Need feedback with motor issue

[Rocket 1]

Got a new aluminum motor put in my car,keep in mind the only thing i changed from previous motor was had to get a new ditributor due to tall deck,now heres whats goin on fired motor up runs fine good oil pressure until about 8 to 10 minutes of running then oil prs starts going down and bouncing back up and eventually loses it,not sure what to think any suggestions please.ps i run a 4 stage dry sump system.

[twisterf5]

Got a new aluminum motor put in my car,keep in mind the only thing i changed from previous motor was had to get a new ditributor due to tall deck,now heres whats goin on fired motor up runs fine good oil pressure until about 8 to 10 minutes of running then oil prs starts going down and bouncing back up and eventually loses it,not sure what to think any suggestions please.ps i run a 4 stage dry sump system.
sounds like the pressure regulator in pump is stuck open

[racin6mod]

I agree with twister also had a bad oil filter do the same thing once the da m thing would suck in and squeeze off the oil flow you could shut the motor off wait 5 min refire to good pressure and then it would start bouncing around again. once I changed it we had no more trouble.

[SLM98]

Does the pump have a high volume pressure section. Aluminum engines need more volume because of more internal pressure losses.