440 motor: Bent #1, intake and exhaust pushrods

[DocMel]

Dated 1968, 440 engine, 68 440 OEM heads, hydraulic lifters, mild cam. Basically a pretty much stock engine.  No valve train mods, Maybe 30K miles on it.  Had run like a sewing machine, no probs

Ironically, I was out on my last cruise up here in the rockies  before I store her for the winter

For about the last 50 miles I was hearing a very faint ticking.  Almost like a small header leak,  so I just let it go

I was idling at a stoplight and suddenly, the ticking got very, very loud, so I pulled over, stopped and had it towed back home  (Oil pressure went down slightly right before I shut her down (I run digital gauges), temp stayed in the norm

So today, I pulled the valve covers, saw nothing, then removed the intake manifold

The #1 cylinder pushrods, both intake and exhaust, were bent 

I removed the two, #1, hydraulic lifters.  I tried to collaspe the lifter centers on my bench by pushing down on the centers and they would not collapse.   So...............

1. Sound like the lifters (hydraulic) are shot?  (They removed from their lifter bores easily however, as they should)

2.  If they are bad, what caused it?

All the oil passages in the push rods and rockers look clear, (by flashlight)

I see no metal shaving in the valve train, lifter or intake valleys. 

Cursory inspection, for now, of the cam lobes for number 1, look OK

#1 stamped, both rockers, look ok

What happened here and what else should I look for?

[cordodge]

can you push down on the valves to see if they move? and are not stuck to the guides? not sure just a suggestion  bruce

[DocMel]

Ill be removing the drivers side head as a matter of course.   

I am thinking now that the only thing that couldve bent the pushrods at this point,( if the lifters are still good), would have to be stuck valves on number 1

[cordodge]

hey, you should be able to tell if they are stuck without removing the head and if they are not maybe you did just whined it up a little to much?

bruce

[Chryco Psycho]

My thought exactly , did the valves stick ? Generally an exhaust would sick as it runs much hotter but both on one cyl seems very strange .
The lifters should not compress easily & would seem to be normal , in a vice they should compress slowly .
 Valve spring broken or bent?

[DocMel]

Removed the head and not good news.  Catastrophic damage to #1 piston.  I found a hole in the top of the piston, about a 1/4 in diameter, and what appeared to be a metal 'slug" about the size and diameter of a pencil eraser lying of top of the piston. The intake valve on the associated head/cylinder is not fully seated and is slightly cockeyed, but I do not see any missing/broken parts:  I have no clue where/what caused the damage .  I cant imagine I ingested something

I was hoping to get another year or two out of the engine before a complete rebuild, but it look likes that will be my winter project

And I will install a set of aluminum heads and intake this time!

[roadman5312]

Sounds like the faint ticking was when whatever that object you found was holding the intake open slightly, then when it passed thru all hell broke loose. # 1 swallowed something, bent valves when piston came up.  Running air cleaner ? Got any enemies might drop a small something in the carb when your not looking ? (had that happen to a buddy once.) 

[Chryco Psycho]

Often a wing nut or similar holding the air cleaner base on can get swallowed  , missing anything ?? Sometimes people will sabotage an engine this way . Time to build it bigger & better !

[DocMel]

I run a full shaker and the wingnut is accounted for.  But low and behold, the "slug" is almost a perfect fit in the hole in the top of the piston.  Myself, I think its a matter of metal fatique in that particuar piston face.  Cant say if its cast or forged piston, but Ill say cast   When I remove that piston, itll be interesting to see if its a fit  depth wise

[Chryco Psycho]

I just refuse to use cast pistons , the cost difference to forged pistons is so minor when building an engine

[DocMel]

I would agree   Not my choice, it was the previuos owners

Ill b going with 440 source heads, mild cam and build all the way.

[DocMel]

Found what happened    Cylinder head leak at #1 superheated the top of the piston.  Top of piston failed. Slug found was part of the piston face

[roadman5312]

Found what happened    Cylinder head leak at #1 superheated the top of the piston.  Top of piston failed. Slug found was part of the piston face
[/quote

        Cylinder head leak. ? Intake gasket, head gasket ? Just curious, glad you found it. 

[RzeroB]

Found what happened    Cylinder head leak at #1 superheated the top of the piston.  Top of piston failed. Slug found was part of the piston face

"Cylinder head leak at #1 superheated the top of the piston" Hmmm? Not sure I'm following the diagnostic logic on this one. Please educate me on this...

[dutch]

what would bend the valves then?