Question about heads

[demoncar71]

Ok here goes, I think I did a stupid mistake, I got a set of j heads sometime back, I took out the valves and put new ones in, no machining or anything, it has always ticked lick a bad lifter no matter what I do, I have 273 adjustable rockers, i've tried new springs, 2 sets of pushrods, 2 sets of lifters, now all of a sudden I have bad spark knock at idle, do I need to pull these heads and have the valves redone at a machine shop ?

 

[cannucky]

What do the plugs look like ? did you at least hand lap them in ? how old is the fuel ? does the cam have a flat lobe ? is the carb clean and functioning correctly ? you haven't given us much info here really , why did you start throwing parts at it ? Are you absolutely sure the ticking isn't a header / exhaust leak ? my car ticks when the collector or header gaskets are leaking .

 

[MOPAROFFICIAL]

Spark knock...like does it do random little pops out the exhaust ...or even carb and or sometimes run on when you shut it off ?
You might have burnt valves .

 

[66fs]

Just for the record, never put valves in a head without having them ground. If you ever ground valves, you would know how far off they are. Let alone the right angles for each cut on the seats to get the right seat diameter and width. A good valve job is the key to good efficiency and power. Your engine should fire before one revolution. Your cam could be worn out, round lobes, and nothing will fix that but a new cam.

 

[demoncar71]

Rebuilt short block, new cam and lifters, its not a header leak, it has 0 miles on motor other than in my parking lot and break in

 

[nm9stheham]

The term 'bad spark knock' is hard to understand without hearing. Is it a REALLY loud knock? I'd be concerned that a valve is stuck and slamming the piston. (Old fuel, gumming the guides.)
Another possibility is the intake stuck open on a cylinder and the spark on that cylinder firing back up into the intake.
With the new cam, what oil did you use and did you follow standard break-in procedures with the engine revved, varying around the 2000 range, for 20-30 minutes?

 

[gtsdude]

At the very least you should lap new valves in and look at the valve and seat to see if the angles are the same after lapping. And also check the guide clearance.