Z3 Highlight/Lowlights of 2.3, 2.5 & 2.8

[oldoutboardjim]

Depending on the year (1997-2000), the Z3 was available with several 6 cylinder engines (besides the "M" 3.2). Are any of these engines exceptionally good or bad, and if so, what are the traits?
Thanks in advance!

[celluje1]

The 2.3 is really a 2.5 badged differently for the Europeans as they tax based upon litre. all 3 of these engines are very close. Stroke and bore are really the difference. 2.8 has a larger bore. The 3.0 has a different stroke and bore than the 2.8. It all depends on what you want to do with the car. I started at 170hp and roughly that was 141hp to the rear wheels. I now have it up to 168HP to the rears without touching anthing major in the engine. If you are looking for a car that you can put a supercharger on make sure that you get a stick. the engines themselve are strong straight six's.

If you are looking to do M50 plenum conversion for 30hp I beleive that the 2.8 is the way to go. The 2.3 is the most limited engine there is, but it is a blast to drive. Plan to replace the water pump as soon as you get if for insurance reasons. I am just finishing up the project and debating on what I may or may not do next. Any question about upgrades to a 2.3 just drop a line. IF I had it to do over probably would have gone with the M.

Upgrades done to my car.

Suspenion all/ including bushings, sways, control arms
Brakes - Rotor SS lines
Rims - 18"
CIA
Coolant system - overhauled with Zionsville
Underdrive pulleys
Supersprint Exhaust from the headers back

[SUNZOUT]

There are also two 2.5 engines - the early M52 and the later M54.

Can't comment on which is better but other than cooling system issues I've not seen to many bad things said about any BMW 6 cyl engine.

check out the Z3 wikki for more details on the engines

http://en.wikipedia.org/wiki/BMW_Z3

[Bmwcat]

I have the 2.8L in both my cars and they are awesome. :thumbup: