: Future Development of the Northstar

07-06-07, 04:14 PM
I am new to the forum so I hope this is not a subjuct already discussed.

With the advent of the 302 HP 3.6 V6 the very expensive V8 option (formerly $9,500 on the STS) for an additional 18 HP really begs the question - why bother? I feel that my STS is more than equal to the European and Japanese competition but to continue the recent Cadillac resurgence the Northstar needs to be upgraded to 370-390 HP. Given that the bore centers are at their limit (this is why the V series Northstar had to drop bore to gain wall thickness) other approaches will be needed. The 3.6 V6 seemed to realy respond to direct injection (and probably a thousand other small refinements) and the higher CR that DI allowed. Does anyone have news about what will happen with the Northstar?

07-08-07, 01:38 AM
I havent heard anything new on the Northstar. My understanding is that the upcoming V12 will be the next step up from the DI V6.

07-08-07, 08:52 AM
Thanks. Can you direct me to any tech articles on the V12?

07-08-07, 11:07 AM
:bouncy: :bouncy: :bouncy:

I doubt that there won't be a V8 in the STS lineup,
I bet they will borrow the Z06 engine...

07-08-07, 04:47 PM



Whether it comes from the US or Australia, the end goal is two V6 engines fused together to make a cheap but powerful V12.

07-08-07, 08:24 PM
I have read that the Northstar is an old outdated heavy engine and isn't long for this world. I doubt if true GM will be putting any money into reviving it to make it more competitive.

07-08-07, 08:35 PM
I've read in some of the car magazines that GM is developing a new family of V8's (with a variety of displacements?) called the "Ultra" V8 for use in Cadillacs and other high end models.....and they're supposed to have much higher HP and TORQUE numbers than the Northstar...enough to be competitive or beat the latest BMW and MB V8's which have HP in the 360-380+ range.....

07-10-07, 12:51 AM
Not trying to ruin anyone's day.. but the STS is DEAD after 2010. Cadillac needs a top end car to replace the STS and DTS, and will be combining the two.. While the Audi brand already has the superior A/S8 to compete with the 7series, Cadillac has not yet released a true competitor to the HIGH-END segment. The XLS will be replacing the STS to fill that void.. while the CTS will take on the 5series and Audi A6 variants including a coupe for the Cadillac marque and a wagon. The next BLS will be positioned via its new Alpha platform skeleton to compete and BEAT the 3series and A4 variants. Also look for a A3 and 1series competitor from Cadillac based on th Alpha platform. Looks for a CTS inspired look for the next SRC and a smaller sibling based on the Theta platform called BRX. The XLR get's a softer more classical form in 2010 when the C6 Corvette morphs into the C7. Lastly... I'm also hearing that instead of Saab getting a Kappa (Solstice/Sky) variant... Cadillac will be getting one with a more luxurious edge, styled so different that it will be not recognized as a Saturn/Pontiac sibling... also with a D.Injected 3.6L under the hood, possibly turbo-ed to make 400HP.

Engines for the entire Cadillac line will be a continuation of excellence that was started by the soon to be defunct/replaced North-star... Rumor has that by 2009 the new Ultra V8s will be put in place of the NS, giving the Cadillac line a V8 base engine of no less than 370HP... soldiering on to at least 600HP naturally aspirated, employing such innovative technologies as Direct Injection, and Hybrid drive to bolster both fuel economy and power... Audi is hitting us right back with a slew new products as well... and after seeing the 550HP possibility of the upcoming RS6... Cadillac had best stick to the rumor of the 600HP LS7 engine being in the CTS-V... While BMW had better boost the output of the M5 and M6....
it would seem that for model year 2010, Cadillac second phase of it's revitalization will be implemented. The STS and DTS are essentially redundant in this new phase since the model for Cadillac is the one from BMW. As follows:

Alpha Platform = 3series
CTS= 5series
XLS= 7series
XLR= 6series
SRX (?)= X5
Escalade= Range Rover (non BMW)

Each car will be getting variants. For example the CTS will have a convertible and a coupe. The XLS will be a V8 and V12 version. The Alpha will be a 3series competitor with a Sedan, convertible and coupe. All cars will be offered with optional AWD and higher end ones such as the CTS, XLR, XLS, SRX, and Escalade will have Hybrids

Got this from my Caddy Dealer... Hope he is correct. The STS will be done by 2010 as will the DTS. V-series will possibly skip model year 2009.

Dr. Design
10-01-07, 04:50 PM
From what we understand, the Northstar motor will be eventually replaced by a new global V8. This should be in conjunction with the new DTS/STS Sedan around 2011-12. As for the price difference between the DIV6 option and the N*V8 option...well I think Cadillac knew what they were doing. Seems like they will let it slowly phase out without calling too much attention to itself while doing so.

cmicasa - I dont think you will see Cadillac release anything using the Kappa platform. Nothing against the platform, but Cadillac division must answer to a higher level of expectations. However your information is very SOUND!! Seems like you have very good intel.:highfive: We are quite intrigued by the future Alpha V-Series engine!! The idea of Bi-turbo seems pretty cool.

Dr. Design

c5 rv
10-01-07, 10:06 PM
Interesting details from the UAW contract:


10-04-07, 03:40 PM
something old becomes something new...with gas prices predicted to stay at 3.00/gallon or more for the forseeable future, turbo charging will be used across the board by any engine designer with an eye toward: output,effeciency, and most importantly, fuel economy.

as decent as the n/s engine is, let's not forget the design goes back 15 years!! it had a mild makeover around 97/98 but it's pretty much the same from the beginning. can you imagine the improvements in head, friction reduction and operating effecciencies that have ben acheived since 1992?

the introduction and use of a v12 does make alot of sense from a production standpoint: it could be based on the 3.6 di...having said that, it's hard to imagine anything but a "halo" car having a a 12cylinder engine. variable displacement v8's, variable vane turbo engines, the hybrid engine that gm is currently testing that combines compression and ignition combustion for much better fuel economy and performance seems much more likely and advisable for caddy's mainstream powerplants.

time will tell.....



Curious George
10-05-07, 04:52 PM
Actually, the Northstar got a major upgrade in 2002 when it was adapted for use in rwd cars (initially the XLR) and awd vehicles (initially the SRX). In late 2004 it appeared in the 2005 STS, and then in the STS-V. Follow this link to learn more about the Northstar than you'll ever want to know and to be really impressed with the prowess of Cadillac engineering. http://autospeed.com/cms/A_1569/article.html

The current Northstar is still state-of-the-art, or would be if GM adapted it for Gasoline Direct Injection. But it's too expensive to manufacture, it seems. The Ultra V8 will be interesting to look at when it appears.

10-06-07, 01:29 PM
i stand corrected, somewhat....of course, the n/s was changed dramatically from a packaging standpoint when they changed over to rwd...most of the increase, if not all was due to the improved flow of the intake and especially the exhaust systems....and this isn't from me...this comes from one of the original engineers on the n/s development team. i have no gripe with the n/s motor: it's a well rounded powerplant: lots of grunt down low and good power on top.

i also concur that the addition of d/i would increase it's numbers....but....there are some real breakthough technologies that are being testing as we speak....i believe the acronym is hccs which is the hybrid (my term) system i alluded to. ford tested a similair system in ups trucks back in the 70's but couldn't get it to work for every day use. the system incorporates both compression ignition (diesel) and spark ignition for greatly improved fuel consumption. all this is only possible due to the advancements made in the use of engine control systems since the advent of the digital age.

andas i said at thebeginning of my first post on this subject; what's old is new and that also applies to the d/i technology...that's also been around since the 70's. mitsubishi offered it on a home market 4 banger engine but could not get it certified for use in the states....again, it's only been since the introduction of digital fuel magement systems that the driveability problems of surging and erratic power delivery has made d/i usable on modern engines. it's also important to remember that d/i was first used as a fuel economy system, not for bumping up the power numbers. it's a good, decent sytem for bumping up the numbers but there are other systems such as turbo charging that have benefited greatly from the advancements in metalurgy and the fuel management systems. it's pretty hard to beat t/c for improving all aspects of an engine's performance: fuel economy, power (both in the ultimate numbers and for usable every day increases in power) and by allowing theuse of smaller displacement engines to make the same power as a larger motor.

caddy may indeeed produce a 12 cylinder engine but it sure won't be their bread and butter motor, like the n/s has been for over 15 years.


Curious George
10-06-07, 02:32 PM
i believe the acronym is hccs which is the hybrid (my term) system i alluded to. ford tested a similair system in ups trucks back in the 70's but couldn't get it to work for every day use. the system incorporates both compression ignition (diesel) and spark ignition for greatly improved fuel consumption. all this is only possible due to the advancements made in the use of engine control systems since the advent of the digital age.
M-B calls this system DiesOtto (Diesel Otto cycle), and introduced it last month at the Frankfurt Auto Show in the F700 concept. Quoting Autoweek, "Despite its relatively meager capacity by luxury-car standards, the F700ís advanced engine punches well above its weight, with a 238-hp output that compares favorably with Mercedesí existing four-valve-per-cylinder 3.5-liter V6 gasoline and 3.0-liter V6 common-rail diesel units. With an electric motor designed to provide an additional burst of output under acceleration, the F700ís peak power tops out at a competitive 258 hp in hybrid mode. Torque is rated at 295 lb-ftóprodigious by four-cylinder gasoline engine standards.

Mercedes says itís enough to propel the F700 from 0 to 62 mph in 7.5 seconds. But even more impressive are its environmental credentials, estimated at more than 50 mpg with an extremely low carbon-dioxide output."

10-10-07, 09:25 AM
it's really interesting how there really hasn't been any "breakthrough" technology in the last fifty years or so in engine design...that's a pretty harsh statement on the surface but all of the "add-on" systems have been around since the early part of the last century!! the refinements have been dramatic, of course, but it still shows the basic design of the internal combustion engine is pretty much unbeatable.

i knew i shouldn't have used hybrid to describe the hccs...even though it is a melding of spark and compression ignition. the hccs doesn't utilize any electric motors. it's an internal system that utilizes compression ignition under very specific conditions to maximize fuel economy, with some increase in power i would imagine...but the main thrust of the design is to better the f/e numbers.

toyota utilizes electric motors for the rear wheel propulsion on some of their sport utes...it's basically a fwd platform with the motors added on for some serious increase in grunt power when needed. the problem with that type of hybrid system is the weight penalty, between the batteries and motors it's alot of dead weight when running on two wheel drive.

i'm sure all of this technology won't see the light of day on any caddy any time soon...caddys' have a reputation for being rather conservative, imo, in their design philosophy....though the n/s did break some ground when it was introduced with the "limp home" feature in the event of a loss of coolant...you could drive for 50 miles with reduced speed, to make it home. one interesting tidbit on that feature: when the limp home mode was activated due to the loss of coolant, the engine oil HAD to changed immediately after the repairs were made. major stress was put on the oiling system to make up for the loss of coolant.


10-10-07, 01:36 PM
Regarding development of the internal combustion engine, has anyone heard of the Scuderi Air Hbrid engine? Here is the link:


10-16-07, 01:29 PM
whew...that's way above my level of comprehension....some of the explanations i could better understand after viewing the animations. i do remember that mazda developed a miller cycle engine (miller was mentioned in the explanation of the technology used) some years back...i think they put it in their "luxury" sedan that was supposed to be a full car line off-shoot from mazda but they ran out of money or the market dried up.

i know that gm was testing an add-on system using compressed gas in a stand alone cylinder that would launch a vehicle (mainly big sport utes or buses) from a dead stop to save fuel and cut down on emmissions. a tremendous amount of energy is required to launch a vehicle from a dead stop. this compression of air in one cylinder to aid in thepowerstorke of another cylinder seems to be what is at theheart of the scuderi design...at least that's how i understand it.

it does seem as though there would be some parasitic loss of effeciency since one cylinder seems to be "along for the ride" so to speak...as i said...
i don't fully grasp the full concept...one thing though about different engineering designs like this: it must be testied in the real world: a production type engine driving under all conditions and meeting federal emmission laws for 50,000 miles....that's a tall order...orbital, a austrailian company that developed a hybrid engine design that combined two stroke features (which immediately solves the problem that the scuderi engine tries to solve in a different fashion) with four stoke features for excellent power to weight and forincreased fuel economy....but they couldn't get the engines to pass the certification process in u.s.

it definitely sounds like something that would at least be feasible for power generation as a static power plant....time will tell if we hear more about it.


10-16-07, 02:47 PM
Everything in engine developement in the last fifty years has been in the area of implementation of what everybody knew had to be done but the means wasn't with us yet. Direct injection has been around since WWII but we're just now adapting the technology that makes it practical. DOHC is now common so the progression will be to desmodromic valve gear and then electronics and solenoids. There were 1.5L engines in 1949 developing 550HP reliably. The oldtimers knew what had to be done but the everyday implementation is the sticker.