davefr wrote: d> I'm curious where the Northstar V8 fall in terms of overall d> performance and reliability. Does this engine have a good reputation d> (like GM's 3.8) or is it a dog? (like GM's 3.4)
d> Does it have piston slap?
d> Is there much in the way of aftermarket mods available? Any good d> forums that talk about this engine?
The Northstar has been around for a little over a decade now. It's the direct descendant of the 4.5 and 4.9 Caddy engines that were supposed to remedy the gutless (for a big Caddy, anyway) 4100.
It's a high revving aluminum engine and as such is extremely sensitive to coolant maintenance. In 1996 they came from the factory filled with the 'orange' DexCool which almost eliminated maintenance, at least up to 100K or so.
The 4.6 liter has two versions, the 300HP in the Concours, STS and ETC, and the 275HP in the other Caddies. The Aurora had the baby NS at 4 liters. Their potential is mostly at higher speeds.
I'd say it has a good reputation, although repair costs are a bit on the high side, unless you tackle them yourself.
There is not a lot you can do to it, maybe opening up the exhaust a little bit. For earlier models (OBD-I) you can get a "chip" but basically what it does is it gets rid of the speed limiter. A supercharger has been in the works for quite awhile. Some guys on the forums below did put their Caddies on the bottle (NOS).
These are two excellent forums dedicated to contemporary Cadillacs:
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and
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Check'em out.
-Bela