HELP!!! Engine issues (UPDATE WITH PICS)

[imusa76]

about 5+ years ago, I installed Rebuilt heads, I have the originals stored away to be rebuilt in the future.

The rockers arms, and push rods are the originals, that's why the head is clean and the rockers are not so clean.

 

[RacerX]

What lift cam are you running?

 

[imusa76]

everything on the engine is Stock. no engine mods were done.

 

[72HCODE]

humm...

the bent rod is worrisome.

i would want a look at the lifter. Looks like the worst was averted since the valves didn't drop.

I think i would want to pull the intake manifold and take a look from inside the valley also.

 

[Qcode351mach]

I would also check the timing chain..i actually had a cam split in half on a 302 once...spin by hand make sure each valve is closing opening when it should..

 

[72HCODE]

ah yes a buddy just pointed out a stuck valve can cause the rocker to sheer off and rod to bend.

my guess is the rod bent first then the rocker sheered off from the extra force... but it would lead back to a jammed valve or possible mechanical failure inside the piston cylinder.

like if a spark plug broke inside fell on top of the piston then when the piston traveled up it would jam up against the valve the rod would bend and rocker snap.

i would guess the head has to come off to really take a look inside.

 

[imusa76]

I checked the push rod, and its not bent, it was the picture I took earlier made it look bent, its straight as can be.

I used the rubber handle of a hammer to push down on the valve and it moved down, I then compared the force needed to push it down with an other cylinder and it was the same.

so it looks like the Rocker Arm Stud was my weak link.

now the big question is how do I remove the stud and press in a new one with out removing the head?

 

[droptop73]

It looks to me like the stud started to pull out before it broke. I also do not see pushrod guide plates. What is keeping the valvetrain aligned without guideplates?

 

[kcmash]

Similar to my Cleveland Failure in college. My lifter came apart and jammed, bending the pushrod and breaking the rocker arm. Terrible pinging as the Pushrod was hitting the valve cover, crappy idle, messy drawers!

 

[RacerX]

The alignment is maintained by the rocker arms. They are rail type rockers that hug the valve stem to keep it all in line

 

[Don65Stang]

Sometimes stuff just breaks on its own and sometimes stuff breaks downstream as a result of the initial breakage.

The rocker stud is a fairly strong part to break. I think you have a lifter problem because that is a less strong part that would likely break first from a pure strength perspective.

Pull the intake and take a look. Whatever happened also do an oil change to remove any tiny metal pieces/shavings/chunks that may have entered into the oil.

 

[Qcode351mach]

I checked the push rod, and its not bent, it was the picture I took earlier made it look bent, its straight as can be.

I used the rubber handle of a hammer to push down on the valve and it moved down, I then compared the force needed to push it down with an other cylinder and it was the same.

so it looks like the Rocker Arm Stud was my weak link.

now the big question is how do I remove the stud and press in a new one with out removing the head?

I'd be inclined to do the following..Remove the plugs..spin the crank with a ratchet..Remove the dizzy cap (mark where the rotor lines up on #1 at tdc) Just verify that the valves open & close when they should in the rotation cycle & that the rotor is where should be too in the rotation cycle. Simple test will tell alot..It will verify the valve train & timing, is ok..If that checks out then I would pull both heads & have them redone..cheap insurance..Not worth taking the risk that the other studs may not let go in the near future..You need to know if it's a wear & tear metallurgy problem from when you had the heads done OR did something else cause it..

 

[72HCODE]

i agree i would have the heads rebuilt again.

and i would spin through all TDC and make sure nothing is binding a valve.

then pull the head and double check in the bore. and double check the lifter.

my experience is when one of the 8 go the problem has a good chance to appear in the other 7.

I discovered a small piece of metal clogging my upper oil valley. Traced it a piece from my valve. thought it was just the one.

nope turned out all the other 7 were about to go also and had cracks, just didn't release all the pieces into the engine yet.

 

[Jeff73Mach1]

I am going to go against the grain

If it were me I would borrow a stud removal tool and replace the broken stud, clean everything up, rinse the head down with a liberal does of kerosene, change the oil and let it go at that, obviously keeping an eye on things.

I do not like press in studs, not one single whit

I replaced all of mine with screw in studs

(and guide plates while at it)

a bigger cam and nice fresh valves

with roller rocker arms

and now my engine sits in pieces

I feel like such a schlong

 

[imusa76]

I checked TOD last night, and its on the money, so the timing did not change.

when I bought these heads, they were Rebuilds off the shelf, so the question I was thinking of last night, are they the original studs? were they replaced with cheep ones when they rebuilt the engine?

I have the Original heads to be rebuilt but I don't have the $$ to redo them heads at this time, so it looks like I'll take this head off and have the head checked out.

not what I wanted to do this weekend, there was a Car Show I wanted to go to instead

 

[marks73]

When you say off the shelf, you may want to contact where you got them. Worst they can say is No.

 

[imusa76]

I called them this morrning, its 3yrs 36k miles

so its over the 3 year mark when they looking it up.

and they gave me the number of the rebuilding company that they use, and I found out that they outsource them to a Company in Mexico, and he continued to say, they then dissasemble the heads, compleatly (but not the studs because they are pressed in) clean them, mecheine the surface that meets the block, install new vlave guides, and then replace all of the mechanical moving part (valves and springs... etc he kept going on and on)

so I asked agian, about the studs, and he said only if they show wear or were broken when they received the core head.

so that leads me to beleive, that they were either the original studs, or damaged when they pressed it in, but I'm having the local rebuilder that is going to replace the stud go through the head just in case.

 

[marks73]

Iyman, see what he wants to do them all as opposed to just 1. Price may not be that bad for the piece of mind and they are already set up anyway.

 

[imusa76]

Mark, now after what I heard from the rebuilding company, I might just take both heads and have them look them both over.

 

[Qcode351mach]

Mark, now after what I heard from the rebuilding company, I might just take both heads and have them look them both over.

Thats the right move ! Consider what happened a blessing ! You got very lucky