Recently did a frankenmotor with 220 cams in it. Using HLA's. The motor keeps going through them. Oil pressure drops when I accelerate as well and than rises to normal again. Could this be due to a couple collapsed lifters?

If the pressure is dropping the bypass valve in the oil pump could be damaged or just worn.

Also possible the pickup tube is not sealed properly (o-ring is bad/missing), or the screen is clogged, or the tube is cracked.

Did you use RTV on the pump housing to block seal? RTV is known to have little bits break away and clog the feed ports to the rocker shafts.

loose retainr bolts on oil pump gear plate wrong headgasket or crap inside the cam pluging pasages

did your camshafts come with spacers for the hla ? did you install them?

reground cams require spacers to compensate for the material removed.

I'll go with Ivan here, yeah did you check the oil pump? My EJ25D had a few screws that had backed out.

 

Also maybe you have a cracked pickup tube. I assume you're not low on oil, maybe your dipstick is reading wrong.

 

When I installed my Delta 220 cams I didn't have any HLA shims and after a few minutes when breaking in the cam everything was quiet and still is today.

About to head to GD's shop here in a few. Doing an oil change and checking out the oil pump.

You got the wizard on your team. Let us know what you guys find out.

Not 100% sure. However I did an oil change with a Subaru OEM filter and an ECU reset. All is now well. Power is back and so is the oil pressure. No more dropping. I wasn't that low on oil.

 

I believe that when the 7-8 (?) HLA's collapsed it may have caused the car to activate a new fuel map or something.

 

Yes, I had a bunch of HLA's collapse on me. So I also swapped over to solid lifters and did an adjustment.

 

All is well.

The hla are very small pasages on them and takes a tiny peice of anything to plug them but they are removeabble and can be cleaned and reused. But in your case i whould be planeing the rocker holdown posts to get the hlas closer to compensate for cam grind. The amont thats been ground is the amount that the rocker train should be planed to make geomitry right. or roller cams and valve train thats addjustabble carfull cams are matched to valve train so no mixmatching