Hemi carnage - All 8 intake valves bent after cam swap

[Wild one]

If the phazor's still good/no sheared dowel pin /timing marks still lined etc,is the camshaft still in 1 piece or is it a 2 piece camshaft now. Wouldn't be the first time i've seen a cam itself broke,it was more common on old small block Chevies,and i've never heard of it happening with a hemi cam,but it's worth jerking it out to check,as there isn't a hell'va lot left to fluck up if everything on the front is still good.

 

[dixiebandit69]

Well said. I'll take the cam out tomorrow and check back. Thanks for the response.

 

[chri5k]

This is very puzzling. Maybe the Phaser was set to "kill"?

 

[Lee Peterson]

It almost looks like is off 1 tooth on the crankshaft, might just be the picture.

 

[Brian2081]

Hello all, in the pic of the valves, look at the edge of the exhaust valves, it appears to show evidence of slight valve to piston contact.

 

[RodeoRam]

Only having done timing and balance chain work on a previous truck (Mazda), I know just enough to get me in trouble, but I have to ask, and I'll probably learn something in the process. What leads you to believe that the timing chain did not jump a link or two?

Not knowing how many miles and years your sprockets, chain, tensioner, and guide have on them, did you replace those, too? I sure would have even though they looked good mainly because I would be in there already. A bad or going-bad spring in the tensioner could have allowed the chain to jump links. Especially, since you say it happened after stopping at an intersection. Acceleration RPMs=more torque on the chain. How do the teeth look on your sprockets?

 

[Brian2081]

Ops....Intake valves. And look at pic of piston at TDC, it looks like more evidence of contact.

 

[James OBrien]

This is very puzzling. Maybe the Phaser was set to "kill"?

Ha! Nice.

 

[RedSRT4Me]

Measure the intake pushrod length. If they measure 7.85" you mixed them up.

You should have 6.6" length on intake
7.85" length on exhaust.

 

[Sandevino]

Measure the intake pushrod length. If they measure 7.85" you mixed them up.

You should have 6.6" length on intake
7.85" length on exhaust.

You beat me to it. Good call.

 

[Dodge 1500 4X4]

But how did it run so good something had to break like the cam, how do you know its not 180 degrees out now that it **** the bed, should of replaced the Phaser.

 

[Burla]

This is very puzzling. Maybe the Phaser was set to "kill"?

now that was some funny ****.

 

[dixiebandit69]

Measure the intake pushrod length. If they measure 7.85" you mixed them up.

You should have 6.6" length on intake
7.85" length on exhaust.

Guys, for the last time, the pushrods were not mixed up. You'd hang open every intake valve, and the exhausts would never open. It would never start.
This engine was running prior to the failure.

Anyway, I got back on it today, and it gets a lot weirder.

I removed the phaser, and the dowel pin was sheared off.




This phaser had been torqued to 72 ft/lbs, as is the specification.


Next, I try to remove the cam - and it will only come out a few inches. After screwing around with it for awhile, I look into the lifter holes, and see that it has spun a cam bearing...

In other news, I disassembled the phaser, and it doesn't show any signs of damage, and had no metal shavings in it.

My guess is that the cam bearing seized on the cam (after running just fine for almost an hour of operation, for some reason), shearing the dowel pin, which caused the cam to retard, and caused the pistons to hit the valves.

 

[Sandevino]

New bearings? New cam? How in all that’s holy does the pin shear off...

 

[RedSRT4Me]

Guys, for the last time, the pushrods were not mixed up. You'd hang open every intake valve, and the exhausts would never open. It would never start.
This engine was running prior to the failure.

Anyway, I got back on it today, and it gets a lot weirder.

I removed the phaser, and the dowel pin was sheared off.
View attachment 244628

View attachment 244629

This phaser had been torqued to 72 ft/lbs, as is the specification.
View attachment 244630

Next, I try to remove the cam - and it will only come out a few inches. After screwing around with it for awhile, I look into the lifter holes, and see that it has spun a cam bearing...

In other news, I disassembled the phaser, and it doesn't show any signs of damage, and had no metal shavings in it.
View attachment 244631
My guess is that the cam bearing seized on the cam (after running just fine for almost an hour of operation, for some reason), shearing the dowel pin, which caused the cam to retard, and caused the pistons to hit the valves.

Just started spinning freely till the valve contact huh?

Damn you have a mess on your hands. It would make me just want to order a new engine. I'd pitch that one and call it a day.

 

[RedSRT4Me]

New bearings? New cam? How in all that’s holy does the pin shear off...

Bending 8 push rods. Still think some of his exhaust push rods got mixed with his intake push rods. Shearing off the dowel pin was probably the aftermath of the initial piston to valve contact.

 

[Wild one]

Bending 8 push rods. Still think some of his exhaust push rods got mixed with his intake push rods. Shearing off the dowel pin was probably the aftermath of the initial piston to valve contact.

Sounds like a cam bearing seized,that would instantly shear the dowel pin,i highly doubt he had the pushrods mixed up,as it ran perfectly fine for an hour as he says. Cam bearings will occasionally seize if the new cam came through with one slightly out of spec cam journal.If the journal is a thousand or 2 to big it won't take long for that journal to seize from lack of oil supply ,and shear the dowel pin.That would explain it running good initially. If the cam bearing and cam journal clearances are to tight all the oil pressure in the world isn't going to force oil onto that bearing surface.
By chance did you happen to notice if the oil pressure seemed a little higher then normal OP,i doubt being a tight cam bearing would show up on the gauge like a tight crank bearing will,but just curious if you'd noticed any change in the oil pressure as far as being higher then normal.

 

[Wild one]

New bearings? New cam? How in all that’s holy does the pin shear off...

I doubt he replaced the cam bearings,that's a major under taking on an in chassis cam / lifter swap,it can be done,but usually isn't.

 

[chri5k]

Yeah that engine will need to come out and be torn down. Boring the cam bearing holes to accept oversize bearings will require a trip to the machine shop. Rebuilt engine exchange shops might not take the block as a good core since it will require machine shop repair and have to use non-standard bearings. If it were me I would have the cam bores enlarged and use oversized bearings. That way you will know the cam bores are all aligned properly. I have done my share of align honing cam bores when blueprinting an engine. You would be surprised what the factory accepts as good. Sorry to see / hear about the OP's predicament.

 

[James OBrien]

It all makes sense... Makes me a bit nervous since I'm about to fire my newly rebuilt motor up for the first time and I had at least my main cam bearing replaced! Definitely a locked up cam. That sucks man. What was the cam manufacturer/model?