Sorry no one has replied to you yet. The Northstar is a very capable engine. Two versions of the mid/late 90's engines producer either 275 or 300 rear wheel HP in stock trim. They can also get 25 29 MPGs. Aftermarket builders can build them up to 1,000, and I have seen them with superchargers. The mid to late 90s Northstar is the favorite among performance engine builders due to its design. Checkout these radical Northstar engine buildups:
However, there is the head gasket problem with the Northstars up to the year 2000 that you must familiarize yourself with before you begin to consider putting on of them into a car or even before you buy a car that has one. This head gasket problem is actually head bolt problem. An imperfection in the factory design leads to a chemical reaction with the engine coolant used that causes the aluminum in the head bolt thread area to become soft over time. The head bolts pull up do to cylinder compression and the head gaskets blow due to a lack of head to block clamping pressure. Replacing the gaskets and re-torquing the bolts does not fix the problem because the bolts no longer have their ability to be seated in the block. Of all of the remedies out there, a racing head stud kit is the best fix and it is permanent. The way the studs are designed, they cannot pull free again. The stud kit will cost about $600. If you are willing to install a stud kit, the Northstar is hard to beat, but if you miss that step, you won't keep one together very long in a performance application.
If you own and Eldorado or Seville with a 1993 1999 Northstar and have a head gasket failure, its going to be a $2500 - $3,000 repair bill if a repair shop does the job right. This is due to the enormous amount of labor involved in dripping the engine/Tranny combo out of the bottom of the car, separating the engine from the transmission, performing the repair, and then reassembling the car. This is why there are such good deals out there on Eldorados and Sevilles of that era.
If the head studs are installed, these 300 HP engines can get 28-29 MPGs on the interstate and can live over 300,000 miles in performance applications. "Timing serts" or "inserts" are the other type of remedy for the lifting of the head bolts. These are the threaded block inserts that hold the head bolts in place. Installing timing serts is "okay" for non-performance applications (and is used in performance applications as well), but I strongly recommend the head stud kit available from places like Northstar Performance in Canada. http://www.northstarperformance.com/sgstuds.php
If the head bolt problem left unaddressed, 10 to 15 percent fail due to blown head gaskets in 50, 000 to 100,000 mile increments. Repair shops that are not "in the know" about these engines have done standard repair jobs on them and have had so many warranty returns in the past that they refuse to work on them. If you are going to have one repaired, ask them what they will do to prevent the head bolts from lifting in the future; if they do not know what you are talking about or do not mention "timing serts" or "head studs" chances are they do not know how to repair these engines properly.
The Northstar is a love it or hate it engine when it comes to performance. There are few performance parts available and they are expensive. However, head studs, cams, headers, and a custom tuned fuel injection system is all that is needed to make a very peppy and reliable engine that is still good on gas mileage.
From the factory, the 3,600 lb. 1995 Eldorado ETC does 0 60 in 6.5 seconds and corners like a sport car. It can easily be tuned with cams and performance program to do 0 60 in the 5 second range. I eventually plan to build one for autocross racing.
Cody G. Carson
--- In Cadillac_Performance_Association@yahoogroups.com, "jdascout" <jdascout@...> wrote:
> Hello Northstar members I have a question for you. What is the trans bolt pattern on this motor? is it similar to the BPO or the chevy pattern? I just saw a couple of them in the wrecking yard and started thinking, what about?