First off, I don't know much about valve trains. I am by no means a engine builder. I have extensive mechanical experience but never ventured outside of stock bolt on and take offs.

Here is the situation, picked up a CHEAP 460, supposedly rebuilt, never fired, it was cheap enough that I figured it was worth the risk.

Threw it in truck, fired it up, broke it in, sounded great. Drove it around the yard a bit and seems to have lots of power and no smoke, but shut her down and will never restart, i keep finding loose (not bent or damaged) pushrods.
Put the pushrod back in and starts and runs great, i have done this about 5 times...... I spent hours researching and broke down and bought an adjustable pushrod to determine what I thought was correct length, like one size longer than what was already in there. But the problem keeps occuring! HOWEVER, this time i noticed odd wear on the intake valve keeper/retainers! Finally a clue!










So, I assume that the rocker arms are incorrect, but then again, I dont know much, so thats why I am writting this. It appears that the rocker are is just rubbing all over the valve spring "retainer" and not just on the tip of valve like it should. Ok, thats fine and dandy, but how do i figure out what arms to replace them with? I am thinking roller rockers (again I don't really know anything about roller rockers but i have seen pictures in the catalogs). I feel like with a roller rocker the "arm" would be "above" the roller, thus up higher and less likely to come in contact with the valve keepers.

There are no marks on the exhaust valves and it appears there is more valve "stem" sticking out of the top of the spring so I assume that is why they do not hit. Also the rockers have different markings but do not look physically different.




Anybody have any guidance? Here is what I know about the engine

Block-unknown
Heads Dove-C
Cam, lifters, springs and i believe retainers- Comp Cams 4x4 Extreme

Like I said, when i reset all the pushrods, it starts and runs great, 1 time.

I would really like to figure out what this last piece of the puzzle is. Tonight i drug it back in the garage to remove the heads because I was so frustrated. I was going to replace the heads with another pair of D3VE-A2A heads I had laying around which do not have adjustable rockers just because I have seemed to be getting nowhwere.






But when i was prepping the heads for removal I noticed the wear and the pattern that it was only intake valves, and that the intake valves didn't stick out as far from the spring as the exhaust valves did. Suddenly i figured I should ask for some help before going through all the work of switching heads if it may be as simple as bolting on some different rocker arms.

Please tell me someone has some insight! I'm desperate here
Thank you very much in advance!

 

Or do I just need much longer pushrods on the intake valves?

 

as said in the other post, i think they put the wrong intake valves in the head.
lets see what the guys here have to say about it.

 

do you have the cam specs?
the stock rocker arms are really only good to about .5 lift, after that then you should be going to roller rockers and new studs and guideplates.


also how are you setting the rockers? the factory setup (which you have) are not adjustable, you just install the nut till the rocker bottoms out on the shoulder of the stud and torque to 25ft/lbs. any adjustment has to be done by getting longer or shorter pushrods.


if It was me, I would ditch the factory rockers and studs and install roller rockers, studs and guide plates. Scorpion, Harland Sharp, Crane and Comp Cams all make decent roller rocker kits for these engines. just make sure you get rockers made for the Ford and not the Big Block Chev (they will be a true 1.73 ratio not 1.7 like the BBC)


rgds
Mike

 

X2 above...you either have too much lift or the valves are not correct. There may have been too much material removed from the end of the valve stem. The old engine might have needed new valves but someone may have tried to save money by grinding the stems back into shape.


I don't know the spec but there should be an installed height you could measure.