dealer or their "great mechanic" to fix it, then rapes them for headgaskets when all it is, is probably a thermostat or something stupid like heater control valve, trust me, I ran a shop for about 6yrs, and um...we um..found things perfectly broke...QQwink, wink...People some how feel good paying money for something (wink, wink)"broke" to be fixed, and the more they pay the better they feel..trust me...i know..lol...But I take my hat off to GM/Cadillac for making an awesome engine, that pulls like from 3k rpm's till you either let off, or it hits the redline! mine by the way shifts at 6500 and chirps loud,lol, maybe it was my imagination, but it once shifted at 6700! I took it to 135 the other day with my new PePBoys FuturaVR 225/60/16 tires, only 74.00 each! but didnt have enough room to go faster, or need to get a ticket..... I believe it will do the 150 if not more, My understanding is the top speed is drag limited and not electronically limited to 150, if I am mistaken please let me know, reply only if you actually have gone over 150. Oh, getting back to the point....the LT1 is 5.7L the Northstar is 4.6L, yeah it has dual overhead cams but there is a 1.6L displacement difference. Make the Northstar closer to 5.7L or hey even a 5.0L! It makes 300-320 at 4.6L at 5.0L ?maybe 325-375? at 5.7L 350-425? I believe it could, but I know they would have to make a new block, since the northstar, from what I read can't be bored much if at all, but what if, i say! and it will in every instance spank the LT1 in smoothness and sheer revability/durablility, thats what makes the northstar shine! It loves to rev, and not just rev, do it smoothly and pull so STRONG/HARD! Ive had vettes,mustangs,driven a lot of cars and can drive just about anything i want, but what do I drive? A bright RED american Northstar powered Caddy Eldorado ETC, by the way there are pics in the Eldo pic part of the forum if your curious what the car looks like that spanks stock and mildly modified 5slows,older vettes, camaro's many ricers all over Philly, Pa while looking classy doing it!
P.S. Im a Chevy man all the way, dont get me wrong! I have a GMC sierra GT 350 pickup, Chevette with 4.3L truck engine, always be and always will be, but I'm in love with Caddy Northstars and my current biach is a drop dead pretty 93 Eldorado ETC!!

BeelzeBob
02-20-04, 01:16 PM
In actuality I personally have seen this problem with the o-ring in two cars the first was a 1984 fleetwood coupe (great looking car) it had over heated and one of the o-rings gave out, the engine still mixed coolant and oil even after a head gasket replacement. The second was a worn out 1982 seville, I believe this one was primarily due to a lack of maintanence.
I would certainly concede to the fact that the bottom o-ring "could" be melted away in the event of a serious over heat and it "could" leak possibly....but that was NOT an epidemic problem if a problem at all. In fact I have seen a number of engines deliberately built without the o-rings around the base of the cylinder liners for test that never leaked and never caused a problem because the seal between the bottom of the cylinder liner flange and the block was so tight. Honestly, the o-ring "could" leak but my guess is that the head gasket caused the problem in both cases.

My suspicion would be, in the example presented, is that the mechanic disturbed the cylinder liner when the head gasket was replace and trapped dirt/debris/sediment from the cooling system between the lower flange of the cylinder liner and the block and that created a leak path when the new head gasket was installed..... I have seen this failure mode many times in the past. Basically come form carelessness and lack of due care by the service tech/mechanic and/or lack of understanding of the cylinder liner sealing and construction methodology. If the liner seats squarely into the block with no debris or dirt trapped between it and the block surface then the o-ring seal is actually a redundant seal. In any case, if the coolant sealer is used it will STILL usually stop any coolant seepage in that area.

I have never seen a 4.1/4.5/4.9 with the original coolant loss/coolant leak problem caused by the o-ring at the bottom of the liner or the seal between the liner and the cylinder head itself. Those incidents are almost without fail the issue of the head gasket to the aluminum block deck face along the inner rail. The liner o-ring problems are then a secondary failure due to the original service.

The point being that the bimetal construction was not the root cause of the problem at all. Nothing to do with the metals corroding or galvanic action or anything like that. And nothing to do specifically with the wet liner style of construction. It was a gasketing issue and a structure issue between the block and the head at the deck rail surface.

Incidentally....many many 4.1/4.5/4.9 head gaskets are blamed for "coolant in the oil" when in reality it was the intake gasket leaking at the corners of the manifold where the coolant passage is. Since the intake gasket was replaced at the same time the head gaskets were the problem gets fixed...and misdiagnosed as a head gasket problem when it was the intake gasket.

CadiJeff
02-20-04, 05:32 PM
I agree that it was not an epidemic problem but it did exist, a cadillac mechanic I talked to said that the o-ring "problem" had two causes. The first was old antifreeze eating the seal, and the second was that given the first issue an engine overheat can "do in the seal" due to expansion difference b/w the metals and he further explained that the seal had to be weakend first. he also stated that it was almost exclusively an issue with the "standard mount" version of the 4100 and was not a problem w/ the tranverse mount 4.x engines.

CadiJeff
02-20-04, 06:10 PM
Also don't get me wrong I have owned and driven sevral 4.x engines and with the exception of the standard mount 4100 I loved them all and the were all reliable and still run well. (the reason for the exception is the power/wight ratio in my opinion it was inadequate to move a 4000 lb vehicle)

By the way to actually be on topic with this thread I believe that the northstar is the superior engine for a couple of reasons.
1. Gas mileage
2. higher rev limit(stock all else equal the northstar would be faster)
3. thrust to weight ratio is in favor of the northstar as well (engines only)

the only draw back is the lack of performance parts for the northstar

BeelzeBob
02-20-04, 09:31 PM
BTW, The Northstar was originally an Oldsmobile engine design. Olds ran out of developement money and Cadillac, (needing an engine of their own at the time) picked up the design ball and kept throwing money at it until they got it to work. It's a fairly good design but has been hampered by typical GM bean-counter cost-cutting efforts, which has produced a very similar situation to the HT4100.


Geez, I go back and read the early parts of this string and come across this gem of mis-information. Don't know your source Katshot (and don't want to know it...LOL) but it is dead wrong. Completely. Absolutely. Olds had absolutely NOTHING to do with the design, development or original concept of the Northstar engine. It was done completly inhouse by Cadillac Powertrain engineers at the Clark Street facility...original home of Cadillac. I was there and I know. In fact, I even worked on some of the early proof of concept packages and test mules that were used to evaluate what type of engine the Northstar would eventually be. There were a lot of options and a lot of things were considered...but....OLDS was not part of it at all. The Quad 4 has often (mistakenly) been assumed to be the precedent for the Northstar engine but it had absolutely no impact on the design. The engines are alike only in that they are both DOHC engines. And to squelch another, similar, rumor, Warrren Johnson did NOT even know about the Northstar engine until he saw it in a Cadillac one day.... Someone "reported" that WJ did the engine development for the Northstar engine.....LOL

I personally know the designers of the Northstar engine and watched them design it in person on paper. Even back at the napkin and pencil stages. Those guys would be pissed if they knew someone thinks that OLDS designed the engine.....LOL

Vesicant
02-21-04, 10:06 AM
bob, have you heard of a lot of people with engine mount's wearing out ? I borrowed a deVille, and had to replace the engine mounts on it otherwise it would have been in terrible trouble.