: Stand-alone Northstar engine/trans for swap



Caddaleana
03-19-09, 09:48 AM
I'm building a 3 wheel vehicle (2 in back, one in front) using a 97 DeVille engine/transaxle as the drivetrain. I need to know if the original ECM can be used (modified?) to support engine and transmission operation in this new vehicle. I have the schematics, so I know what ties to the engine computer and to the body computer, the wire color code and sensor/device locations.

I'll be adding a separate, industrial grade PLC to do some things like speed sensitive, 3 wheel steering, body tilting and forcing turns by looking at differential wheel speed and pulsing the brakes. I started building a prototype vehicle using a less agressive powerplant, but figured I'd switch to the Northstar (mo power, plentful supply, cheap prices). The vehicle program name is "Caddaleana".

I'm in the process of pulling all the front end "skin" and extra stuff off the car right now, and other than lights and horns, everything is intact yet. The car ran fine into the shop, the only codes showing were loss of refrigerant issues, since the A/C system is trashed, but I won't need that system anyhow.

I'm brand-new to this site. It looks like a great place to fellowship with other "Gearheads". I'm looking for some guidance, from someone who's "been-there, done-that".

STSS
03-19-09, 10:33 AM
Not sure if anyone has "been there, done THAT"
I'm excited to see it if you get it to work.

My only advice is make sure the block has been serted/studded, or do that while the engine is out.

Caddaleana
03-19-09, 10:49 AM
Good advice, thanks! I've heard these engines are suseptable to head gasket leaks, is the bottom end OK, or should I do the mains too?

STSS
03-19-09, 12:26 PM
If you dont have a problem with the bottom end, and you dont plan to boost the motor, the bottom end is fine. You might want to check for leaks though, some require pulling the motor to fix. Here is a recent thread about replacing the rear main seal (case half seal) while the motor is out for HGs.

http://www.cadillacforums.com/forums/northstar-performance-technical-discussion/163751-rear-main-seal-install.html

If you do more searching about seals and leaks, Im sure you can find more info about what to change.

ps... since your budget doesnt seem too small (atleast I hope not with plans like yours) you might consider doing the HGs while the motor is out, even if they arent bad YET. I know I wouldnt pull a N* without doing them.

Caddaleana
03-19-09, 12:33 PM
I lov dis place!!! Great, thanks!

AJxtcman
03-19-09, 01:09 PM
You can contact me dirrectly for more information
cadillactuner@airfueltuning.com

Submariner409
03-19-09, 04:50 PM
Caddaleana, FYI the Northstar lower end is pretty much bulletproof....there are no oversized main or rod bearing inserts available and the crank cannot be turned, it must be replaced if a main or rod journal is scored. No cylinder boring, oversized rings or pistons either - except special order non-stock pistons.

The crank pulley torque is used to assure a friction clamping for the oil pump drive, so make sure that is done "by the book". You would not be the first to light off an overhauled Northstar and have no oil pressure.

Caddaleana
03-19-09, 10:20 PM
I appreciate all the info on the oddities of this engine. It sure ain't a small block Chevy, but that's what makes it appealing to me!

For this vehicle (the Beta prototype), I'm not planning to get very deeply into the engine or trans. At this point I'm concentrating more on the frame, cockpit, and running gear. My first task is to graft a cockpit and front wheel on to the front of the car (replacing the bumper), to get the frame/steering geometry correct, then "cut" the car off the back of the 3 wheel vehicle.

Next, I'll duplicate the mounting geometry for the subframe, and build the final frame structure to drop over the subframe, picking up the struts and four rubber mount points. It's sort of like building a chopper from an old Electraglide, you just use the old powertrain, pretty much as is, with some open exhaust headers, and drop it in a new frame, with some different sheetmetal and chrome, and ..... "Wallah" a $35,000 work of art! That's my plan, anyhow!