Edelbrock head experts

Hi all, I have a conundrum for 5.0 motor experts. For the Mav, I bought a 1989 5.0 HO with Edelbrock Performer heads with stamp 6025. I wasn't convinced of it's viability (sellers say so) so filled the cylinders and valves with Marvel Mystery oil and turned it over with a wrench. It bound up solid after a near complete rotation. So I figured it had a thrown rod or other serious lower end malady. I started disassembly and 1st took off the passenger side head. After that, the motor spun freely. The cylinders looked really clean but I noticed the intake and exhaust lifters in cylinder #1 were stuck topped out. All the other lifters could be compressed with my fingers. I figured they were just pumped up and that shouldn't cause the binding anyway. Should work even with solid lifters, right?

Now I'm thinking I have the 6025 heads with 2.02 intake valves that don't work on stock short block because of piston/valve interference. But, I just measured the intakes and they were 1.90, so should work eh?

It appears this engine had run with this equipment installed (head to block oil leakage, etc.). The bind apparently is in the valve train. What else in that valve train could cause the engine bind? Testing recommendations?

Thanks in advance.

 

"so filled the cylinders and valves with Marvel Mystery oil ."

I would think this should have hydro locked at least one cyl...

 

Frank, can that happen with the plugs out?

 

Since it spins over with head removed, either there is issue with lifter(s) or maybe cam, possibly push rod too long?

 

Could also be stuck valves, Gently pop the top of each valve with a soft hammer and see if they are free.

 

Thanks. I'll try that. I'm also going to check the timing gear and make sure it's lined up and not indexed.

 

Since you were able to rotate the engine almost a complete revolution I'm of the opinion you have a valve train problem on #1 cylinder. I would concentrate there with a detailed inspection of all the parts.. Determine why the liters on #1 are stuck. Are there bent push rods, scored lifter bores, stuck valves or signs of damage with any of the components on #1?

 

Agreed, any timing issue would affect every cylinder.

 

no...didn't see where they were removed...my bad.

 

is the engine on an engine stand?

 

Don't overlook a spun rod bearing, see if any pistons are coming out of the hole.

 

Yes, it's on a stand. I'll be checking it out further tomorrow. Supposed to rain anyway.

 

That makes sense.

 

Will check that in the morning. Thanks.

 

reason I asked...
I had one on a stand that when upright or upside down it would turn all the way through. with engine turned on it's side it would almost go all the way around but stop. when turned backwards it would go almost all the way around and stop.
ran a magnet down each cylinder and found an intake washer down one cyl. upright and upside down the washer would lay flat on the piston/head and allow it to go all the way around.