I rebuilt my 427 4 bolt, and have been unable to get it to start. Got fuel, got spark, so I'm looking at valve train.

Cam is a lunati 0024...hydraulic 290/290 (232@50) .544 lift.

Here's the problem.
1. On the engine stand, set the valves at no lash + 1/4 turn. and installed it...wouldn't start.
2.In car, reset valves to no lash + 1 turn...wouldn't start.
3. Checked compression, and found 60 lbs.
4. Loosened #1 about 2 turns and got 150 lbs.
5. reset valves at no lash + nothing....got 90 lbs.
6. Loosened #1 one trun got 120 lbs.

What should I do next?

You're setting your valves wrong. Use the EO/IC method. Do a search on this site for EO/IC. However you are setting your valves you are tightening them too much and they aren't closing.

On the stand, I set #1 at TDC firing position, and adjusted Intake and Exhaust (zero lash+ 1/4trun preload) then moved 1/4 rotation, and set I&E on #8, etc through the firing order. When I redid it,after it wouldn't start, I set half the valves, rotated 360 and set the other half. (zero lash + 1 turn) following GM manual instructions.

The original setting (on the stand) was similarm but not exactly the EO/IC method, so I'll try that, next.

I'm getting good at fishing my valve covers through the fuel line, A/C, smog stuff, etc.

OK, I put a set of cut open valve covers on, so if I could get the engine running, I could adjust the valves while running. I tried the EO/IC method, and set all valves at Zero lash (no preload) Got 90 lbs compression. Opened intake valves one revolution (in other words, loose rockers) and got 120 lbs. (I tried other degrees of looseness, but got max compression at 1 revolution open. Decided to try to crank the engine... started and ran until the oil leaking from the valve covers started a small fire. Had an extinguisher handy, so no damage. I had put duct tape over the openings in the covers, but it didn't seal once it got hot.

Anyway, I got about 10 minutes on it, so I put the real covers back on, and will start it again tomorrow to finish breaking it in.

My question is, what in the world is wrong, that it will only run with sloppy valves?

Should I set them running, after the engine has been broken in?

Is it possible that you got a set of solid lifters instead of hydraulic? From the symptoms you describe, that's what it sounds like.

John,
I am positive it's hydraulic all the way. Actually, when I got my current CE coded COPO motor, I traded my running 2 bolt short block. The cam had about 1hour time on it, so I reused the heads, cam, lifters and pushrods. Only valveline change was comp roller tip rockers instead of stock stamped steel.

That's part of what baffles me. My original 427 was set with zero lash + 1/2 turn. It started right up, and ran like a scalded dog. The only thing different on the new one is the short block. When I built it, I used the same engine kit as my original 427, so I should have the same static and dynamic compression.

How are you determining "0" lash? If you're spinning the pushrods it's quite possible that you're compressing them past "0" and still able to spin them. I always use the EO/IC method but I lift up on the rocker arm at the valve stem end. I slowly tighten the rocker nut while lifting it up and down till the lash is gone. Then go 3/8 to 1/2 turn or so.

I've seen a lot of people use the spinning pushrod method and go past "0" lash.

It's really the only explanation of why backing off the rockers raises your compression that much.

Jody

Jody,
I set them a couple of ways, and zero lash was always within 1/16 turn of each other. I have tried spinning, lifing up and down, and even using a feeler gauge. At .004, two clicks on the ratchet (1/16 turn) took the lash out.

I finished breaking it in, today, and you could hear the rockers rattling. The next step is to remove the covers and set the lash at 0 + 1/4 turn, and try to run it, again.

I appreciate all the comments....I'll keep everyone tuned into my progress.