I've been searching through the forum to find any oil pump failure related data. It looks like most of the failures are due to or related to the pressure bypass valve getting stuck. There's also two separate threads reporting failure when the harmonic balancer is removed (replaced with an underdrive pulley) which is not suprising to say the least.
A friend of mine has also had the stuck bypass valve issue on a new build and fixed it by blocking the bypass and regulating pressure with a Peterson remote relief valve like on the bottom of this page: Peterson Fluid Systems : Pump Accessories
It might not be a bad way to go to head off these bypass valve issues? Coupled with a beefier harmonic balancer I guess...
If you have had any oil pump trouble, could you please post to this thread?
Pressure relief valve issues:
mr2daj - pressure relief valve stuck open
oil pump failure with pics
ttmiata - pressure relief valve (unconfirmed)
Savington - pressure relief valve
Rebuilt 1.8 with boundary gears and my oil pump failed :(
Arkmage - pressure relief valve stuck open (unconfirmed)
left field - pressure relief valve stuck open
dead oil pump
petrol - pressure relief valve stuck open
'Bout to drop the subframe (R&R oil pump the dirty way)
bbundy - pressure relief valve sticking partially closed when cold
Oil pressure high!
Underdrive pulley issues:
mazpr - shattered pump gears
Oil pump failure, pictures of destruction inside...
1.8 96-97, aluminum crank pulley (no harmonic balancer)
Other threads that may be of interest:
miatata - shattered gears (unconfirmed)
1.8L Oil pump Failure: Crank pulley question
jap import 1.8
the oil leak A/C bolt?
mention of a/c bracket bolt supporting oil pump