New engine. Aggressive Crane flat tappet, hydraulic cam. Primed oil, assembly lube on cam, lifters. Adjusted the hydraulic lifters, without engine running, but I’m no expert tuner. Tried ½ turn tighter after slack is out of pushrod. Engine started easily, but ran rough and backfired sometimes. Broke in cam for 20 minutes at 1500-2000 RPM. Drove it after for 15-20 minutes, stopped when increasingly loud noise came from engine. One rocker locking set screw came loose, and nut backed off several turns. Readjusted and tightened. Several others seemed too loose, and I adjusted. Still ran rough. Found several lifters a couple of turns loose (but locking feature of set screw in center of nut still tight.) Suspect that my adjustment procedure was not good. (Rotated engine by hand until both rockers of one cylinder seemed to be on heel of cam, adjusted both, rotated until next firing order cylinder pushrods seemed to be not moving, adjusted both, etc. Probably not a good method.)
Readjusted using different procedure: turned engine until #1 exhaust pushrod begins to move. Then adjusted that intake. Rotated engine until next cylinder in firing order exhaust pushrod began to move, adjusted that intake, etc. Then, rotated engine until #1 intake opened and just about completely closed, then adjusted #1 exhaust, etc. Used ¾ turn after slack is gone. Engine didn’t want to start. Finally started with accelerator pedal at idle, no choke, no squirting of gas with accelerator pump. Ran real rough, and backfires regularly.
What the heck am I doing wrong? Timing is 10 degrees BTDC. Checked each cylinder for hot spark—okay. Rechecked wires for proper sequence. Any help is appreciated. Is procedure okay? Is ½-3/4 turn okay? Thanks!

 

Back them back off a bit, it sounds like the intake valves are hanging open.
If it will idle, you could always adjust them like a chebby.
Start on # 1 cyl with it idleing and back off each rocker until it starts to tick the turn it back down until the click stops, then go another 1/4 turn and lock the nut.
Do this for each one and it should run fine.
This is how I did my old 351C with roller rockers on it in an old 71 Torino Gt that I had.
Jimmy

 

Hooray! Used a dial indicator to make sure the exhaust was just opening as I adjusted intake, and readjusted with ¼-1/3 turn preload. Readjusted exhausts too, though they were pretty close. Started right up!!! Thanks all. I do have a “collapsed” lifter, though. #2 exhaust has only the very light spring pressure, not at all like the other 15 lifters that have much heavier spring pressure. Ran it for a minute after adjusting that lifter like all the others. (I could easily collapse spring by hand after adjusting.) Heard lots of valve train noise so shut it off.
Can I remove this lifter with regular lifter removal tool without taking off intake? Can I disassemble and/or blow any debris out of lifter? Or would you suggest that I tighten down that “collapsed” lifter maybe until half of its spring travel is taken up, and restart engine to let it (hopefully) fill with oil or clean itself out, etc? Or do I need a new lifter? It took me several tries to get intake manifold sealed properly, so I hesitate removing it unless necessary. Thank you for your help and experience. This has been (and continues to be) a learning experience!