How the hell does this happen??

[JTapper]

Have about 20 miles on this head swap. This head sat on my shelf all winter, untouched. I had just done the valve adjustment a few months before putting it on this motor after blowing a hole into the old head.


All the sudden while cruising at around 2.5k RPM, loud ticking commenced, this is the result:





What the hell?

[Brandon12V]

it happens. Were they new or the original?

[DTM190]

nasty! subd for curiosity

[jlevie]

The usual cause of that is improper alignment of the rocker shafts and the rocker shaft lock key not being present.

[Eecen]

Is there coolant in your head, on top of the broken/unseated rocker clamps, or is that just the camera?

[JTapper]

The usual cause of that is improper alignment of the rocker shafts and the rocker shaft lock key not being present.

Yes, and no. Was the key present? Yes. Had someone done some custom modifications to the valve cover? Yes.

The "pegs" in the valve cover had been ground down, at least 1/4". I purchased it used, and sent it off for blasting and coating. Never realized it had been modified.

The key was there, but had come lose, allowing the rocker shaft to turn, letting all the clips loose.

No damage, clocked the shaft back where it belonged, installed the lclips, and adjusted the valves again.

all is right in the world.

Is there coolant in your head, on top of the broken/unseated rocker clamps, or is that just the camera?

It's just the camera. 20 miles on fresh 40w Valvoline VR1 oil plus LED flash on camera phone = coolant look.

[JTapper]

Oh, and it sounded like this:



Yes, that is steam. I recently blew the head and have a little coolant left in the oil. Plan on changing it again in about 50 miles.

[reelizmpro]

Never seen that happen before. Maybe they weren't all the way down or got nudged when you adjusted the valves.

[JTapper]

Never seen that happen before. Maybe they weren't all the way down or got nudged when you adjusted the valves.

No, I'd installed a new (to me) valve cover that had been modified so it no longer held the rocker shaft key in place.

[reelizmpro]

Any reason why they were ground down?

[jlevie]

I've seen the key left out before with that result (and worse), but I've never heard of anyone modding the valve cover like that. I can't imagine why someone would do that.

[JTapper]

I don't know why the hell someone ground them off, but it was just plain stupid. After having that cover blasted and coated, I'm going to have a shop gob some aluminum on there and machine it smooth again. It'll be cheaper than having another cover blasted and powder coated again.

Looks like I'll be running an ugly one for a few weeks...

[CHIF8008]

dang that sucks man